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FOOD INSPECTION AND ANALYSIS. 



FOR THE USE OF PUBLIC ANALYSTS, HEALTH 

OFFICERS, SANITARY CHEMISTS, 

AND FOOD ECONOMISTS. 



ALBERT E. LEACH, S.B., 

Chief of Ihe Denver Food and Drug Inspection Laboratory, Bureau of Chemistry, U. S. De- 
partment of Agriculture; formerly Chief Analyst of the Massachusetts 
Stale Board of Health. 




SECOXD EDITIOX, REVISED AXD ENLARGED. 
FIRST THOISAND. 



NEW YORK: 

JOHN WILEY & SONS. 
London: CHAPMAN & HALL, Limited. 
1909. 






Copyright, 1904, 1909, 

BY 

ALBERT E. LEACH. 



Entered at Stationers' Hall. 



^a^2^\mi 



'Eltf ■^'cifntific Press 
^'cui 11 ink 



PREFACE TO SECOND EDITION. 



During the five years that have elapsed since the appearance of 
the first edition, much progress has been made in food control work 
both in America and in Europe. In the United States the passage of 
the national pure food law, perhaps more than any other single factor, 
has contributed toward this, and has itself been the direct cause of 
ncreased activity on the part of many of the States. New standards 
have been adopted, many new methods have been tried out and found 
useful, and in some cases old ones have been displaced. 

The most important of these changes and improvements have, it is 
believed, been embodied in the present edition, and include new material 
and modern methods of analysis covering a wide variety of subjects. 
Notable among these are meats and meat extracts, flour (including 
methods for determining the grade and for the detection of bleaching) 
noodles and Italian pastes, paprika, prepared mustard, tea, coffee, cocoa 
products (including milk chocolate), ice cream, maple products, honey, 
oils (including the Polenske number and Bomer's phytosterol-acetate 
test for vegetable oils), distilled liquors, preservatives (notably benzoic 
acid), etc, 

A separate chapter on the refractometer, its varieties and application 
to food analysis has been introduced; also a separate chapter on flavor-: 
ing extracts, including the lesser used extracts of almond, peppermint, 
wintergreen, rose, cassia, and cloves. 

At the time the importance of a new edition seemed specially mani- 
fest, the author's health was such that it would have been impossible 
for him to personally undertake the work, and had it not been for his 
friends it could not have been accomplished. Indeed, the work of 
revision has been due to the untiring energy of Dr. A. L. Winton, Chief 
of the U, S. Food and Drug Inspection Laboratory at Chicago, who 
out of a busy life has taken entire charge of the details of the task, 



vi PREFACE. 

supplying most of the new material, as well as introducing much that 
is original as a result of his ripe experience. To him, therefore, above 
all others, the author here expresses his deep appreciation and gratitude. 

Special thanks are also extended to Dr. W. D. Bigelow, Chief of the 
Division of Foods of the Bureau of Chemistry, Washington, for his 
substantial work in revising the chapter on flesh foods, which includes 
much of his recent research along this line; also to Dr. T. B. Osborne, 
Chairman of the Committee on Protein Nomenclature of the American 
Physiological Society and of the Society of Biological Chemists, who 
has revised the classification of nitrogenous bodies; and finally to Mr. E. 
J. Shanley for his help in reading proof. 

Denver, Colorado, September, 1909. 



PREFACE TO FIRST EDITION. 



In the preparation of the present work, the requirements of the public 
analyst are mainly kept in view, as well as of such officials as naturally 
cooperate with him in carrj'ing out the provisions of the laws dealing 
with the suppression of food adulteration in states and municipalities. 
To this end special prominence is given to the nature and extent of adul- 
teration in the various foods, to methods of analysis for the detection of 
adulterants, and to some extent also to the machinery of inspection. 

While the analyst may not in all cases have directly to deal with the 
minutlcB of food inspection, his work is so closely allied therewith that 
this branch of the subject is of vital interest and importance to him. 
Indeed, in many smaller cities one official often has charge of the entire 
work, combining the duties of both inspector and analyst. 

Endeavor has been made, furthermore, to deal with the general com- 
position of foods, and to give such analytical processes as are likely to 
be needed by the sanitary chemist, or by the student who wishes to 
determine the proximate components of food materials. 

It has been thought best to include brief synopses of processes of 
manufacture or preparation of certain foods and food materials, in cases 
where impurities might be suggested incidental to their preparation. 

In view of the fact that Massachusetts was the pioneer state to adopt, 
over twenty years ago, a practical system of food and drug inspection, 
and for many years was the only state to enjoy such a system, no apology 
is perhaps needed for more frequent mention of Massachusetts methods 
and customs than those of many other states, in which the food laws 
are now being enforced with equal zeal and efficiency. 

Considerable attention has been paid in the following pages to the 
use of the microscope in food analysis. Of the figures in the text illus- 



viu PREFy4CE. 

trating the microscopical structure of powdered tea, coffee, cocoa, and 
the spices, fifteen have been reproduced from the admirable drawings 
of Dr. Josef Moeller, of the University of Graz, Austria. Acknowledg- 
ment is gratefully given Dr. Moeller for his kind consent to their use. 

The photomicrographs in half-tone, forming the set of plates at the 
end of the volume, were all made in the author's laboratory, and may 
be divided into three classes: ist, illustrations of powdered pure foods 
and food products, as well as of powdered adulterants; 2d, types of 
adulterated foods, chosen from samples collected from time to time in 
the routine course of inspection; and 3d, photographs of permanently 
mounted sections of foods and adulterants. 

While recent works covering the whole field of general food analysis 
are comparatively few, the number of treatises, monographs, government 
bulletins, and articles scattered through the journals, dealing with special 
subjects relative to food and its inspection, is surprisingly large, and from 
a painstaking review of these much information has been culled, for which 
it has been the author's intention at all times to give credit. 

Special mention sliould here be made of the valuable publications of 
the U. S. Department of Agriculture, both the bulletins issued from 
Washington, and those from the various experiment stations, an ever- 
increasing number of which are becoming engaged in human food 
work. The author has freely drawn from these sources, and especially 
from the data and material furnished by his coworkers in the recent 
and still pending labor of preparing food methods for the Association of 
Official Agricultural Chemists, and he wishes to extend his thanks to 
all of them for their assistance. Appreciation is also expressed for the 
care and discrimination shown by Mr. L. L. Poates in the preparation of 
the cuts. Thanks are especially due to Mr. Hermann C. Lythgoe, 
Assistant Analyst of the Massachusetts State Board of Health, for his 
invaluable cooperation, and to Dr. Thomas M. Drown for helpful hints 
and suggestions. 

Boston, Mass., July i, 1904. 



TABLE OF CONTENTS. 



CHAPTER I. 

PAGE 

Food Analysis and Official Control 1-13 

Introductory, i. Food Analysis from the Dietetic Standpoint, 2. Systematic 
Food Inspection; Functions of the State Analyst; Standards of Purity; Na- 
ture of Analytical Methods, 3-5. Adulteration of Food, 5. Misbranding, 6. 
A Typical System of Food Inspection, 6-9. Practical Enforcement of the Food 
Laws; Publication; Notification; Prosecution, 10. 

References on Food Inspection and Official Control, 11. 

CHAPTER II. 

The Laboratory and its Equipment 14-38 

Location, 14. Floor; Lighting; Benches, 15. Hoods, 16. Sinks and 
Drains, 17. Steam and Electricity; Suction and Blast, 19. Apparatus, 20- 
25. Reagents, 26-35. Equivalents of Standard Solutions; 36-37. Indica- 
tors, 38. 

References on Laboratory Equipment, Reagents, etc., 38. 

CHAPTER III. 

Food, its Functions, Proximate Components, and Nutritive Value 39-52 

Nature and General Composition of Food; Fats, 39. Protein, and 
Classification of Nitrogenous Bodies, 40. Proteins, their Subdivisions, Occur- 
rence, and Characterstic Tests, 40-45. Amino A'-ids, etc., 45. Alkaloids; 
Nitrates; Ammonia; Lecithin; Carbohdyrates aad their Classification, 46. 
Organic Acids; Mineral or Inorganic Materials; Fuel Value of Food; 
Bomb Calorimeter, 47-48. 

References on Dietetics and Economy of Food, 49. 

CHAPTER IV. 

GENER.A.L Analytical Methods 53-80 

Expression of Results, 53-54. Preparation of Sample, 55. Specific Gravity; 
Methods and Apparatus, 55-60. Determination of Moisture, 61. Deter- 
mination of Ash, 61-63. Continuous Extraction with Volatile Solvents, 63-68. 
Separation with Immiscible Solvents, 68. Determination of Nitrogen, 69-73. 



TABLE OF CONTENTS. 



Determination of Free Ammonia; Determination of Amido Nitrogen, 74. 
Determination of Carbohydrates, 74. Poisoned Foods, 74. Detection and 
Determination of Arsenic, 75-76. Colorometric Analysis, 77. Tintometer, 
78. 
References on General Food Analysis, 79. 

CHAPTER V. 

The Microscope in Food Analysis 81-99 

Microscopical vs. Chemical Analysis, 81. Technique of Food Microscopy, 
82. Apparatus and Accessories, 82-84. Preparation of Vegetable Foods for 
Microscopical Examination, 85. Miscroscopical Diagnosis, 86. Vegetable 
Tissues and Cell Contents, under the Microscope, 87-90. Microscopical 
Reagents, 90-93. Microchemical Reactions, 90-93. Photomicrography; 
Appurtenances and Methods, 93-98. 

References on the Microscope in Food Analysis, 98. 



CHAPTER VL 

The Refractometer 100-123 

Butyro-refractometer, loi. Refractometer Heater, 102. Manipulation, 
102-104. Equivalents of Refractive Indices and Butyro-refractometer Read- 
ings, 105-106. Temperature Correction, 107. Abbe Refractometer, 108. 
Construction; Manipulation, 109-111. Immersion Refractometer, 111-112. 
Manipulation, 113-115. Equivalents of Refractive Indices and Immersion 
Refractometer {•leadings, 116-119. Strength of Solutions by Refractometer 
120. Temperature Corrections, 121. 
References on the Refractometer, 122. 



CHAPTER VIT. 

Milk and Milk Products 124-210 

Composition and Characteristics of Milk, 124. Milk Sugar; Milk Proteins, 
and other Nitrogenous Bodies, 125. Milk Fat; Citric Acid; Composition of 
the Ash, 126-127. Fore Milk and Strippings, 128. Colostrum; Frozen Milk; 
Fermentations of Milk, 129. Analysis of Milk, 130. Specific Gravity, 131-133. 
Total Solids, 133. Ash, 134. Fat, by E.xtraction, by Centrifugal, and by Re- 
fractometric Methods, 134-144. Proteins; Casein, 145. Albumin; Other 
Nitrogenous Bodies, 146. Milk Sugar, by Optical Methods, 147 149, by 
Fehling's Solution, 149-151. Relation betvi'een the Various Milk Constituents; 
Calculation by Formulae, 151-153. Acidity, 153. ^^oiled Milk, 155. Modi- 
fied Milk and its Preparation, 155-157. Prepared Milk Foods, Milk Powders, 
and Artificial Albuminous Foods, 157-159. Koumis, 158. Kephir, 159. 

Milk Adulteration and Inspection; Milk Standards, 159-161. Forms of 
Adulteration, and Variation in Standard, 161-162. Rapid .\pproximate 
Methods of Examination, 163-164. Examination of Milk Serum; Constants, 
164-168. Systematic Routine Examination, 168. Analytical Methods for 
Solids, Fat, and A.sh, 170-173. Added Foreign Ingredients. 173. Coloring 
Matters and their Detection, 174-177. Preservatives, their Relative Efficiency 



TABLE OF CONTENTS. xi 

PAGE 

and their Detection, 177-185. Added Cane Sugar, and Starch, 185. Added 
Condensed Milk; Analysis of Sour Milk, 186. 

Condensed Milk; Composition, Standards, Adulteration, 186-188. Methods 
of Analysis, 188-191. Calculation of Fat in Original Milk, 192. 

Cream; Composition, Analytical Methods, Standards, Adulterants, 193-195. 
Gelatin in Cream, 195-196. Sucrate of Lime in Cream, 196-198. 

Ice Cream; Standard, Fillers, 198-199. Analytical Methods, 199-201. 

Cheese; Composition, Varieties, 201-202. Standards; Adulteration, 
203-204. Analytical Methods, 188-191. Separation and Determination of 
Nitrogenous Bodies, 205-206. Lactic Acid; Milk Sugar; Foreign Fat, 207. 

References on Milk and its Products, 208. 



CHAPTER VIII. 

Flesh Foods 21 1-260 

Meat; Structure and Composition, 211. Proximate Components of the 
Common Meats, 212-217. Meat Inspection, 217. Standards, 218. Meat 
Preservatives, 218. Curing, 219. U.se of Antiseptics; Effect of Cooking, 220. 
Canned Meats, 221. Sausages, 223-224. Analytical Methods, 225. Fats 
of Meats, 226-227. Classification, Separation, and Determination of Nitrog- 
enous Bodies, 228-231. Determination of Gelatin, 231. Determination of 
Nitrates, 232. Preservatives and their Detection, 232. Starch in Sausages, 
233. Horseflesh in Sau.sages, and its Detection, 234-238. Muscle Sugar, 238. 
Coloring Matters and their Detecticn, 238-239. Detection of Frozen Meat, 
23r. 

Meat E.xtracts; Character and Standards, 240-241. Composition, 242-244. 
Meat Juices, 245. Miscellaneous Meat Preparations, 246. Methods of 
Analysis, 246-249. Separation of Nitrogenous Compounds, 249-253. Acidity, 
253. Preservatives; Glycerol, 254. 

Fish; Structure Composition, and Methods of Analysis, 254-255. Crus- 
taceans and Mollusks, 256. Analytical Methods; Preservatives in Fish and 
Oysters, 257. 

Concentr:,t-'d Foods for Armies and Campers, 257. 

References on Flesh P'oods, 258. 



CHAPTER IX. 

Eggs 261-270' 

Nature and Composition, 261. The Egg White and its Nitrogenous Com- 
pounds, 262. Prej)aration of Albumin; The Egg Yolk and its Composition, 
263. Composition of the Ash, 264. Analytical Methods; Determination of 
Lecithin, 265. Preservation of Eggs, 266. Cold Storage Eggs, 267. Physical 
Methods of Examination, 267. Opened Eggs; Desiccated E^ggs, 268. Egg 
Substitutes, 269. Custard Powders, 270. 
References on Eggs, 270. 



Xll TABLE OF CONTENTS. 

CHAPTER X. 

PAGE 

Cereals and their Products, Legumes, Vegetables, and Fruits 271-364 

Composition of Cereals, Vegetables, Fruits, and Nuts, 271-276. Methods 
of Proximate Analysis, 276-279. Carbohydrates of Cereals, 279. Starch; 
Detection, Varieties, Classification, Microscopical Examination, 279-283. 
Starch Determination, by Direct Acid Conversion and by Diastase Methods, 
283-284. Cellulose; Crude Fiber, 285. Pentosans and their Determination, 
285-294. Separation and Determination of the Carbohydrates of Cereals, 295- 
296. Proteins of Cereals and Vegetables; Sepiration and Methods of Analysis, 
296-298. Proteins of Wheat, their Separation and Determination, 298-300. 
Proteins of Other Cereals and Vegetables, 300-301. Ash of Cereals and 
Vegetables; Scheme for Ash Analysis, 301-305. Microscopy of Cereal Pro- 
ducts, 305-311. 

Flour; Milling, 311. Composition, 312. Damaged Flour; Ergot, 313. 
Adulteration, 314. Alum; Bleaching, 315. Inspection and Analysis; Fine- 
ness, 316. Pekar's Color Test; Absorption and Dough Test; Expansion of 
Dough, 317. Baking Tests, 317-319. Proximate Constituents; Gluten, 319. 
Protein; Acidity, 320. Detection of Bleaching; Nitrites, 321. Bamihl Gluten 
Test, 322. 

Bread; Composition; Varieties, 323-325. Methods of Exar in tion, 325- 
326. Adulteration of Bread; Alum, 326. Cake, 327. 

Leavening Materials; Yeast, 327. Compressed Yeast; Dry Yeast, 328. 
Composition and Microscopical Examination, 329. Yeast Testing; Available 
Carbon Dioxide, 330. Starch in Compressed Yeast, 331. 

Chemical Leavening Materials; Baking Powders, their Classification and 
Composition, 332-334. Adulteration, 334. Cream of Tartar and its Adultera- 
tion, 335. Analysis of Baking Chemicals, 336. Carbon Dioxide, 336-339. 
Tartaric Acid, 339-343- Starch, 343. Aluminum Salts, 344. Other In- 
gredients, 345-346. 

Semolina, Macaroni, and Edible Pastes; Noodles, ^547-348. Adul- 
teration; Analytical Methods; Lecithin-Phosphoric Acid, 349. Colors, 349- 
352. Shredded Wheat, 352. 

Prepared Cereal Breakfast Foods; Nature and Composition, 352-354. 
Analytical Methods, 354. 

Infants' and Invalids' Foods, 354. Classification, 355. Composition, 356. 
Diabetic Foods, 357-358. Analytical Methods, 359-360. 

References on Cereals, Vegetables, etc., 361. 

References on Leavening Materials, 364. 



CHAPTER XI. 

Tea, Coffee, and Cocoa 365-407 

Tea; Varieties, Method of Manufacture, Composition, 365-368. Analytical 

Methods, 368. Extract; Tannin, 370-372. Theine, or Caffeine, 372-374. 

Adulteration and Detection of Adulterants; Facing, 374. Spent Leaves, 375. 

Foreign Leaves; Stems and Fragments, 376. Added Astringents; Tea Tablets, 

377. Microscopical Structure, 378. 

Coffee; Nature, Composition, Effect of Roasting, 379-381. Substitutes 

and Adulterants, 382. Analytical Methods; Caffetanic Acid, 382-383. 



TABLE OF CONTENTS. xiii 

PAGE 

Caffeine, 384. Adulteration; Imitation Coffee; Coloring, 384. Glazing; 
Methods, 385. ]\Iicroscopical Examination, 386. Chicory; its Microscopical 
Structure, 386-388. Composition of Chicory, and its Determination in Coffee, 
389. Date Stones; Hygienic Coffee; Substitutes, 390-392. 

Cocoa and Cocoa Products; Composition, Methods of Manufacture, 392- 
395. Theobromine and Nitrogenous Substances, 396. Milk Chocolate; Com- 
pounds, 397. Analytical Methods, 398. Starch; Sucrose; Lactose, 399. 
Theobromine and Caffeine, 400-401. Adulteration, and Standards of Purity, 
402. Addition of Alkali, Microscopical Structure, 403-404. Cocoa Shells; 
Added Starch, Sugar, Fat and Colors, 405. 

References on Tea, Coffee, and Cocoa, 406. 



CHAPTER XII. 

Spices 408-470 

Methods of Proximate Analysis Common to all the Spices, 408. Moisture; 
Ash; Ether, and Alcohol Extract; Nitrogen; Starch; Crude Fiber; Volatile 
Oils, 409-411. Microscopical Examination, 412. Spice Adulterants, 412-413. 

Cloves; Composition, 412-415. Tannin, 415. Microscopical Examination, 
416. Clove Stems, 417. Adulteration and Standard of Purity; Exhausted 
Cloves, 418. Cocoanut Shells, 419. 

Allspice; Composition, 420. Tannin Equivalent, 421. Microscopical 
Structure, 422-423. Adulteration and Standard of Purity, 424. 

Cassia and Cinnamon; Composition, 424-425. Microscopical Structure, 
426-427. Adulterants; Standard, 428. Foreign Bark, 428. 

Pepper; Composition, 428-432. Nitrogen Determination, 432. Piperin, 
433. Microscopical Examination, 433-434. Adulteration and Standards, 435. 
Pepper Shells and Dust, 435. Olive Stones, 436. Buckwheat, 437. I>ong 
Pepper, 438. 

Red Pepper; (Cayenne, Paprika, etc.). Nature; Varieties: Composition, 
439-441; Microscopical Structure, 441-443. Adulteration, 443-445. Added 
Oil in Paprika, 445. 

Ginger; Composition, 445-446. Exhausted Ginger, and its Detection, 447- 
448. Microscopical Structure, 449. Adulteration and Standard, 450. 

Turmeric; Composition, 450. Microscopical Structure, 451. Detection, 

443- 

Mustard; Composition, Preparation, 453-456. Mustard Oil Determina- 
tion, 457. Microscopical Structure, 458. Adulteration and Standards, 459. 
Coloring Matter, 460. Prepared Mustard; Composition, Adulteration, 460. 
Analytical Methods, 461. 

Nutmeg and Mace; Composition of Nutmeg, 462-463. Microscopical Struc- 
ture of Nutmeg; Adulteration; Standard of Purity, 464. Composition of 
Mace, 465. Microscopical Structure; Adulteration; Standard, 466. Bom- 
bay or Wild Mace and its Detection, 467. Macassar Mace, 468. 

References on Spices, 468. 



XIV T/lliLli Oh CONTIiNTS. 

(■iiai"'I'i;r \iii. 

PAOR 

l'j)iiii.i'; Oils and I*' a is 47 r 564 

Nature and I'roijcrtics, 471 . I'atly Acids, 471 472. Saponilkation, 472. 
Analysis; Raruidity; Jud^incnt as to I'urity; I'iltcring, Weighing, and 
Measuring I'ats, 47.5. Specific: (Gravity, 474 476. Viscosity, 477. Melting- 
point, 4X0. Keicliert-Meissl Process for Volatile l-atty Acids, 481-482. Po- 
icnske Number, 485. Soluble and Insoluble I'alty Acids, 484 486. Sa[)onifica- 
tion Number, 486. Iodine Absorption Number; Uubl's Method, 487 490. 
nanus's Method, 491. Wijs's Method, 492. Bromine A])Sor[)tion Number, 
49249,^. 'rhermalTests, 493. Maumen(^ Test, 494. Hrominalion Test, 494- 
497. The Acetyl Value, 497-498. The Valcnta and iviaidin 'IV.sts, 499. 
Free I''atly Acids, soo- Titer Test, 500 501. Un.saijonifiable Matter, 501. 
Cholesterol .iiid i'hylostciol, 502. Se|)aralion and Crystallization, 503-506. 
B(")mer's i'liytoslcrol A(clale 'i'esi, 507. Conslaiils of iMJible Oils and Fats, 
508 509. Parrairni; M i( roscopii a! iOxamiiiallion of ( )ils and I'ats, 510. 
Olive Oil, 511. Composition and Adulteration, 512. Standards, 513. Tests 
for Adulteration, 513-515. Cottonseed Oil, 516. liechi's 'lY'st, 517. Ilal- 
phen's Test, 518. Sesame Oil, 518, .Adulterants and'I'ests, 519. Rajie Oil, 
520. Tests, 521. ('orn Oil, 521. Sitosterol, 522. I'eanut Oil, 522. Adul- 
terants; Keiuird's Method, 523. Bellier's Method, 524. Mustard Oil, 525. 
Poppy.seed Oil, 526. Sunflower Oil, 526. Rosin Oil, 527. Cocoaiml Oil, 528. 
Cocoa Butter; Tallow, 529. 

Butler, 529. Composition, 530. lOffecIs of I'ceding, 531. .Xiialytical 
Methods, 531. Water, 531 533. I''at, 533. Ash; Casein; Milk Sugar; 
i.aclic Acid; Sail, 534. Standard Buder l''al, 535. .Adulteration, 535. 
Colors, 535 537. i're.scrvalives, 538 53(). Renovated or Process Butter, 540. 
Oleomargarine; Manufacture, 541. Coloring; Detection of I'alm Oil, 542. 
Adulterants; llealthfulness, 543. Distinction from Butter, 544. Distin- 
guishing Tests for Bulter, Process Butter, and Oleomargarine, 546. ikityro- 
refractonieter, 54^) 548. keichert Meissl Number; S|)eciric (iravity; Foam 
Test, 549. Milk 'I'est, 550. Curd Tests, 551. Microscopical iCxaminalion, 
552-55,?- I'"'>i"<'ign Oils, 554. 

Lard, 554. Composilion; Lard ( )il, 555. Coni|)ound Lard; Standards; 
Adulteration, 550. P'oreign Oils, 557. Micro.scopical F.xamination, 557 558. 
Analysis of Lard and Lard Substitutes, 559. Fffects of I'\r(ling, 560. 

References on Ivlible ( )ils and I'"ats, 561. Refc-rences on I>utter, 562. Refer- 
ences on Lard, 563. 



CIIAI'Tl.k \1\'. 

SUOAli AND SaCCIIAIMNI'. PkODUCTS 565-652 

Nature and ChLssihcation, 565. Cane Sugar; Standard, 566. Sugar Cane; 
Manufacture of Cane Sugar, 567. Com|)osition of Cane Sugar IVoducls, 568. 
Sugar Beet; Manufacture of Beet Sugar, 569. Refining Sugar; Maple Pro- 
ducts, 750. Ct)m])ositions, Standards, and Adulteration of Maple Products, 
571-572. Sorghum, 573. Crape Sugar, 573. Levulo.se; Malt Sugar, 574. 
Dextrin; Commercial Clucose, 575. Standards and llealthfulness of (ilucose, 
570. Milk Sugar; Rallinose, 577. 



TABLE Oh' CONTENTS. XV 

PAGE 

The Polariscope and Saccharimetry, 578-583. Comparison of Scales and 
Normal Weights, 583. Specific Rotary Power; Birotation, 584. 

Analysis of Cane Sugar and its Products; Tests for Sucrose, 585. Moisture; 
Ash; Xon-sugars; Sucrose Determination by Polariscope, 586-587. Inversion; 
Clerget's P'ormuia, 588. Detection and Determination of Invert Sugar, 589. 
Ultramarine in Sugar; Copper Reduction, 590. Volumetric Pehling iVocess, 
591-592. Gravimetric Tehling Methods, 593. Defren-O'Sullivan Method, 
594-597. Mun.son and Walker Method, 598-607. Allihn Method; Elec- 
trolytic Apparatus 608-612. Sucrose Determination by Fehling Solution, 612. 

Analysis of Molasses and Syrups, 613. Solids; Ash; Polarization, 613- 
620. Double Dilution Method of Polarizing; Raffinose Determination, 620. 
Adulteration of Molas.ses and Standards, 621. Glucose Determination, 621- 
624. A.shing Saccharine Products, 624. Tin Determination, 625. 

Separation and Determination of Various Sugars, 625-626. 

Analysis of Maple Products, 627. Moisture; Ash; Malic Acid Value, 627. 
Lead Number, 628. Hortvet Number, 628-630. Sy's Method, 630. 

Analysis of Glucose; Polarization Formula;, 630-631. Dextrin; Arsenic in 
Glucose, 632. 

Honey; European, 633. Canadian; American; Hawaiian, 634-635. 
Adulteration, 636-638. 

Analysis of Honey; Moisture; Ash; Polarization, 639. Reducing Sugars; 
Levulose; Dextrose; Sucro.se; Dextrin, 640. Acids; Glucose, 641. Invert 
Sugar; Di.stinction of Honeydew from Glucose, 642. 

Confectionery; Standard; Adulteration; Colors, 645. Analysis of Con- 
fectionery; Mineral Adulterants, 646. Father Extract; Paraffine, 647. 
Starch; Polarization, 648. Alcohol; Colors; Arsenic, 649. 

References on Sugars, 650. 



CHAPTER XV. 

Alcoholic Beverages 653-758 

Alcoholic Fermentation, 653. Alcoholic Liquors and State Control, 654. 
Liquor In.spection, 655 -656. Analytical Methods common to all Liquors; 
Specific Gravity, 657. Detection and Determination of Alcohol, 657-660. 
Alcohol Tables, 661-674. The Ebulioscope, 675-676. Extract; Ash; Arti- 
ficial Sweeteners, 677. 

Fermented Liquors; Cider, 678. Manufacture and Comfxjsition, 678-681. 
Adulteration, 682. Perry, 683. Wine, 684. Classification of Whines, 685. 
Comfxjsition and Varieties, 686-689. Standards, 689-691. Adulteration, 
691 695. Analytical Methods for Wine; Extract; Acidity, 696. Extract 
Table, 697-699. Tartaric Acid, 701. Malic Acid, 702. Sugars; Glycerin, 
703. Tannin, 704. Foreign Colors, 704-706. 

Malt Liquors; Beer, 707. Varieties of Beer and Ale, 708. Composition, 
709. Malt and Hop Sub.stitutes, 710. Adulteration and Standards, 711. 
Malted vs. Non-malted Liquors, 712. Pre.servatives; Arsenic, 713. Tem- 
perance Beers, 714. Analytical Methods, 714. Alcohol, 715. Extract, 715- 
722. Original Gravity, 722-724. Sugars; Dextrin; Glycerine; Acids, 724. 
Protein; Phosphoric Acid, 725. Carbon Dioxide, 726. Bitter Principles, 726- 
727. Arsenic, 728. Malt Extract, 729. 



XVI TABLE OF CONTENTS. 

PAGE 

Distilled Liquors; Standards for Spirits, 730. Fusel Oil, 731. Whiskey, 731. 
Manufacture 731-732 Standards, 733-734. Composition, 734-737. Adultera- 
tion, 738. Brandy; Manufacture; Composition, 739. Standards, 740. Adul- 
teration, 741. Rum; Composition, 742. Standards, 742-743. Gin, Composi- 
tion, 744. Analytical Methods for Distilled Liquors; Extract, Acids; Esters; 
Aldehydes, 745. Furfural, 746. Fusel Oil, 746-749. Methyl Alcohol, 749- 
752. Caramel, 752-753. Opalescence Test, 753. 

Liqueurs and Cordials, 754. Analysis of Liqueurs, 755. 

References on Alcoholic Beverages; on Beer, 756. 

References on Cider and Wine, 757; on Distilled Liquors, 758. 



CHAPTER XVI. 

Vinegar 659-779 

Acetic Fermentation; Varieties of Vinegar, 759. Manufacture and Com- 
position, 760-761. Cider Vinegar, 760. Wine Vinegar, 761. Malt Vinegar, 
762. Spirit, Glucose, and Molasses Vinegars, 763. Wood Vinegar, 764. 
Analytical Methods; Density; Extract; Ash; Phosphoric Acid, 764. Nitro- 
gen; Acidity, 765. Alcohol; Mineral Acids, 766. Malic Acid, 767. Lead 
Precipitate, 768. Potassium Tartrate; Sugars, 769. 

Adulteration of Vinegar; Standards, 770-771, Artificial Cider Vinegar, 
772. Character of Residue and Ash, 772-773. Character of Sugars, 774. 
Tests, 775. Composition of Artificial Cider Vinegars, 776. Detection of 
Adulterants, and Mineral Impurities, 777-778. 
References on Vinegar, 778. 



CHAPTER XVII. 

Artificial Food Colors 780-814 

Extent of Use; Objectionable Features, 780. Toxic Effects, 781. Harm- 
ful Mineral Colors, 782. Harmful Organic Colors, 783. Harmless Mineral 
Colors; Harmless Organic Colors, 784-786. Use of Colors in Confectionery, 
786. Vegetable Colors, 787-788. Special Tests; Orchil; Logwood; Tur- 
meric, 789. Caramel; Indigo, 790. Cochineal, 790. Mineral Pigments; 
Prussian Blue, 790. Ultramarine; Lead Chromate, 791. 

Coal-tar Colors, 791. Allowed Colors, 792. Detection in Food; Basic and 
Acid Dyes; Wool Dyeing, 793. Double Dyeing Method, 794. Vegetable 
Colors on Wool; Extraction of Colors by Immiscible Solvents, 795. Separa- 
tion with Ether, 796. Special Tests, 797. Classification and Identification 
of Coal-tar Dyes; Rota's Scheme, 797-802. Direct Identification of 
Colors, 803. Table of Reactions for Colors on the Fiber, 804-811. 
Reagents, 812. 

References on Colors, 813. 



TABLE OF CONTENTS. XVU 

CHAPTER XVIIl. 

PAGB 

Food Preservatives 815-841 

Preservation of Food, 815. Regulation of Antiseptics, 816. Commercial 
Food Preservatives, 817. Formaldehyde, 818. Determination in Preserva- 
tives, 819. Detection in Food, 820. Determination, 821. Boric Acid; Deter- 
mination in Preservatives, 821. Detection in Foods, 822. Determination, 
823-824. Salicylic Acid; Detection, 825. Determination, 826. Benzoic 
Acid, 827. Detection, 828-829. Determination, 830-833. Sulphurous Acid, 
833. Detection; Determination, 834. Fluorides, Fluosilicates, Fluoborates, 
835-836. Beta-Naphthol; Detection, 837. Asaprol or Abrastol, 837. 
References on Preservatives and their Use in Food, 838. 



CHAPTER XIX. 

Artificial Sweeteners 842-? 

E.xtent of Use; Saccharin, 842. Detection of Saccharin, 843. Determina- 
tion, 844. 

Dulcin; Detection, 845. Determination of Dulcin, 846. Glucin, 847. 
References on Artificial Sweeteners, 847. 



CHAPTER XX. 

Flavoring Extracts and their Substitutes 849-886 

Vanilla Extract, 849. Vanilla Bean, 849. Composition, 850. Vanillin; 
Exhausted Vanilla Bean; Composition of Vanilla Extract, 851. The Tonka 
Bean, 852, Coumarin; Adulteration of Vanilla Extract, 853. Artificial Ex- 
tracts, 854. Detection of Artificial Extracts, 855. Methods of Determining 
Vanillin, 856. Determination of Vanillin, Coumarin and Acetanilide, 858. 
Vanillin and Cumarin under the Microscope; Glycerin; Alcohol; Caramel, 
860. 

Lemon Extract, 861. Standards, 861. Adulteration, 862. Analytical 
Methods; Determination of Lemon Oil, 863-865. Alcohol, 866. Citral, 866. 
868. Methyl Alcohol; Colors, 869. Solids; Ash; Glycerin; Examination 
of Lemon Oil, 870. Constants of Lemon and other Essential Oils, 871. 
Citral, Citronellal, and other Adulterants, 872. Orange Extract, 873. 

Almond Extract, 873. Benzaldehyde; Standard, 874. Adulteration; 
Analytical Methods; Determination of Benzaldehyde, 875. Nitrobenzol; 
Distinction and Separation from Benzaldehyde, 876. Artificial Benzaldehyde; 
Alcohol; Hydrocyanic Acid, 877. Wintergreen Extract; Standards; Adultera- 
tion; Determination of Wintergreen Oil, 878. Peppermint Extract; Pepper- 
mint Oil; Standards, 879. Analytical Methods; Spearmint Extract, 880. 
Spice Extracts; Standards, 880; Analytical Methods, 881. Rose Extract; 
Standards, 882. Determination of Rose Oil; Imitation Fruit Flavors, 883. 
Determination of Esters, 884. Composition of Imitation Essences, 885. 

References on Flavoring Extracts, 886. 



xviii TABLE OF CONTENTS. 

CHAPTER XXi. 

pagb 

Canned and Bottled Vegetables, Relishes, and Fruit Products 887-929 

Canned Vegetables and Fruits, 887. Method of Canning, 888. Composi- 
tion, and Methods of Proximate Analysis, 889. Decomposition and Detection 
of Spoiled Cans, 890. Gases from Spoiled Cans, 891. Metallic Impurities, 
892. Action of Fruit Acids on Tin Plate, 893-896. Salts of Lead; 896. 
Salts of Zinc and Copper, 897-898. Greening of Copper Salts, 898. Salts of 
Nickel; Toxic Effects of Metallic Salts, 899. Separation and Determination 
of Metallic Salts, 899-903. Antiseptics in Canned Foods, 903. Detection of 
Preservatives, 904. Soaked Goods, 905. Ketchups and Table Sauces, 905. 
Composition, 906. Coloring, 907. Preservatives in Table Sauces, 908. 
Pickles and their Adulteration, 909. Horseradish, 910. 

Jams and Jellies, 909. Composition and Adulteration, 911-914. Adulter- 
ated Jams and Jellies, 914-915. Labeling "Compound" Goods, 915. 
Analytical Methods, 916. Determination of Sugars, 917-919. Glucose, 919. 
Dextrin; Tartaric Acid, 920. Coloring Matters, 921. Preservatives; Starch; 
Gelatin; Agar Agar, 922. Apple Pulp; Microscopical Examination, 923. 

Fruit Juices, 923-924. Grape Juice, 924. Sweet Cider; Lime Juice, 925. 
Fruit Syrups, 926. 

References on Canned Foods and Fruit Products, 927. 



PLATES I-XL. 

Photomicrographs of Pure and Adulterated Foods and of Aduterants 

Cereals: Barley, L Buckwheat, IL IH. Corn, HI, IV. Oat, IV. V. Rice, V, 
VI. Rye, VI, VII. Wheat, VIII. 

Legumes: Bean, IX. Lentil, IX, X. Pea, X. XI. 

Miscellaneous Starches: Potato; Arrowroot; Tapioca, XII. Turmeric; Sago, 
XIII. 

Coffee, XIV, XV. Chicory, XV. XVI. Cocoa, XVI, XVII. Tea, XVIII. 

Spices: Allspice, XVIII, XIX. Cassia, Cinnamon, XX-XXII. Cayenne, 
XXII XXIV. Cloves; Clove Stems, XXIV-XXVII. Ginger, XXVII-XXIX. Mace, 
XXIX. Nutmeg, XXX. Mustard, XXXI-XXXIII. Pepper, XXXIII-XXXVI. 

Spice Adulterants: Olive Stones; Cocoanut Shells, XXXVI. Elm Bark; 
Sawdust; Pine Wood, XXXVII. 

Edible Fats: Pure Butter; Renovated Butter; Olemargarine, XXXVIII. 
Lard Stearin, XXXIX. Beef Stearin, XL. 



FOOD INSPECTION AND ANALYSIS. 



CHAPTER I. 
FOOD ANALYSIS AND OFFICIAL CONTROL. 

INTRODUCTORY. 

The general subject of food analysis, in so far as the public health is 
concerned, is to be considered from two somewhat different standpoints: 
first, from the outlook of the government, state, or municipal analyst, whose 
mission it is to ascertain w^hether or not the food may properly be con- 
sidered pure or free from adulteration ; and second, from the point of view 
of the food economist, whose aim is to determine its actual composition 
and nutritive value. The one protects against fraud and injur)', the 
other furnishes data for the arrangement of dietaries and for an intelligent 
conception of the role which the various nutrients play in the metabolism 
of matter and energ}'^ in the body. The two fields are as a rule distinct each 
from the other, often involving, in the examination of the food, different 
methods of procedure. 

Official Control of Food. — In view of the importance of the consideration 
of food with reference to its purity, an ever-increasing number of states 
have realized the necessity of protecting their citizens from the unscrupu- 
lous manufacturers who in various lines are seeking to produce cheaper 
or inferior articles of food in close imitation of pure goods. Many of 
the states have laws in accordance with which the sale of such impure 
or adulterated foods is made a criminal offense, and some, but not all 
of these, are provided with public analysts and other officers to enforce 
these laws and punish the offenders. Numerous communities are awake 
to the importance of municipal control of such commonly used articles 
of food as milk, butter, and vinegar, and in many cases have machinery 
of their own for regulating the sale of these foods. 



2 FOOD INSPECTION AND ANALYSIS. 

Since January i, 1907, the federal government has been actively en- 
gaged in the enforcement of the national food law of June 30, 1906, through 
the Bureau of Chemistry of the U. S. Department of Agriculture. In 
addition to the central laboratories of this Bureau at Washington, upwards 
of 20 branch laboratories have been estabhshed in the principal cities of 
the United States to enforce the provisions of the national law which regu- 
lates interstate commerce in foods, as well as their manufacture and sale 
in the territories and the District of Columbia, and their importation from 
foreign countries. 

Food Analysis from the Dietetic Standpoint. — The study of the prin- 
ciples of dietetics has been given increased attention during the last decade 
in the curricula of many of the technical schools and colleges. Much 
has been accomplished by certain of the state experiment stations working 
as a rule in connection with the United States Department of Agriculture 
along this line. Investigations of this character are especially valuable, 
and are indeed rendered necessary by the general tendency of the modern 
physician to regard the hygienic treatment of disease, especially with 
reference to the matter of diet, as often of far greater importance than 
the mere administering of drugs. 

The food economist studies the varying conditions of age, sex, occupa- 
tion, environment, and health among his fellow men, with a view to show- 
ing what foods are best adapted to supply the special requirements of 
various classes. The quantity and proportion of protein, fat and carbo- 
hydrates, or of fuel value best suited for the daily consumption of a given 
class or individual having been determined, dietaries are made up from 
various food materials to supply the need with reference as far as possible 
to the taste and means of the consumer. 

Experiments are made on families, clubs, or individuals, representing 
various typical conditions of life, and extenchng over a given period, dur- 
ing which records are kept of the available food materials on hand and 
received during the term of the experiment, as well as of those remaining 
at the end. In the case of individuals, additional records may be kept 
of the amount and composition of tlie urine and feces. From such data 
the physiological chemist calculates the amount of nutrients utilized, 
and studies the metabolism of material in the human body. 

Up to this point no very extensive apparatus is required, but if in' 
addition the income and outgo of heat and energy are to be studied, which 
are important to a complete investigation of the economy of food in the 
body, the student will require a respiration cak)rimeter and its appurte- 



FOOD AN /I LYSIS AND STATE CONTROL 3 

nances. The calorimeter is so constructed that an individual may be 
confined therein for a term of days under close observation and with 
carefully regulated conditions. Such an equipment involves a large 
expenditure and is to be found in but few laboratories. 

It is not the purpose of the present w^ork to go beyond the strictly 
chemical or physical processes involved in making the analyses by which 
the proximate components of the foods are determined. For more com- 
plete information in the field of dietary studies and the metaboHsm of 
matter and energy in the body, the student is referred especially to the 
investigations of Atwater and his coworkers, as published in the annual 
reports of the Storrs Experiment Station at Middletown, and in the bulle- 
tins of the U. S. Department of Agriculture, Office of Experiment Stations, 
a list of which is given at the end of Chapter III. 

Commercial Food Analysis. — The proper preparation of food products 
has long ceased to be carried on by the hap-hazard rule-of-thumb methods 
that formerly prevailed. Now in the manufacture of many prepared foods 
and condiments, especially on a large scale, it has become a necessity to 
use scientific processes, rendered possible only by the employment of 
skilled chemists. In fact it is coming to be more and more common for 
food manufacturers to establish chemical laboratories in connection with 
their works, in the interests both of economy and of improved production. 

Frequently disputed points arise in the enforcement of the food laws 
that render the services of the private food analyst of great importance 
both to manufacturer and dealer. Thus a wide field is open to the analyst 
of foods outside the domain of the government or state laboratory, either 
in connection with the large food manufacturing plants directly, or in 
private laboratories for experimental research, or for analytical control 
work. 

SYSTEMATIC FOOD INSPECTION. 

Functions of the Oflficial Analyst. — The public analyst is employed by 
city, state, or government to pass judgment on various articles of food 
taken from the open market by purchase or seizure, either by himself or 
by duly authorized collectors employed for the purpose. The sole object 
of his examination is to ascertain whether or not such articles of food con- 
form to certain standards of purity fixed in some cases by special law, and 
in others by common usage or acceptance. Such a public analyst need not 
concern himself with the dietetic value of the food or whether it is of high 
or low grade. It is for him to determine simply whether it is genuine or 



4 FOOD INSPECTION AND ANALYSIS. 

adulterated within the meaning of the law, and, if adulterated, how and 
to what extent. Aside from his skill as a chemist, it is often necessary for 
him to possess other no less important qualifications, chief among which 
are his ability to testify clearly and concisely in the courts, and to meet at 
any time the most rigid kind of cross-examination, it being of the utmost 
importance that he understand thoroughly the nature of evidence. 

Standards of Purity for Food Products.* — Under an act of Congress 
approved March 3, 1903, standards of purity for certain articles of food 
have been established as official standards for the United States by the 
Secretary of Agriculture. The earlier of these standards were formulated 
under the Secretary's direction by a committee of the Association of Official 
Agricultural Chemists. Later, however, a joint committee of that asso- 
ciation and of the Association of State and National Food and Dairy 
Departments has had charge of this work. Standards have been and 
are being thus adopted, covering the entire range of food products. 

Nature of the Analytical Methods Employed. — Usually but a small 
percentage of the samples submitted for examination are actually adulter- 
ated. The analyst should, therefore, adopt for economy in time the 
quickest possible reliable processes for separating the pure from the 
impure, so that most of his attention may be devoted to the latter. 
The nature of the processes by which this is done varies with the foods. 
Experience soon enables one to judge much by even the characteristics of 
taste, appearance, and odor, though such superficial indications should be 
used with discretion. One or two simple chemical or physical tests may 
often suffice to establish beyond a doubt the purity of the sample, after 
which no further attention need be paid to it. 

A sample failing to conform to the tests of a genuine food must be 
carefully examined in detail for impurities or adulterants. While in 
most cases usage or experience suggests the forms of adulteration peculiar 
to various foods, the analyst should be on the alert to meet new conditions 
constantly arising. His methods are largely qualitative, since technically 
he need only show in most cases the mere presence of a forbidden 
ingredient, though for the analyst's own satisfaction he had best deter- 
mine the amount, at least approximately. 

In reporting approximate quantitative results in court, especially 
when they are calculated from assumed or variable factors, or when they 
are the result of judgment based on the appearance of the food under 

* V . S. Dept. of Agric, Off. of Sec;, Circ. 19. 



FOOD ANALYSIS AND STATE CONTROL. 5 

the microscope, the analyst should always be conservative in his figures 
by expressing the lowest or minimum amount of the adulterant, so as 
to give the defendant the benefit of any doubt. When exact standards 
are fixed by law, as in the case of total solids or fat in milk, for example, 
there is of course great necessity for preciseness in quantitative work. 

A full analysis of an adulterated food beyond establishing the nature 
and amount of the aduheration is entirely unnecessary, and in most 
instances adds nothing to the strength of a contested case, as twenty 
years' experience in the enforcement of the food laws in Massachusetts 
has shown. 

The responsibility resting upon the analyst is not to be lightly con- 
sidered, when it is realized that his judgment and findings constitute the 
basis on which court complaints are made, and the payment of a fine 
or even the imprisonment of the defendant may be the result of his report. 
Therefore he should be sure of his ground, knowing that his resuhs are 
open to question by the defendant. Where court procedure is apt to be 
involved, a safe nde is for the analyst to consider himself the hardest 
person to convince that his tests are unquestionable, making every possible 
confirmatory test to strengthen his position and consulting all available 
authorities before expressing his opinion; and finally, after being fully 
convinced that a sample is adulterated, and having so alleged, let him 
adhere to his statements and not waver in spite of the most rigid cross- 
examination to which he may be subjected. 

While each state or municipality has its own peculiar code of regula- 
tions and restrictions concerning the duties of the analyst and other officials, 
these rules are in the main very similar. For instance, it is usually neces- 
sary, excepting in the case of such a perishable food as milk, for the analyst 
to reserve a portion of a sample before beginning the analysis, which 
sample, in the event of proving to be adulterated, shall be sealed, so that 
in case a complaint is made against the vendor, the sealed sample may, 
on application, be delivered to the defendant or his attorney. 

Adulteration of Food. — Except in special cases a food in general is 
deemed to be adulterated if anything has been mixed with it to reduce 
or lower its quality or strength; or if anything inferior or cheaper has 
been substituted wholly or in part therefor; or if any valuable constituent 
has been abstracted wholly or in part from it ; or if it consists wholly or 
in part of a diseased, decomposed, or putrid animal or vegetable sub- 
stance; or if by coloring, coating, or otherwise it is made to appear of 
greater value than it really is; or if it contains any added poisonous 



6 FOOD INSPECTION AND ANALYSIS. 

ingredient. These provisions briefly expressed are typical of the general 
food laws adopted by most states and by the government, though the 
verbiage may differ. Laws covering compound foods and special foods 
vary widely with the locality. As to the character of adulteration, nine 
out of ten aduherated foods are so classed by reason of the addition of 
cheaper though harmless ingredients added for commercial profit, rather 
than by the addition of actually poisonous or injurious substances, though 
occasional instances of the latter are found. 

Authentic instances of actual danger to health from the presence of 
injurious ingredients are extremely rare, so that the question of food 
aduheration should logically be met largely on the ground of its fraudu- 
lent character. Indeed the commoner forms of adulteration are restricted 
to a comparatively small number of food products, the most staple articles 
of our food supply, such as sugar and the cereals, eggs, fresh meat, fresh 
vegetables and fruit being rarely subject to adulteration. 

Misbranding. — Under the federal food law and the laws of many of 
the states misbranding constitutes an offense as well as adulteration. By 
misbranding is meant any untrue or deceptive statement or design on the 
label of a food package, either regarding the nature of the contents, or of 
the place of manufacture or name of manufacturer. One of the com- 
monest forms of misbranding consists in the incorrect statement of weight 
or measure. Extravagant and untrue claims as to nutritive value have 
hitherto constituted a frequent form of misbranding. 

A Typical System of Food Inspection. — The efficiency of a system of 
public food inspection is greatly enhanced if the business part of the 
work, including the bookkeeping and attending to the outside public, 
be done wholly through some person other than the analyst, as, for example, 
a health officer, to whom the collectors of samples and the analyst 
may report independently as to the results of their work, and whose 
duty it is to determine what shall be done in cases of adulteration. 
In this way the analyst knows nothing of the data of collection 
nor the name of the person from whom the sample was purchased, 
so that he can truthfully state in court that his analysis was un- 
biased. 

Suppose, for example, that three collectors are employed to purchase 
samples of food for analysis, their duties being to visit at irregular intervals 
different portions of a state or municipality. Each collector keeps a book 
in which he enters all data as to the collection of the sample, includ- 



FOOD ANALYSIS AND STATE CONTROL. 




Fig. I. — Inspectors' Lockers. Insuring safe legal delivery of samples collected by tiiree 
inspectors. Each locker has a door in the rear accessible, from an anteroom, to the in- 
spector holding key to that locker only. 



FOOD INSPECTION AND ANALYSIS. 




Fig. 2. — Inspectors' Lockers. Front View. The lockers are accessible to the analyst in the 
laboratory by a single sliding-sash front, provided with a spring lock. The removable 
sliding-racks are convenient for returning clean sample bottles. 



FOOD /ANALYSIS AND STATE CONTROL. 9 

ing the name of the vendor, assigning a number to each sample, which 
number is the only distinguishing mark for the analyst. One collector 
may use for this purpose the odd numbers in succession from i to 9999, 
the second the even numbers from 2 to 10,000, while the third may use 
the numbers from 10,000 up. Each of the two former would begin with a 
lettered series, as, for instance. A, numbering his samples i A, 3 A, 5 A, 7 A, 
etc., or 2A, 4A, 6A, etc., till he reached 10,000, then beginning on series 
B and so on. If the analyst is to be kept in ignorance of the brand or 
manufacturer in the case of package goods, the collector must remove 
from the original package sufficient of the sample for the needs of the 
analyst, and deliver it to the latter in a plain package, bearing simply the 
name under which the article was sold and the number. Such precau- 
tions are, however, not always practicable and depend largely on local 
regulations. The analyst reports the result of the analysis of each sample 
with the number thereof on a librar}' card, with appropriate blanks both 
for data of analysis and for data of collection, the latter to be filled by 
the collector from his book after the analyst has handed in the card with 
the data of analysis. This system of recording and reporting analyses 
has been successfully used for years by the Department of Food and 
Drug Inspection of the Massachusetts State Board of Health. 

Legal Precautions. — The laborator}^ of the pubhc analyst should 
preferably be provided with a locker for each collector, to which access 
may be had only by that collector and the analyst, so that in the absence 
of the latter, or when circumstances are such that the samples cannot be 
dehvered to him personally, there may be such safeguards with respect 
to lock and key as to leave no question in the courts as to safe deHvery 
and freedom from accidental tampering. With such a system it is un- 
necessary for the collector to place under seal the various samples sub- 
mitted for analysis. Unless such lockers or their equivalent are employed, 
it is best to carefully seal all samples. 

Such a system of lockers for use with three collectors is shown in 
Figs. I and 2. The same careful attention should afterwards be given to 
keep the specimens in a secure place both before and during the process 
of analvsis, and to label with care all precipitates, filtrates, and solutions 
having tr do with the samples, especially when several processes are 
being simultaneously conducted, in order that there may be no doubt 
whatever as to their identity. The importance of precautions of this 
kind in connection with court work can hardly be too strongly emphasized. 



lo FOOD INSPECTION ^ND /IN A LYSIS. 

Practical Enforcement of the Food Law. — In the case of foods actually 
found adulterated, there are three practical methods of suppressing their 
further sale, viz., by pubhcation, by notification, and by prosecution. These 
may be separately employed or used in connection with each other, accord- 
ing to the powers conferred by law on the commission, board, or official 
having in charge the enforcement of the law, and according to the dis- 
cretion of such official. 

Publication. — Under the laws of some states, the only means of pro- 
tecting the people lies in publishing lists of adulterated foods with their 
brands and manufacturers' names and addresses in periodical bulletins 
or reports. Sometimes it is considered best to publish for the informa- 
tion of the pubhc lists of unadulterated brands as well, and, again, it is 
held that only the offenders should thus be advertised. 

Such pubhcation, by keeping the trade informed of the blacklisted 
brands and manufacturers, certainly has a decidedly beneficial effect 
in reducing adulteration, and involves less trouble and expense than 
any other method. It is obviously an advantage, however, in addition 
to this to be able in certain extreme cases to use more stringent methods 
when necessary. 

Notification and Prosecution.— The adulteration of food is best held 
in check in locaUties where under the law cases may be brought in court 
and are occasionally so brought. The mere power to prosecute is in 
itself a safeguard, even though that power is not frequently exercised. 
Under a conservative enforcement of the law, actual prosecution should 
be made as a last resort. Neither the number of court cases brought 
by a food commission nor the large ratio of court cases to samples found 
adulterated are criteria of its good work. Except in extreme cases, 
it is frequently found far more effective to notify a violator of the law, 
especially if it is a first offense, giving warning that subsequent infraction 
will be followed by prosecution. Such a notification frequently serves 
to stop all further trouble at once and with the minimum of expense. 
Instances are frequent in Massachusetts where, by such simple notifica- 
tion, widely distributed brands of adulterated foods have been immediately 
withdrawn from sale. 

Massachusetts was the first of all the states to enact pure-food legisla- 
tion, and for twenty-five years has had a well-establislied system of 
inspection, prosecuting cases under its laws through the Food and Drug 
Department of the State Board of Health. Cases are brought in court 
with practically no expense for legal services. Complaints are entered by 



FOOD AN /{LYSIS AND STATE CONTROL. ii 

the collector, or, as he is termed, inspector, who makes complaint not in 
his official capacity, but as a citizen who under the law has been sold a 
food found to be adulterated, and who is entitled to conduct his own 
case, which he does with the aid of the analyst and such other witnesses 
as he may see fit to employ. Experience is readily acquired by the inspector 
in conducting such cases in the lower pohce or municipal courts, where 
they are first tried, and years ago the services of legal counsel in Massa 
chusetts were dispensed wdth as superfluous.* 

Statistics in the annual reports of the Massachusetts Board show with 
what uniform success these trials have been conducted. While more 
often settled in the lower courts, occasional appeal cases are carried tc 
the superior courts, where the services of the regular district attorney are 
■of course availed of in prosecuting the case. 

Such a system as the above, while admirable for a state or city after 
long experience in the enforcement of food laws in the courts, is obviously 
impracticable with newly established systems of state food inspection. 

REFERENCES ON FOOD INSPECTION AND STATE CONTROL. 

Abbott, S. W. Food and Drug Inspection. Article in Reference Handbook of the 
Medical Sciences, Vol. 3, pp. 162-180. N. Y., 1902. 

Andrews, O. W. Public Health Laboratory Work and Food Inspection. London, 
1901. 

BiGELOW, W. D. Foods and Food Control. U. S. Dept. of Agric, Bur. of Chem., Bui. 
69, rev. 

• Food Legislation for the Year Ending June 30, 1907. Ibid., Bui. 112. 

Pure Food Laws of European Countries. U. S. Dept. of Agric, Bur. of Chem., 

Bui. 61. 

BucHKA, K. VON. Die Nahrungsmittelgesetzgebung im Deutschen Reiche. Berlin, 
1901. 

Chapin, C. V. Municipal Sanitation in the United States. Providence. 

Kenwood, H. R. Public Health Laboratory Work. London, 1904. 

LE.A.CH, A. E. Character and Extent of Food and Drug Adulteration in Massachu- 
setts and the System of Inspection of the State Board of Health. Tech. Quar- 
terly, March, 1900. 

Moor, C. D. Suggested Standards of Purity for Foods and Drugs. London, 1902. 

Neufeldt, C. a. Der Nahrungsmittelchemiker als Sachverstandiger. Berlin, 1907. 

* Where such a practice is in vogue an intelligent inspector must of course be chosen 
with reference to his ability to do this court work. The food laws are few and simple, as 
are also the court decisions rendered under them, so that it is no great task for the inspector 
to become much more familiar with them than the average general lawyer whom he meets 
in court and who not infrequently consults the inspector for information regarding these laws. 



12 FOOD INSPECTION AND AN/t LYSIS. 

PoLiN ET Labit. Examen des Aliments suspects. Paris, 1892. 

Tucker, W. G. Food Adulteration: Its Nature and Extent and How to Deal with 

It. Med. Rev. of Rev's, Oct., 1903. 
Vacher, F. The Food Inspector's Handbook. London, 1893. 
Wedderburn, a. J. Reports on Extent and Character of Food and Drug Adulteratiort 

in the United States. U. S. Dept. of Agriculture, Div. of Chem., Bulletins 25^ 

32, and 41. 
Wiley, H. W. Foods and Their Adulteration. Philadelphia, 1907. 
WiJRZBURG, A. Die Nahrungsmittelgesetzgebung im Deutschen Reiche. Leipzig,, 

1903. 
The British Food Journal, London, 1899 et seq. 

Food and Sanitation, London, 1892-1900 (discontinued August, 1900). 
Journal of the Sanitary Institute, 1892 et seq. 
Revue International des Falsifications, Amsterdam, 1888 rt seq. 
The American Food Journal, Chicago, 1906 et seq. 
The Food Law Bulletin, Chicago, 1907 et seq. 

Biennial Reports of the Idaho Dairy, Food and Oil Commission, 1903 et seq. 
Veroffentlichungen des kaiserlichen Gesundheitsamtes. Berlin, 1877 et seq. 
Arbeiten aus dem kaiseslichen Gesundheitsamtes. Berlin, 1886 et seq. 
Reports of the Local Government Board of England, 1877 et seq. 
Reports of the Paris Municipal Laboratory, 1882 and 1885. 
Reports of the Canton Chemists of Switzerland, 1890 et seq. 
Annual Reports of the Massachusetts State Board of Health, 1883 et seq. 
Monthly Bulletins of the Massachusetts State Board of Health. 
Annual Reports of the Conn. Agric. Exp. Station on Food Products, 1896 et seq. 
Annual Reports of the Ohio Dairy and Food Commissioner, 1890 et seq. 
Annual Reports of the New Jersey Dairy Commissioner, 1886 et seq. 
Annual Reports of New Jersey Laboratory of Hygiene, Chemical Dept., 1903 et seq. 
Annual Reports of the Michigan Dairy and Food Department, 1893 et seq. 
Monthly Bulletins of the Michigan Dairy and Food Department, Aug., 1895 et seq. 
Biennial Reports of the Minnesota Dairy and Food Commissioner. 
Annual Reports of the Wisconsin Dairy and Food Commissioner, 1890 et seq. 
Annual Reports of the Penn. Board of Agriculture, 1894 et seq. 
Annual Reports of the Illinois State Food Commissioner, 1899 et seq. 
Biennial Reports of the New Hampshire State Board of Health, 1902 et seq. 
Quarterly Bulletins of the New Hampshire State Board of Health, 1902 et seq. 
Annual Reports of the North CaroHna Slate Board of Agriculture on Food Products, 

1900 et seq. 
Bulletins of the North Dakota Experiment Station. 
Annual Reports and Monthly Bulletin of the Indiana State Board of Health, 1905, 

et seq. 
Official Inspections of the Maine Agricultural Experiment Station. 



FOOD ANALYSIS AND STATE CONTROL 13 

Annual Reports of the Wyoming State Dairy Food and Oil Commission, 1904 et seq. 
Quarterly Bulletins of the Vermont State Board of Health. 
Annual Reports of the South Dakota Food and Dairy Commission, 1901 et seq. 
Proceedings and Methods of Analysis of the Association of Official Agricultural 

Chemists, published as bulletins of the U. S. Department of Agriculture, Bureau 

of Chemistry. 
Proceedings of the National Association of State Dairy and Food Departments, 1902 

et seq. 



CHAPTER II. 
THE LABORATORY AND ITS EQUIPMENT. 

Location. — The selection of a location for a food laboratory cannot 
always be made solely with reference to its needs and its convenience, 
but it is more often subject to economic conditions beyond the analyst's 
control. Under very best conditions, such a laboratory should be situated 
in a building designed from the start exclusively for chemical or biological 
and chemical work. Almost any well-lighted rooms in such a building 
can be readily adapted for the purpose. When, however, as is frequently 
the case, rooms for such a laboratory are provided in municipal, govern- 
ment, or office buildings, in which for the most part clerical work is done, 
the problern of adequately utilizing such rooms so that they may not 
at the same time prove offensive to or interfere with the comfort of other 
occupants of the building is sometimes difficult. It is obvious that base- 
ment rooms in such a building, as far as ventilation is concerned, are less 
readily adapted for the requirements in hand than are those of the top 
floor, though, if the light is good and there are abundant and well-arranged 
ventilating-shafts, such rooms may be made to serve every purpose. In 
the basement one may most easily obtain water, gas, and steam, and 
dispose of wastes without annoyance to one's neighbors. When, how- 
ever, it is possible to do so, rooms on the top floor of an office building 
should be utilized for a food laboratory, for in such rooms the problems 
of lighting, heating and ventilating are comparatively simple and may 
usually be solved without regard to other occupants. In such a case 
ample provision must be made, preferably through shafts which are 
readily accessible for water-, gas-, steam-, and soil-pipes passing down 
below. 

The actual equipment of the food laboratory depends of course largely 
on its particular purpose; and while it is manifestly impossible to do other- 
wise than leave the details to the individual taste and needs of the analyst, 

14 



THE LABOR/iTORY AND ITS EQUIPMENT. 15 

modified by the means at his disposal, a few general suggestions regarding 
important essentials may prove helpful. These imply a fairly liberal 
though not extravagant outlay, with a view to saving both time and energy 
by convenient surroundings well adapted to the work in hand. At the 
same time equally satisfactory work is possible under simpler conditions 
than those described. 

Floor. — The best material for the floor of the working laboratory 
is asphalt. Such a floor is firm but elastic, is readily washed by direct 
appHcation of running water, if necessary, and resists well the action of 
ordinary reagents. An occasional thin coating of shellac with lampblack 
applied with a brush gives the asphalt floor a smooth, hard surface and 
may be applied locally to cover spots and blemishes. 

Lighting. — The lighting of the rooms, if on the top floor, is best effected 
by both wall windows and skylights. North windows furnish the best 
light for the microscope; the skylight, when available, is the ideal hght 
for the balance and for general laboratory work. 

Ventilation by forced draft is a great convenience. For this purpose 
an exhaust-fan driven by an electric motor and controlled in speed by 
a fractional rheostat is admirable. Such a fan had best be located in a 
small closed compartment or closet near the centre of the series of rooms 
designed to be ventilated by it, and this closet should have directly over the 
fan an outlet-shaft passing through the roof of the building. With such 
a system, a series of branching air-ducts should radiate from the fan closet, 
conveniently arranged either above or along the ceiling and communicat- 
ing with the various hoods, closets, and rooms near the top. 

Benches. — The working benches should have wooden or glazed tile 
tops. White glazed tile, if properly laid, furnish a very clean, sanitary, 
and resistant surface, besides being often convenient for color tests. If 
laid on a plank surface, cement should not be applied directly, as it swells 
the wood before drying out and results in a loose and often uneven surface. 
Cement may be avoided altogether and the tiles after first soaking in oil may 
be laid in putty directly on the wood. Tiles may be laid in cement by first 
covering the plank surface with cheap tin plate, overlapping the edges and 
securing by tacks. This prevents swelhng of the wood. The tin may be 
covered to advantage with cheap paint. The tiles may then be embedded 
in a layer of cement spread over the tin surface. 

Soft encaustic glazed tiles commonly used for wall finish are not as 



l6 FOOD INSPECTION AND ANALYSIS. 

effective as hard floor tiles, since the former crackle and lose color when 
subjected to heat. If the hard floor tiles can be specially glazed, they make 
by far the most satisfactory and enduring surface. 

When wooden bench tops are used they may be treated to advantage 
by staining with the following solutions: 

Solution \. ICO grams of anilin hydrochloride, 40 grams of ammonium 
chloride, 650 grams of water. 

Solution 2. 100 grams of copper sulphate, 50 grams of potassium 
chlorate, 615 grams of water. 

Apply solution i thoroughly to the bare wood and allow it to dry; then 
apply 2 and dry. Rcj)eat these ap])lications several times. Wash with 
plenty of hot soap solution, let dry and rub well with vaseline. It is claimed 
that wood so treated is rendered fire-proof and is not acted on by acids and 
alkalies. When the tinish begins to wear, an application of hot soap solu- 
tion or vaseline will bring back the deep black color. 

The benches shoukl naturally be located with reference to best light 
from skylights or windows. Gas and water outlets, sinks and waste-pipes I 
should be conveniently arranged with reference to the working benches, as 
well as suitable provisions for air-blast and exhaust, while in the space be- 
neath the benches such drawers, cupboards, and receptacles as are required 
should be provided. A clear bench width of 24 inches is ample for most 
work; if wider there is a temptation to allow apparatus to accumulate at the 
back. At the back of the bench and within easy reach, a raised narrow 
shelf should be provided to be used exclusively for common desk reagents. 
This again should not be so wide as to allow the accumulation of useless 
bottles. A narrow raised guard or beading at the edge of the reagent shelf 
prevents the bottles from accidently slipping off. 

Hoods. — Closed hoods with sliding sash fronts are almost indispensable. 
These hoods should be directly connected with the ventilating shafts or 
pipes, or with the air-ducts that radiate from the exhaust-fan closet, when 
such a system is provided. Gas outlets inside the hoods are neces- 
sary. 

When there is a good draft, either natural or forced, a hooded top 
over the working bench, such as that shown in Fig. 3, is quite as efficient 
as a closed hood for most purposes. This is best made of galvanized 
iron, painted on the outside and treated on the inside with a preparation 
of graphite ground in oil. Here are best carried out all the processes 
involving the giving off of fumes and gases, which, if the ventilation is 
efficient, should pass directly up the flues and not come out in the room. 



THE L^BOR/tTORY AND ITS EQUIPMENT. 



17 



Sinks and Drains.— The sinks should preferably be of iron or porce- 
lain. If iron, they should at frequent intervals be treated with a coat of 




Fig. 3. — Hooded Top of Galvanized Iron over Working-bench, Connected with 
\'entilating Air-ducts. 

■asphalt varnish. A great convenience is a hooded sink (Fig. 4) in which 
foul-smelling bottles, or vessels giving off noxious or offensive fumes 



i8 



FOOD INSPECTION AND ANALYSIS. 



or gases, may be rinsed under the tap while completely closed in. Open- 
work rubber mats at the bottom of the sinks help to insure against break- 
age. Open plumbing of simplest design should be used, and a multi- 
plicity of traps should be avoided. Sinks may be variously located for 




Fig. 4. — A Hooded Sink. An injector-like arrangement of steam and cold-water pipes 
furnishes water of any desired temperature. 

convenience without regard to situation of soil-pipes, if the floor is thick 
enough to allow an open drain with sufficient pitch to flow readily. Such 
open drains are much more readily cleaned than closed pipes, and are 
best constructed by splitting a lead pipe and laying it in an iron box which 
is sunk into the floor. The edges of the lead pipe are rounded over those 
of the box as in Fig. 5, fiUing the joints with hydraulic cement, and 
the top of the drain is covered by a series of readily removable iron plates 



I 



THE LABORATORY AND ITS EQUIPMENT. 



19 



flush with the top of the floor. Waste-pipes from sinks, still-condensers, 
refrigerators, and various forms of apparatus involving flowing water may 
be led into this drain, holes being drilled in the iron cover for their insertion. 
Steam and Electricity. — These are useful but not indispensable. Steam, 
when available, may be used to advantage for boiling ether or benzine 
in connection with continuous fat-extraction apparatus, for furnishing 
the motive power for driving the Babcock centrifuge, for heating water- 
baths and hot closets, and, in connection with cold water, to furnish a 




Fig. 5. — Section of Open Drain-pipe in Floor. 

supply of hot water when wanted at the sink. The latter application 
is illustrated in Fig. 4. 

If electricity is used for lighting, it may also be applied in a variety 
of useful ways in the laborator}^ as, for instance, for heating coils or electric 
stoves, for electrolysis, and for running small motors, which in turn may 
be employed for driving centrifuges, shaking apparatus, ventilating- fans, 
air-pumps, etc. 

Suction and Blast. — If the water-pressure is ample, both air-pressure 
and exhaust for blast-lamps, vacuum filtration, and other purposes are 
readily available through the agency of the various devices used in con- 
nection ^N^ith the flow of water, as, for instance, the Richards pump. When, 
however, the water pressure is insufl&cient, other means must be employed 
for furnishing these much-needed requisites. Fig. 6 illustrates a simple 
and almost noiseless pressure and exhaust pump run by a i-H.P. electric 
motor, which with the pressure-equalizing tank and the appropriate 
coimections are mounted on a light wheel truck, and readily movable 
to any part of the laborator}-. By simply scre\\'ing the plug into an 



20 



FOOD INSPECTION AND /IN/1 LYSIS. 



electric-light outlet, either suction or blast may be had at will, depending 
on the position of a knife-edge switch which determines the direction of 
the current. By means of a fractional rheostat the speed may be varied 
and the pressure thus controlled. 




Fig. 6. — Portable Pressure- and Exhaust-pump Run by Electric Motor, 
lamps, vacuum filtration, etc. 



Useful for blast- 



APPARATUS. 



The laboratory is of course to be supplied with the usual assortment 
of test-tubes, flasks, beakers, evaporating and other dishes of porcelain, 
platinum and glass, funnels, casseroles, crucibles, mortars, burettes, 
pipettes, graduates, rubber and glass tubing, lamps, ring-stands and 
various supports, clamps and holders, the nature, number, and sizes of 
which are determined by individual requirements. Special forms of 
apparatus peculiar to certain processes of analysis or to the examination 
of special foods will be described in their appropriate connection. The 
following apparatus of a general nature may be regarded as indispensable 
for the proper fitting out of the food laboratory: 

Balances. — These should include (i) an open pan balance for coarse 
weighing, having a capacity up to i kilogram and sensitive to o.i gram, 
with a set of weights; and (2) an analytical balance, enclosed in a case, 
sensitive to .0001 gram under a load of 100 grams, with an accurate set 
of non-corrosive weights. The short-beam analytical balance is prefer- 



i 



THE LABORATORY AND ITS EQUIPMENT. 



21 



able for quick work, and as constructed by the best modem makers leaves 
nothing to be desired. 

The Water-hath. — This is such an important accessory to the food 
analyst that it should, if possible, be specially designed to meet his require- 




FiG. 7- — ^Water-bath, Enclosed in Hood, with Sliding-sash Front. 

ments, though the ordinan' copper baths, supported on legs and designed 
to be heated by gas-burners, as kept in regular stock by the dealers, will 
sometimes sen-e the purpose. For nearly all moisture dete rm inations the 
platinum dishes described on page 133 and the somewhat larger wine-shells 
of 100 cc. capacity are most used, and for this purpose the top of the 
bath should have plenty of openings of the right size for these. A very 
economical construction of bath admirably adapted for the food analyst's 
use is sho'iATi in plan in Fig. 8, being the form employed by the writer. 



FOOD INSPECTION AND ANALYSIS. 



The size and number of openings are determined by the number of 
samples to be simultaneously analyzed. The dotted lines indicate a steam- 
coil within the body of the bath, which serves to boil the water. Fig. 7 
shows the bath in place within a hood, the sliding front of which is fur- 
nished with a hasp and padlock, so that it may always be kept locked by 
the analyst whenever he is temporarily absent from the laboratory. This 
is a useful precaution, when the residues left thereon are from samples 
which are to form subjects for possible prosecution in court later. 



s'c; 




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Fig. 8. — Plan View of Water-bath Boiled by Steam-coil. W and TI'' are water inlet and 
outlet, S and S' steam inlet and outlet, respectively. 

Steam, if available at all seasons of the year, furnishes a ready means 
of heating the bath. Electric immersion coils are also convenient. In the 
absence of both steam and electricity, the bath must be boiled by gas- 
burners. 

The Drying-oven. — A convenient form of asbestos-covered, jacketed 
air-oven, having removable shelves and heated by a gas-burner is shown in 
Fig. 9, with an efficient form of gas-pressure regulator. The particular 
form of low burner best adapted for use with the oven is also shown. Such 
an oven may also be heated by an electric coil, the temperature being 
governed by a rheostat of delicate construction. 

The Water-still. — An efficient still should be provided, capable of 
supplying the laborator)^ with an ample quantity of pure water for analyti- 
cal purposes. Fig. 10 illustrates a compact form of still, which is particu- 
larly economical in view of the fact that a single stream of inflowing cold 



THE LABORATORY AND ITS EQUIPMENT. 23 

water first serves to cool the condenser, and, rising, becomes vaporized 
in the boiler directly connected with the condenser at the top. This 
apparatus is capable of distilling six gallons of water in twelve hours. 




Fig. 9. — Asbestos-covered Air-oven, with Gas-pressure Regulator. 



The list of indispensable requisites in addition to the above should 
include the following: 

Continuous Extraction Apparatus (Figs. 18, 19, and 20). 

Apparatus for Nitrogen Determination (Figs. 24, 25, and 26). 

Apparatus for Distilling Various Food Products (pp. 71 and 660). 

A Babcock or other Milk-fat Centrifuge (Figs. 11, 44, and 45). 

A Butyro Refractometer (Fig. 36). 

An Immersion Refractometer (Fig. 40). 

A Microscope and its A ppurtenances (Chapter V) . 

A Polariscope and its Accessories (Figs. 102, 103, and 104). 

Apparatus for Specific Gravity Determination (Figs. 14, 15, 16 and 17). 

Apparatus for the Determination of Carbon Dioxide (Fig. 71). 

Apparatus for the Determination of Melting-points (Fig. 93). 

Marsh Arsenic Apparatus (Fig. 27). 

Electrolytic Apparatus (Fig. no). 

Separatory Funnels (Figs. 22 and 23). 

Following is a list of apparatus and appliances which, while not indis- 
pensable, are convenient and at times desirable : 



24 FOOD INSPECTION AND y4NALYSIS. 

A Spectroscope^ either of the direct-vision variety for the pocket, or 
the Kirschoff & Bunsen style on a stand. 

Spectroscope Cells, parallel-sided, for observation of absorption spectra^ 
A Photomicrographic Camera and Appurtenances^ (pp. 96 to 98). 
A Muffle Furnace, 




Fig. 10. — A Convenient Laboratory Water-still with Earthenware Receptacle, Provided with 

Faucet and Glass Gauge. 

An Incinerator for a Large Number of Residues (Fig. ^^3). 

An Ebullioscope (Fig. 113). 

An Assay Balance, for weighing arsenic mirrors to o.oi mg. 

An Abbe Refractometer (Fig. 39). 

A Schreiner Colorimeter (Fig. 28). 

A Lovibond Tintometer (p. 78). 

* A photographic dark room is also necessary if photomicrographic work is to be done* 



THE LABORATORY AND ITS EQUIPMENT. 



2S 



A Universal Centrifuge. — This convenient apparatus merits a separate 
brief description, being useful for a wide variety of purposes, such as 
breaking up ether- and other emulsions, quickly settling out precipitates, 
and roughly estimating chlorides, sulphates, phosphates, etc., by the 
volume of the precipitate in graduated tubes. Various-sized aluminum 
frames, carrying hinged shields, are interchangeably adjustable to the 




Fig. II. — The Universal Centrifuge. Driven by an electric motor. 

spindle of a vertical electric motor.* The smallest frame has shields 
adapted to hold two graduated glass tubes of 15 cc. capacity (see Fig. 11). 
This is for the quantitative estimation of small precipitates and the quick 
settling of sediments. A medium-sized and large .frame carr}^ tubes of 
80 cc. an.d 120 cc. capacity respectively. A frame is also provided 
with shields adapted for various-sized beakers to be used in settling pre- 
cipitates. The milk-fat centrifuge frame shown in Fig. 45 is alsa 
adapted to be used on the spindle of the same motor. 

* In the absence of electricity a water-motor may be used. 



26 



FOOD INSPECTION ^ND /iNALYSIS. 



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FOOD INSPECTION AND ANALYSIS. 



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THE LABORATORY AND ITS EQUIPMENT, 



35 



REAGENTS. 

The foregoing list includes the general reagents used in carrying 
out the processes treated of in this volume, together with their strength, 
mode of preparation when necessary, and other data. 
Reagents, especially those constantly employed, should 
be assigned to regular places on the shelves, and 
should invariably be kept in place when not in use. 

Among the standard solutions for volumetric work, 
none is more frequently of service in the food labora- 
tory than a tenth-normal solution of sodium hydrox- 
ide, and a large supply of this reagent, carefully 
standardized, should be at all times conveniently at 
hand. Besides being useful for standardizing tenth- 
normal solutions, it is constantly needed for deter- 
mining various acids in food products, such as milk, 
vinegar, butter, Hme juice, cream of tartar, liquors, 
and many others. Time is well spent in carefully ad- 
justing this solution to its exact tenth-normal value, 
thus simpHfying the calculation of results. A large 
stock bottle (say of two gallons capacity) containing 
the standard tenth-normal sodium hydroxide, is con- 
veniently mounted with a side-tube burette in con- 
nection, in some such manner as shown in Fig. 12, A 
small connecting side bottle contains a strong solution 
of sodium hydroxide (reagent No. 240) through which 
the air that enters the large bottle is passed, thus depriving it of CO2. 
In this manner the standard solution may readily be kept of unvaiying 
strength for a year or more. 




Fig. 12.— Stock Bot- 
tle of Tenth-normal 
Alkali. 



36 FOOD INSPECTION /IND /1N/1 LYSIS. 



EQUIVALENTS OF STANDARD SOLUTIONS. 

No. 31. Decinormal Sulphuric Acid. One cc. is equivalent to 

Ammonia gas NH3 0.0017 gram 

Ammonia NH.OH 0.0035 

Ammonium carbonate (NH JoCOg o . 0046 

(NH^^^CA^HoO 0.0057 

Calcium carbonate CaCOj 0.0050 

Calcium hydroxide Ca(OH)o 0.0037 

" o.xide CaO 0.0028 

Lead acetate Pb(C2H30,)2,3H20 0.0189 

Magnesia MgO 0.0020 

Magnesium carbonate MgCOg 0.0042 

Nitrogen N 0.0014 

Potassium acetate * KC2H3O2 o . 0098 

" bicarbonate KHCO3 o.oioo 

" bitartrate * KHC.HPg 0.0188 

" carbonate K2CO3 0.0069 

" citrate* K3C8Hj07,H20 0.0106 

" hydroxide KOH 0.0056 

" and sodium tartrate . KNaC^H^O(„4H20 0.0141 

Sodium acetate NaC2H302,3H20 0.0136 

" benzoate * NaCjH^O, 0.0144 

" bicarbonate NaHC03 0.0084 

" borate Na2B,07,ioH20 0.0191 

" carbonate Na2C03 0.0053 

Na2C03,ioH20 0.0143 

' ' hydroxide NaOH o . 0040 

" salicylate* NaCyHjO^ 0.0160 

No. 241. Decinormal Sodium Hydroxide Solution. One cc. is equivalent to 

Acid, acetic H,C2H302 0.0060 gram. 

' * boric H3BO3 o . 0062 

" citric H3C6H,0„H20 0.0070 

" hydrobromic HBBr 0.0081 

" hydrochloric HCl 0.00365 

" hydriodic HI ^ 0.0128 

" lactic HC3H,03 0.0090 

" malic C^HjO^ 0.0067 

" nitric HNO3 0.0063 

" cxalic H2C20,,2H20 0.0063 

,, , , . XT T,r^ ^ to form K2HPO,with ( 

phosphoric U,VO,^ phenolphthalein f°-°°^9 

., , , . .X T.^ ^ to form KHoPO.with / 

' phosphoric H3FO, 1 , , " .0.0098 

' '^ ■* M methyl orange ) 

' ' sulphuric HjSO^ o . 0049 

" tartaric H2C^H^Oj 0.0075 

Potassium bitartrate KHC^H^Op 0.0188 

Sodium borate NugB^O^jioHgO 0.00955 



* To be ignited. 



THE LABORATORY AND ITS EQ^JfPMENT. 37 

No. 142. Decinormai, Iodine Solution. One cc. is eiiuivalent to 

Ars3niou5 oxide ASjOg o.oo\g^ gram. 

Potassium sulphite K2S03,2H20 0.0097 

Sodium bisulphite NaHS03 0.0052 

sulphite, Na2S03,7H20 0.0126 

" thiosulphate Na2S203,5H20 0.0248 

Sulphur dioxide SO, 0.0032 

Sulphurous acid H0SO3 0.0041 

No. 245. Decinorm.\l Sodium Thiosulphate Solution. One cc. is equivalent to 

Bromine Br o . 0080 gram. 

Chlorine CI 0.00355 " 

Iodine 1 0.01266 " 

Iron (in ferric salts) Fe 0.0056 " 

No. 230. Decinormal Silver Nitrate Solution.* One cc. is equivalent to 

Ammonium bromide NH^Br 0.0098 gram. 

' ' chloride NH^Cl 0.00535,. " 

Chlorine CI 0.00355 " 

Cyanogen (CN)2 0.0052 " 

Hydrocyanic acid HCN with indicator 0.0027 " 

,. ,, rT^»T ( to formation of precip- ) 

HCN' f 0.0054 

( itate ' ^^ 

Hydrobromic acid HBr 0.0080 " 

Potassium bromide KBr 0.0119 " 

" chloride KCl 0.00745 " 

" cyanide KCN with indicator 0.0065 " 

,, ,, ( to formation of precip- J ,, 

KCN- . ^ '. o.oi^o 

( itate ) -^ 

Sodium bromide NaBr 0.0103 " 

' ' chloride NaCl 0.00585 ' * 

No. 201. Decinormal Potassium Bichromate Solution.! One cc. is equivalent to 

Ferrous carbonate FeCOj o.oi 16 gram. 

Ferric oxide FC2O3 0.0080 " 

Fen-ous oxide FeO 0.0072 ' ' 

" sulphate FeSO^ 0.0152 " 

FeSO^,7H20 0.0278 " 

Iron (ferrous) Fe 0.0056 " 

No. 220. Decinormal Potassium Permangan.a.te Solution. One cc. is equivalent to 

O.xalic acid HjCgO^, 2H2O o. 0063 gram, 

and to same weights for iron salts as given under N/io KjCrjO,. 



* Use potassium chromate solution as an indicator, or add till precipitate appears. 

t Use a freshly prepared solution of potassium ferricyanide as an indicator, applying a drop of titrated solu- 
tion to a drop of indicator un a white surface. 



38 



FOOD INSPECTION /1ND /ANALYSIS. 



The following table from Talbot * shows the reactions of the com- 
mon indicators used in acidimetr}': 



Indicator. 



Reaction with 
Acids. 



Reaction 

with 
Alkalies. 



Use with 
Carbonic 
Acid in Cold 
' Solution. 



Use with 

Carbonic 

Acid in Hot 

Solution. 



Use with TT ... 

Ammonium nr^'l^'l'^M 
Salts. I Oi^ganic Acid. 



Litmus 

Methyl orange. 
Phenolphthalein 

Lacmoid 

Cochineal 

Rosolic acid 

Alizarine 



Red 

Pink 

Colorless 

Purple-red 

Pur[)le-red 

Yellow 

Yellow 



Blue 
Yellow 
Pink 
Blue 
Blue 
Pink 
Red 



; Unreliable 
I Reliable 

Unreliable 
1 Unreliable 
I Reliable 
! Unreliable 

Unreliable 



Reliable 
Unreliable 
Reliable 
Reliable 
Reliable 
Reliable 
Reliable 



Reliable 
Reliable 

Unreliable 
Reliable 
Reliable 

Unreliable 
Reliable 



Reliable 
Unreliable 

Reliable 

Unreliable ( ?) 

Unreliable 

Unreliable| 

Reliable 



* Talbot, Quantitative Analysis, page 75. 
■f Reliable with oxalic acid. 



REFERENCES ON LABORATORY EQUIPMENT, REAGENTS, ETC. 

Adriance, J. S. Laboratory Calculations. New York, 1897. 

Atkinson, E. Suggestions for the Establishment of Food Laboratories. U. S. Dept. 
of Agric, Off. of Exp. Sta., Bui. 17. 

CoHN, A. J. Tests and Reagents, Chemical and Microscopical, known by their Authors* 
Names. New York, 1903. 

KenwooD; H. R. Public Health Laboratory Work. The Hygienic Laboratory. Phila- 
delphia, 1893. 

KIrauch, C. Testing of Chemical Reagents for Purity. London, 1903. 

Lunge, G., and Hurter, F. Alkali-maker's Handbook. London, 1891. 

M.AYRHOFER, J. Instrumente und Apparate zur Nahrungsmittel Untersuchung. 
Leipzig, 1894. 

Mercks 1907 Index. Merck & Co., New York. 

Schneider, A. Reagents and Reactions known by the Names of their Authors. 1897. 

Sutton, F. Volumetric Analysis. 8th Ed. Philadelphia, 1900. 

Thorpe, T. E. Dictionary of Applied Chemistry. London, 1894. 



CHAPTER III. 

FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, AND 
NUTRITIVE VALUE. 

Nature and General Composition. — Food is that which, when eaten, 
serves by digestion and absorption to support the functions and powers 
of the body, by building up the material necessary for its growth and 
by supplying its wastes. The raw materials that constitute our food- 
supply are not all available for nourishment, but often contain a propor- 
tion of inedible or refuse matter, which it is customary to remove before 
eating, such as the bones of fish and meat, the shells of clams and oysters, 
eggshells, the bran of cereals, and the skins, stones, and seeds of fruits 
and vegetables. The proximate components which make up the edible 
portion of food include in general water, fat, various nitrogenous bodies 
consisting chiefly of proteins, carbohydrates, organic acids, and mineral 
matter. Of these water is hardly to be considered as a nutrient, though 
it plays an important part in nearly all foods as a diluent and solvent. 
The fats, proteins, and carbohydrates all contribute in varying degree to 
the supply of fuel for the production of heat and energy. Besides this 
universal function, the fats and the carbohydrates serve especially to fur- 
nish fatty tissue in the body, while the proteins are the chief source of 
muscular tissue. 

Liebig's classification of foods into nitrogenous, or flesh formers, and 
non-nitrogeneoiis, or heat generators, is now no longer accepted as strictly 
logical, in view of the welhknown fact that the nitrogenous materials, 
besides building up the body, aid in supplying the wastes and yielding 
energy, and may even be converted into fats or carbohydrates, while the 
non-nitrogenous aid in furnishing tissue growth in addition to serving as 
fuel. 

The Fat of Food. — Fats are the glycerides of the fatty acids, the 
characteristics of the various edible fats and oils being treated of under 

39 



40 FOOD INSPECTION AND /iN /I LYSIS. 

their appropriate headings elsewhere. Fat in human food is supphed by 
milk and its products, by the adipose tissue of meat, and in slight extent 
by the oil of cereals and by the edible table oils. The term "ether extract" 
is sometimes used in stating the results of the analysis of foods and this 
includes other substances than fat which when present are extracted by 
ether, such as chlorophyl and other coloring matters, lecithin, alkaloids, etc. 

Nitrogenous compounds and their Classification.— These sub- 
stances may for convenience be grouped as follows: 

A Proteins, B Amino-acids and Amides, C Alkaloids, D Nitrates, 
E Ammonia, and F Lecithin, 

A. PROTEINS. — This term includes a large number of nitrogenous bodies 
consisting, according to our present knowledge, essentially of combinations 
of a-amino-acids and their derivatives. Proteins in one form or another 
exist in nearly all natural foods both animal and vegetable. The terms 
"proteids" or "albuminoids "were formerlyused gcnericallyas synonymous 
with "protein" to include all nitrogenous bodies of this group, but recently 
a joint committee on protein nomenclature of the American Physiological 
Society and the American Society of Biological Chemists recommended 
that the word "proteid" be abandoned; that "protein" be used to designate 
the entire group; and that the word "albuminoids" be restricted to a sub- 
group of proteins. A committee of the Physiological Society of England 
also made the same recommendation as to the use of the term protein. 
The classification and most of the definitions here given are those adopted 
by the American committee.* 

Proteins available for food are supplied chiefly by the flesh of meat and 
fish, by milk, cheese, and eggs, and in the vegetable kingdom by seeds, 
nuts, and vegetables, especially the legumes. The proportion of crude 
protein, often designated merely as "protein," is commonly estimated by 
multiplying by 6.25 the percentage of nitrogen found in the material 
analyzed. This is done on the assumption that all of the nitrogen present 
in the substance belongs to protein containing 16 per cent of nitrogen. 

There is no marked distinction in chemical constitution between animal 
and vegetable proteins, although some of the types have as yet been found 
only in one or the other kingdom. All proteins are insoluble in pure 
alcohol or in ether. A few are soluble in water but most are not. Nearly 
all are soluble in very dilute acids or alkalies, while all are decomposed by 
boiling with concentrated mineral acids or concentrated caustic alkalies. 
All proteins are la-vo-rotary with polarized light. 

* Am. Jour. Phys., 21, 1908, p. xxvii. 



FOOD, ITS FUNCTIONS, FROXIMATE COVIPONENTS, ETC. 41 

Qualitative Test for Proteins. — Xanthoproteic Reaction.— Concen- 
trated nitric acid added to a solution of a protein may or may not form a 
precipitate. It, however, produces a yellow coloration on boiling. Addi- 
tion of ammonia in excess turns the precipitate or liquid yellow or orange. 
M moil's Reaction. — Millon's reagent No. 184, page 30, when added to 
a protein solution produces a white precipitate, which becomes brick-red 
on heating. Sodium chloride prevents the reaction. Various organic 
substances are precipitated by Millon's reagent, but these precipitates do 
not turn red on heating. 

Biuret Reaction. — If a solution of a protein in dilute sulphuric acid be 
made alkaline with potassium or sodium hydroxide and very dilute copper 
sulphate be added, a reddish to violet coloration is produced, similar to 
that formed if biuret* be treated in the same way, hence the name. An 
excess of copper sulphate should be avoided lest its color obscure that of 
the reaction. 

In solutions which are strongly colored this reaction is of little use 
unless modified as follows: A considerable quantity of the dilute copper 
sulphate solution is added to the solution made alkaline with a large excess 
of potassium hydroxide, and then solid potassium hydroxide is dissolved 
to almost complete saturation in the solution. The mixture is then shaken 
with about one half its volume of strong alcohol. On standing the alcohol 
separates as a clear layer of a violet or crimson color if proteins are present. 

I. THE SIMPLE PROTEINS. — Protein substances which yield only a- 
amino acids or their derivatives on hydrolysis. 

Although no means are at present available whereby the chemical 
individuahty of any protein can be established, a number of simple pro- 
teins have been isolated from animal and vegetable tissues which have been 
so well characterized by constancy of ultimate composition and uniformity 
of physical properties that they may be treated as chemical individuals 
until further knowledge makes it possible to characterize them more defi- 
nitely. 

(a) Albumins. — Simple proteins soluble in pure water and coagulable 
by heat. 

Examples. — Seralbumin of blood and other animal fluids; lactalbumin 
of milk; leucosin of the seeds of wheat, rye, and barley; legumelin of legu- 
minous seeds. 

* Biuret is the substance formed by heating urea to 160° according to the following 
reaction: 

2CON2H, = C2O2N3H5 + NH3. 
Urea Biuret Ammonia 



42 FOOD INSPECTION AND ANALYSIS. 

Coagulation. — Animal albumins usually coagulate at about 75°; 
vegetable albumins at about 65°. 

Miscellaneous Reactions. — Very dilute acids precipitate albumins with 

the aid of heat. Nitrate of mercury (in dilute nitric acid) precipitates 

albumins from their solutions; also Mayer's solution acidified with acetic 

acid. They are precipitated by saturation with ammonium sulphate. 

These reactions are not, however, characteristic of the group. 

(b) Globulins. — Simple proteins insoluble in pure water, but soluble in 
neutral solutions of salts of strong bases with strong acids. 

Examples. — Myosin of muscle substance; legumin of leguminous seeds; 
amandin of almonds. 

Qualitative Tests. — Globulins are precipitated from their solution by 
dialysis or dilution. Albumins are not thus precipitated. 

(c) Glutelins. — Simple proteins insoluble in all neutral solvents, but 
readily soluble in very dilute acids and alkalies. 

Examples. — Glutenin of wheat is the only well defined protein of this 
group. 

(d) Prolamins. — Simple proteins soluble in relatively strong alcohol 
(70-80 per cent), but insoluble in water, absolute alcohol, and other 
neutral solvents. 

Examples. — Gliadin of wheat ; zein of maize ; hordein of barley. Found 
as yet only in the seeds of cereals. 

The use of appropriate prefixes will suffice to indicate the origin of 
compounds of sub-classes a, b, c, and d, as for example: ovoglobulin, 
my albumin, etc. 

(e) Albuminoids. — Simple proteins which possess essentially the same 
chemical structure as the other proteins, but are characterized by great 
insolubility in all neutral solvents. 

Examples. — Keratins of hair, nails, hoofs, horn, feathers, etc.; elastin 
of connective tissues; collagen of connective tissues and cartilage ; fibroin 
and sericin of raw silk. No albuminoids have yet been discovered in plants. 

Gelatin is usually regarded as an albuminoid but does not come strictly 
within the requirements of the above definition. It is an artificial deriva- 
tive of collagen and is formed from it by boiling with water or subjecting 
to steam under pressure. It is prepared from bones and other animal 
parts, and is insoluble in cold, but soluble in hot water. When the hot 
water solution containing one per cent or more of gelatin cools, it forms a 
jelly. By prolonged boiling the gelatinizing power is lost. Aqueous 
solutions are strongly laevo-rotary. 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 43 

Gelatin in common with most proteins is precipitated from its solution 
by mercuric chloride, picric acid, and tannic acid. It is readily distin- 
guished from soluble proteins, in that it is not precipitated from its solution 
by lead acetate, nor by most of the metallic salts that throw down proteins. 

(f ) Histones. — Soluble in water and insoluble in very dilute ammonia, 
and, in the absence of ammonium salts, insoluble even in an excess of 
ammonia; yield precipitates with solutions of other porteins, and acoagu- 
lum on heating, which is easily soluble in very dilute acids. On hydrolysis 
they yield a large number of amino-acids, among which the basic ones 
predominate. 

Examples. — Thymus histone. Not found in plants. 

(g) Protamins. — Simpler polypeptides than the proteins included in 
the preceding groups. They are soluble in water, uncoagulable by heat, 
have the property of precipitating aqueous solutions of other proteins, 
possess strong basic properties, and form stable salts with strong mineral 
acids. They yield comparatively few amino-acids, among which the basic 
amino-acids greatly predominate. 

Examples. — Salmin, clupein, and other protamins of fish spermatozoa. 
Not found in plants. 

11. Conjugated proteins. — Substances which contain the protein 
molecule united to some other molecule or molecules otherwise than as a 
salt. 

(a) Nucleoproteins. — Compounds of one or more protein molecules 
with nucleic acid. 

Examples. — The nucleins formed by pepsin digestion. 

(b) Glycoproteins. — Compounds of the protein molecule with a sub- 
stance or substances containing a carbohydrate group other than a nucleic 
acid. 

Examples. — Mucins; ovomucoid; ovalbumin. 

(c) Phosphoproteins. — Compounds of the protein moiCCule with some 
yet undefined phosphorus-containing substance other than a nucleic acid 
or lecithins. 

Examples.— Cd^sem of milk; vitellin of egg yolk. 

(d) Haemoglobins. — Compounds of the protein molecule with haematin 
or some similar substance. 

Example. — Oxyhaemoglobin of red blood corpuscles. 

(e) Lecithoproteins. — Compounds of the protein molecule with lecithins, 
(lecithans, phosphatides). 

Examples. — Lecithalbumin ; lecithin-nucleovitellin. 



44 FOOD INSPECTION AND ANALYSIS. 

III. Derived Proteins. 

1. Primary Protein Derivatives, — Derivatives of the protein mole- 
cule, apparently formed through hydrolytic changes which involve only 
slight altterations of the molecule. 

(a) Proteans. — Insoluble products which apparently result from the 
incipient action of water, very dilute acids or enzymes. 

Examples. — Edestan; blood fibrin; insoluble myosin. 

(b) Metaproteins. — Products of the further action of acids or alkalies, 
whereby the molecule is so far altered as to form products soluble in very 
weak acids and alkalies, but insoluble in neutral fluids. 

Examples. — Acid albumin; alkali albumin. 

This group will thus include the familiar "acid proteins" and "alkali 
proteins," not the salts of proteins with acids. 

(c) Coagulated Proteins. — Insoluble products which result from (i) 
the action of heat on their solutions, or (2) the action of alcohol on the 
protein. 

Examples. — Albumin coagulated by heat or alcohol. 

2, Secondary Protein Derivatives. Products of the further hydro- 
lytic cleavage of the protein molecule. 

(a) Proteoses. — Soluble in water, uncoagulated by heat, and precipi- 
tated by saturating their solutions with ammonium or zinc sulphate. 

As thus defined this term does not strictly cover all the protein deriva- 
tives commonly called proteoses, e.g. heteroproteose and dysproteose. 

Subdivision of the Proteoses. — According to the proteins from which 
they are derived the proteoses may be designated albumose, from albumin, 
globulose, from globulin, vitellose, from vitellin, caseose, from casein, etc. 

Proteoses are subdivided into proto- proteose , soluble in water (both cold 
and hot) or in dilute salt solutions, but precipitated by saturation with 
salt; hetero- proteose, insoluble in water, and deutero- proteose, soluble in 
water, but not precipitated by saturation with salt. 

Vegetable proteoses are sometimes called phyt-albumoses. 

Qualitative Tests. — Besides responding to the biuret reaction (p. 41) 
proteoses are precipitated by nitric acid, the precipitate being soluble on 
heating, but reappearing on cooling. 

' Proto-proteose is precipitated from its solution by mercuric chloride 
and copper sulphate; hetero-proteose is precipitated by mercuric chloride, 
but not by copper sulphate. 

(b) Peptones. — Soluble in water, uncoagulated by heat, and not pre- 
cipitated by saturating their solutions with ammonium sulphate. 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 



AS 



Qualitative Tests. — Besides giving the biuret reaction, peptones are 
precipitated from their solution by tannic acid, picric acid,phosphomolybdic 
acid, and by sodium phosphotungstate acidified by acetic, phosphoric, or 
sulphuric acid. 

Peptones are the only soluble proteins not precipitated by saturation 
with ammonium sulphate. The following table, showing the reaction of 
proteoses and peptones, is due to Halliburton:* 



Variety 

of 
Protein. 



Hot and 
Cold Water. 



Hot and 

Cold Saline 

Solutions, 

e.g., io% 

NaCl. 



Satura- 
tion with 
NaCl or 
MgS04. 



Satura- 
tion with 
(NH4)2Sa 



Nitric Acid. 



Copper 
Sulphate. 



Copper 

Sulphate 

and Caustic 

Potash. 



Proto- 
albumose 



Hetero- 
albumose 



Deutero- 
albumose 



Peptone 



Soluble 



Insoluble; i.e. 
precipitated 
by dialysis 
from saline 
solutions 



Soluble 



Soluble 



Soluble 



Soluble: part- 
ly precipita- 
ted, but not 
c o a g ulated 
o n heating 
to 6s° C. 

Soluble 



Soluble 



Precipi- 
tated 



Precipi- 
tated 



Not pre- 
cipitated 



Not pre- 
cipitated 



Precipi- 
tated 



Precipi- 
tated 



Precipi- 
tated 



Not pre- 
cipitated 



Precipitated 
in cold; pre- 
cipitate dis- 
solves with 
heat and re- 
appears on 
cooling 

Ditto 



This reaction 
occurs only 
in presence 
of excess of 

salt 

Not pre- 
cipitated 



Precipi- 
tated 



Precipi- 
tated 



Not pre- 
cipitated 



Not pre- 
cipitated 



Rose-red 
color (biu- 
ret reac- 
tion) 



Ditto 



Ditto 



Ditto 



ic) Peptides. — Definitely characterized combinations of two or more 
amino-acids, the carboxyl group of one being united with the amino group 
of the other, with the elimination of a molecule of water. 

The peptones are undoubtedly peptides or mixtures of peptides, the 
latter term being at present used to designate those of definite structure. 

B. AMINO-ACIDS, Amides, and Allied products. — Under this 
head are included products derived from acids or bases, the radicles of 
which replace one or more of the hydrogen atoms in ammonia. The most 
common bodies of this class occuring in food products are: 

(i) Cholin (C5HJ5NO2), found in the muscular tissue of cattle and in 
yolk of eggs, also in certain fungi. 

(2) Betaine (C5H^jN02), found in certain moUusks, as, for instance, 
the mussel, in putrefying fish, and (in the vegetable kingdom) in beets and 
hops. It is formed by the oxidation of cholin. 

(3) Asparagin (C^HgNgOs), found in the shoots of asparagus, lettuce, 
peas and beans, and in the root of the marshmallow. It may be crystal- 



* Chemical Physiology and Pathology, page 131. 



46 FOOD INSPECTION AND ANALYSIS. 

lized out from the expressed juice of the asparagus shoots by evaporatioi 
after having removed the albumin by coagulation (by boiling) and byl 
filtration.* 

Asparagin when heated with alkalies forms ammonia, and with acids 
forms ammonium salts. Freshly prepared copper hydroxide is dissolved 
by an aqueous solution of asparagin by the aid of heat. If sections of 
vegetable tissues containing asparagin are placed in alcohol, crystals 
of asparagin are formed in such a manner as to be detected under the 
microscope. t 

Closely allied to the amides are the flesh bases of meat, chief among 
which are creatin (C^HyNjOa), creatinin (C4H-N3O), derived from crea- 
tin by the action of mineral acids and existing in some fish, cam in 
(C^HsN.Oa), and xantkin (C5H,N,02). 

C. AlkaloidAL Nitrogen. — Alkaloids do not naturally occur in 
foods, with the exception of tea, coffee, and kola-nuts, which contain 
caffeine, and cocoa, which contains theobromine. 

D. Nitrogen as Nitrates. — Foods in their natural condition rarely 
contain nitrates. Aleats cured with saltpetre furnish the most common 
instance of nitrates in food. Nitrates are tested for by extracting the 
sample with water, and treating the extract with ferrous sulphate and 
sulphuric acid in the usual manner. 

E. Nitrogen as Ammonia. — Ammonia occurs very sparingly in 
food, unless the latter has undergone some form of decomposition. In 
ripened cheese and in sour milk one sometimes finds it in minute quan- 
tities. Its presence is tested for by distilling the finely divided sample in 
water free from ammonia, and testing the distillate with Nessler's reagent. 

F. Lecithin.— This substance (Q4H90NPO9) is a phosphorized 
fat, and forms a part of the cell material in certain animal and vegetable 
foods. It is found in considerable quantity in the yolk of egg, and, in 
traces, in cereals, peas, and beans. It is a yellowish-white solid, soluble 
in ether and alcohol. Treated with water it swells up, forming an opales- 
cent solution or emulsion, from which it is precipitated by salts of the 
alkali metals. 

The Carbohydrates and their Classification.— The carbohy- 
drates supplied by food are milk sugar and the various sugars, starches, 
and gums from plant juices, cereals, fruits, and vegetables. Carbohy- 
drates are generally understood as being compounds of carbon, hydrogen, 
and oxygen, the last two elements being present in the proportion in 



* Zeits. fiir analytische Chemie, 22, page 325. 

t Wiley, Principles of Agric'l Analysis, \'ol. III. p. 427. 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 47 

which they occur in water. They are divided into three main classes, as 
follows : 

A. The Glucose Group, or Monosaccharids (CgHizOg), including 
dextrose, levulosc, and galactose. 

B. The Cane Sugar Group, or Disaccharids (CijHjjOn), including, 
cane sugar, milk sugar, and maltose. 

C. The Cellulose Group (CgHioOj), including starch, cellulose, dex- 
trin, gums, etc. 

Closely allied to the carbohydrates, if not actually belonging to them, 
are inosite (CgHijOe), occurring in muscular tissue, and pectose, found 
in green fruits and vegetables. 

The Organic Acids. — These acids are minor though important 
constituents of foods. From their conversion into carbonates within 
the body, they are useful in furnishing the proper degree of alkalinity 
to the blood and to the various other fluids, besides being of particular 
value as appetizers. They exist in foods both in the free state and as 
salts. Acetic acid is supplied by vinegar; lactic acid by milk, fresh meat, 
and beer; citric, malic, and tartaric acids by the fruits. 

Mineral or Inorganic Materials. — These substances occur in 
food in the form of chlorides, phosphates, and sulphates of sodium, potas- 
sium, calcium, magnesium, and iron, and are furnished by common salt, as 
well as by nearly all animal and vegetable foods. The inorganic salts are 
necessary to supply material for the teeth and bones, besides having an 
important place in the blood and in the cellular structure of the entire body. 

FUEL Value of FoOD.^In order to express the capacity of foods for 
yielding heat or energy to the body, the term fuel value is commonly used. 
By the fuel value of a food material is meant the amount of heat expressed 
in calories equivalent to the energy which we assume the body could obtain 
from a given weight of that food material, if all of its nutritents were 
thoroughly digested, a calorie being the amount of heat required to raise a 
kilogram of water 1° C. This definition applies to what is known as the 
large calorie, which is one thousand times as large as the small calorie. 
Large calories are meant wherever the term occurs in this volume. The 
fuel value, or, as it is sometimes called, "heat of combustion," may be 
determined experimentally with a calorimeter, or may be calculated by 
means of factors based on the result of many experiments showing the 
mean values for protein, fats, and carbohydrates. 

The Bomb Calorimeter.* — This apparatus in its most approved form, 

* U. S. Dept. of Agric, OflF. of Exp. Sta., Bui. 21, pp. 120-126. 



48 



FOOD INSPECTION AND ANALYSIS. 



Fig. 13, consists of a water-tight, cylindrical, platinum lined, steel bomb, 
adapted to hold in a capsule the substance whose heat is to be determined, 
and containing also oxygen under pressure. This bomb is immersed in 
water contained in a metal cylinder, which is in turn placed inside of 
concentric cylinders containing alternately air and water. The heat for 
igniting the substance is supplied by the electric current passing through 
wires to the interior of the bomb and acting upon a cleverly devised 
mechanism therein. The heat developed by the ignition is measured by 




Fig. 13. — Bomb Calorimeter of Hempel and Atwater 

the rise in temperature of the water surrounding the bomb, as indicated 
by a very delicate thermometer graduated to hundredths of a degree, 
certain corrections being made, as, for instance, for the heat absorbed by 
the metal of the apparatus. A mechanical stirrer serves to equalize the 
temperature of the water surrounding the bomb. 

Calculation 0} Fuel Value. — By reason of its great expense the calo- 
rimeter is beyond the reach of many laboratories, and on this account the 
expression of fuel values by calculation is the most common method em- 
ployed. For this the factors of Rubner are generally used, in accordance 
with which the amount of energy in one gram of each of the three principal 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 49 

classes of nutrients are, for carbohydrates 4,1, for protein 4.1, and for fats 
9.3. Expressed in pounds, each pound of carbohydrate or protein has a 
fuel value of i860 calories, while each pound of fat has a fuel value of 
4220 calories. 



REFERENCES ON DIETETICS AND ECONOMY OF FOOD. 

Albu, a., u. Neuberg, C. Mineralstoffwechsel. Berlin, 1906. 

Armsby, H. p. The Principles of xA.nimal Nutrition. New York, 1903. 

Atwater, W. O. Dietaries in Public Institutions. Yearbook of U. S. Dept. of 

Agric, 1901, page 393. 

Food and Diet. Yearbook of U. S. Dept. of Agric, 1894, page 357. 

Principles of Nutrition and Nutritive Value of Food. Farmer's Bulletin, 142. 

Bellows, A. J. The Philosophy of Eating. Boston, 1867. 

Burnet, R. W. Foods and Dietaries. Phil., 1893. 

Bry.ant, a. p. Some Results of Dietary Studies in the United States. Yearbook of 

U. S. Dept. of Agric, 1898, page 439. 
Chittenden, R. H. The Nutrition of Man. New York, 1907. 

Physiological Economy in Nutrition. New York, 190^1. 

Halliburton, W. D. Text-book of Chemical Physiology and Pathology. London, 

1891. 
Hammarsten, O. a Text-book of Physiological Chemistry. New York, 1898. 
Hutchinson, Robt. Food and the Principles of Dietetics. New York, 1901. 
Jaffa, M. E. The Study of Human Foods and Practical Dietetics. Cal. Exp. Sta. 

Bui. no. 
Knight, J. Food and its Functions. London, 1895. 
LusK, G. The Science of Nutrition. Philadelphia and London, 1906. 
Neumeister, a. Lehrbuch der physiologische Chemie. 1897. 
Pa\% F. W. a Treatise on Food and Dietetics. London, 1874. 
Richards, E. H. The Cost of Living as Modified by Sanitary Science. New York, 

1900. 

The Cost of Food: A Study in Dietaries. New York, 1901. 

Rubner, M. Die Gesetze des Energieverbrauchs bei Ernahrung. Leipzig, 1902. 

Simpson, H. Choice of Food. Manchester, England, 1889. Lectures. 

Strohmer, F. Die Ernahrung des Menschen. 

Thompson, W. G. Practical Dietetics. New York, 1895. 

Townshend, S. H. The Relation of Food to Health. St. Louis, 1897. 

True, A. C, and Milner, R. D. Development of Nutrition Investigations of the 

Dept. of Agric. Yearbook of U. S. Dept. of Agric, 1899, page 403. 
Storrs Exp. Station Annual Reports, 1888 et seq. 
Dietetic and Hygienic Gazette. 
Hygienische Rundschau. 

Revue de la Soc. Scientifique d'Hygiene Alimentaire, 1904 et seq. 
Zeitschrift fur Physiologische Chemie, 1877 et seq. 



5° FOOD INSPECTION ^ND /iN A LYSIS. 



Also the following bulletins of the Office of Experiment Stations, U. S. Department 
of Agriculture. 

21. ISIethods and Results of Investigations on the Chemistry and Economy of 
Food. By W. O. Atwater. Pp. 222. 

28. (Revised edition.) The Chemical Composition of American Food Materials. 
By W. O. Atwater and A. P. Bryant. Pp. 87. 

29. Dietary Studies at the University of Tennessee in 1895. By C. E. Wait, 
with comments by W. O. Atwater and C. D. Woods. Pp. 45. 

31. Dietary Studies at the University of Missouri in 1895, and Data Relating 
to Bread and Meat Consumption in Missouri. By H. B. Gibson, S. Calvert, 
and D. W. May, with comments by W. O. Atwater and C. D. Woods. Pp. 24. 

32. Dietary Studies at Purdue University, Lafayette, Ind., in 1895. By W. E. 
Stone, with comments by W. O. Atwater and C. D. Woods. Pp. 28. 

35. Food and Nutrition Investigations in New Jersey in 1895 and 1896. By 
E. B. Voorhees. Pp. 40. 

37. Dietary Studies at the Maine State College in 1895. By W. H. Jordan. Pp. 

57- 

38. Dietary Studies with Reference to the Food of the Negro in Alabama in 1895 
and 1896. Conducted with the cooperation of the Tuskegee Normal and 
Industrial Institute and the Agricultural and Mechanical College of Alabama. 
Reported by W. O. Atwater and C. D. Woods. Pp. 69. 

40. Dietary Studies in New Mexico in 1895. By A. Goss. Pp. 23. 

44. Report of Preliminary Investigations on the Metabolism of Nitrogen and 
Carbon in the Human Organism with a Respiration Calorimeter of Special 
Construction. By W. O. Atwater, C. D. Woods, and F. G. Benedict. Pp. 64. 

45. A Digest of Metabolism Experiments in which the Balance of Income and 
Outgo was Determined. By W. O. Atwater and C. F. Langworthy. Pp. 434. 

46. Dietary Studies in New York City in 1895 and 1896. By W. O. Atwater and 
C. D. Woods. Pp. 117. 

52. Nutrition Investigations in Pittsburg, Pa., 1894-1896. By Isabel Bevier. 
Pp. 48. 

53. Nutrition Investigations at the University of Tennessee in 1896 and 1897. 
By C. E. Wait. Pp. 46. 

54. Nutrition Investigations in New Mexico in 1897. By A. Goss. Pp. 20. 

55. Dietary Studies in Chicago in 1895 and 1896. Conducted with the coopera- 
tion of Jane Addams and Caroline L. Hunt, of Hull House. Reported by 
W. O. Atwater and A. P. Bryant. Pp. 76. 

56. History and Present Status of Instruction in Cooking in the Public Schools 
of New York City. Reported by Mrs. Louise E. Hogan, with an introduction 
by A. C. True, Ph.D. Pp. 70. 

63. Description of a New Respiration Calorimeter and Experiments on the 
Conservation of Energy in the Human Body. By W. O. Atwater and E. B. 
Rosa. Pp. 94. 

68. A Description of Some Chinese Vegetable Food Materials and their Nutri- 
tive and Economic Value. By W. C. Blasdale. Pp. 48. 



Bu 
Bu 
Bu 
Bu 

Bu 
Bu 
Bu 
Bu 



Bu 
Bu 



Bu 

Bu 

Bu 

Bu 

Bu 
Bu 

Bu 

Bu 

Bu 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC 51 

Bui. 69. Experiments on the Metabolism of Matter and Energy in the Human Body. 

By W. O. Atwater and F. G. Benedict, with the cooperation of A. W. Smith 

and A. P. Bryant. Pp. 112. 
Bui. 71. Dietary Studies of Negroes in Eastern Virginia in 1897 and 1898. By H. B. 

Frissell and Isabel Bevier. Pp. 45. 
Bui. 75. Dietary Studies of University Boat Crews. By W. O. Atwater and A. P. 

Bryant. Pp. 72. 
Bui. 84. Nutrition Investigations at the California Agricultural Experiment Station, 

1896-1898. By M. E. Jaffa. Pp. 39. 
Bui. 85. A Report of Investigations on the Digestibility and Nutritive Value of Bread. 

By C. D. Woods and L. H. Merrill. Pp. 51. 
Bui. 89. Experiments on the Effect of Muscular Work upon the Digestibility of Food 

and the Metabolism of Nitrogen. Conducted at the University of Tennessee, 

1897-1899. By C. E. Wait. Pp. 77. 
Bui. 91. Nutrition Investigations at the University of Illinois, North Dakota Agricul- 
tural College, and Lake Erie College, Ohio, 1896-1900. By H. S. Grindley 

and J. L. Sammis, E. F. Ladd, and Isabel Bevier and Elizabeth C. Sprague. 

Pp. 42. 
Bui. 98. The Effect of Severe and Prolonged Muscular Work on Food Consumption, 

Digestion, and Metabolism, by W. O. Atwater and H. C. Sherman, and the 

Mechanical Work and Efficiency of Bicyclers, by R. C. Carpenter. Pp. 67. 
Bui. 107. Nutrition Investigations among Fruitarians and Chinese at the California 

Agricultural Experiment Station, 1899-1901. By M. E. Jaffa. Pp. 43. 
Bui. 109. Experiments on the MetaboUsm of Matter and Energy in the Human Body, 

1898-1900. By W. O. Atwater and F. G. Benedict, with the cooperation of 

A. P. Bryant, A. W. Smith, and J. F. Snell. Pp. 147. 
Bui. 116. Dietary Studies in New York City in 1896 and 1897. By W. O. Atwater and 

A. P. Bryant. Pp. 83. 
Bui. 117. Experiments on the Effect of Muscular Work upon the Digestibility of Food 

and the Metabolism of Nitrogen. Conducted at the University of Tennessee, 

1899-1900. By C. E. Wait. Pp. 43- 
Bui. 121. Experiments on the MetaboHsm of Nitrogen, Sulphur, and Phosphorus in 

the Human Organism. By H. C. Sherman. Pp. 47. 
Bui. 126. Studies on the Digestibility and Nutritive Value of Bread at the University 

of Minnesota in 1900-1902. By Harry Snyder. Pp. 52. 
Bui. 129. Dietary Studies in Boston and Springfield, Mass., Philadelphia, Pa., and 

Chicago, 111. By Lydia Southard, Ellen H. Richards, Susannah Usher, Bertha 

M. Terrill, and Amelia Shapleigh. Pp. 103. 
Bui. 132. Further Investigations Among Fruitarians at the California Agricultural 

Experiment Station. By M. E. Jaffa. Pp. 81. 
Bui. 136. Experiments on the Metabolism of Matter and Energy in the Human Body, 

1900-1902. By W. O. Atwater and F. G. Benedict. Pp. 357. 
Bui. 143. Studies on the Digestibility and Nutritive Value of Bread at the Maine 

Agricultural Experiment Station, 1899-1903. By C. D. Woods and L. H. 

Merrill. Pp. 77. 



52 FOOD INSPECTION AND ANALYSIS. 

Bui. 149. Studies of the Food of Maine I>umbermen. By C. D. Woods and E. R. 
Mansfield. Pp. 60. 

Bui. 150. Dietary Studies at the Government Hospital for the Insane, Washington, 
D. C. By H. A. Pratt and R. D. Milner. Pp. 170. 

Bui. 152. Dietary Studies with Harvard University Students. By E. Mallinckrodt, 
jr. Pp. 63. 

Bui. 156. Studies on the Digestibility and Nutritive Value of Bread and Macaroni 
at the University of Minnesota. 1903-1905. By Harry Snyder. Pp. 80. 

Bui. 159. A Digest of Japanese Investigations on the Nutrition of Man. By K. 
Oshima. Pp. 224. 

Bui. 162. Studies on the Influence of Cooking upon the Nutritive Value of Meats 
at the University of Illinois, 1903-1904 By H. S. Grindley and A. D. Emmett. 
Pp. 230. 

Bui. 175. Experiments on ihe Metabolism of Matter and Energy in the Human Body. 
1903-1904. By F. G. Benedict and R. D. Milner. Pp. 335. 

Bui. 185. Iron in Food and Its Functions in Nutrition. By H. C. Sherman. Pp. 80. 

Bui. 187. Studies of the Digestibility and Nutritive Value of Legumes at the Uni- 
versity of Tennessee, 1901-1905. By C. E. Wait. Pp. 55. 

Bui. 193. Studies of the Effect of Different Methods of Cooking upon the Thorough- 
ness and Ease of Digestion of Meat at the University of Illinois. By H. S. 
Grindley. Pp. 100. 

Bui. 208. The Influence of Muscular and Mental Work upon Metabolism and the 
Efficiencv of the Human Body as a Machine. By F. G. Benedict. 



CHAPTER IV. 
GENERAL ANALYTICAL METHODS. 

Extent of a Proximate Chemical Analysis. — For purposes of studying 
the proximate composition of food for its dietetic value, it is nearly always 
necessary to make determinations of moisture, ash, fat, total nitrogen, and 
carbohydrates (when present), as well as of the fuel value. In some cases 
it may be desirable to proceed further, to make an analysis of the ash, for 
instance, to separate, at least into classes, the various nitrogenous bodies, 
especially in flesh foods, and perhaps to subdivide the starch, sugar, gums, 
and cellulose or crude fiber that make up the carbohydrates in the case of 
cereals. 

A.n analysis is considered complete whenever the purpose for which 
the examination has been made has been accomplished, and on that pur- 
pose depends solely the extent to which the various compounds present 
shall be subdivided and determined. Such a subdivision may be extended 
almost indefinitely. For example, a milk analysis may consist simply in 
the determination of the total solids and (by difference) the water. Again, 
it may be desirable to divide the milk solids into fat and solids not fat, 
and in some cases to carry the subdivision still farther and separate the 
solids not fat into casein, albumin, milk sugar, and ash. 

Determinations of one or more of the proximate components natural 
to food are frequently of great service in proving their purity or freedom 
from adulteration. For the latter purpose, especially in such foods as milk, 
vinegar, oils, and fats, the determination of specific gravity is also an 
important factor. Special methods of a peculiar nature are often neces- 
sary in the examination of particular foods, and such methods will be 
treated subsequently under the appropriate headings. In the present 
chapter only such general methods as are applicable to a large variety of 
cases will be discussed. 

Expression of Results of a Proximate Analysis. — However complete the 
division of the various proximate compounds or classes of compounds 

53 



54 FOOD INSPECTION AND ANALYSIS. 

which the analyst sees fit to make, the results of his various determina- 
tions in a proximate analysis are expected to aggregate about 100%. 
If every determination be directly made, the result will rarely be exactly 
100, but the precision of the work is apt to be judged by its approach 
to 100. 

It is often the custom to determine certain compounds or classes of 
compounds by difference. Thus in cereals moisture, proteins, fat, crude 
fiber and ash may be determined by the regular analytical methods, 
and by subtracting their sum from 100 the difference may be expressed as 
*' nitrogen- free extract" or carbohydrates. It has long been customary 
in food analysis to calculate the protein by multiplying the total nitrogen 
by the factor 6.25, and on this basis analyses of thousands of animal and 
vegetable foods have been made. While the figure thus obtained is an 
arbitrary one, being at best but a rough approximation of the amount of 
protein present, yet for many reasons there is much to commend this 
practice of reporting results. In the first place, in most cases it actually 
does approach the truth. Again, the nitiogenous ingredients of many foods 
are so numerous and varied, that for the evcry-day study of dietaries and food 
values it would be well-nigh impossible with our present knowledge to 
subdivide these compounds with any degree of accuracy, and especially 
with uniformity between different chemists, to say nothing of the time 
involved. 

From the fact that so many valuable analyses have already been 
expressed on the basis of NX6.25 for protein, the advantage of comparison 
with the results thus recorded would seem to be in itself a good reason 
for continuing the practice, especially until a factor that gives better 
average results can be adopted. By recording the actual nitrogen found 
as well as the "protein," old results may at any time be recalculated 
under new conditions, if found desirable. 

In flesh foods, when carbohydrates arc known to be absent, the total 
protein may conveniently be determined by dift"erence. Rather more 
progress has been made in the separation of the nitrogenous compounds 
of meats than of the vegetables and cereals, though the methods are by 
no means accurate or uniform. 

Most of the recorded analyses of vegetable foods express the carbohy- 
drates as a whole without attempting to subdivide them, at least further 
than possibly to express the crude fiber or cellulose separately. A much 
more intelligible idea of the dietetic value of these foods would be gained 
by a further separation into starch and sugars. 



GENERAL ANALYTICAL METHODS. 



55 



Preparation of the Sample.— It is at the outset of the utmost isiportance 
in all cases that a strictly representative portion of the food to be examined 
should be submitted to analysis. All refuse matter, such as bones, shells, 
bran, skins, etc., are removed as completely as possible from the edible 
portion and discarded. 

If the composition of the entire mass cannot be made homogeneous 
throughout, it may be best to select from various portions in making up 
the sample for analysis, in order to represent as fair an average of the 
whole as possible. 

Finally the sample, if solid or semi-solid, should be divided as finely 
as possible, by chopping, shredding, pulping, grinding, or pulverizing 
according to its nature and consistency. 

For disintegrating such substances as vegetables and meats for analysis, 
the common household rotary chopping-machine is admirably adapted. 
For pulverizing cereals, tea, coffee, whole spices, and the like, the mortar 
and pestle may be used, or a rotary disk mill or spice-grinder. 

Specific Gravity or Density of Liquids. — Where formerly it was cus- 
tomary to compare the density of liquids with that of water at 4° C. (its 
maximum density) it is now more common to refer to water at 15.5° C. 
or 20° C, making the determination at that temperature. A common 
form of expressing the temperature of the determination and the tempera- 
ture of the standard volume of water with which that of the substance is 
to be compared, is the employment of a fraction, the numerator of which 
expresses the temperature of the determination and the denominator 

15.5° 15.5° 100° 4° 

that of the standard volume of water, as — „"' 5' 5' ~Z C.* 

4 15-5 15-5 4 

When extreme accuracy in the determination of density is required, the 
pycnometer or Sprengel tube should be employed. 

The Hydrometer. — This instrument furnishes the most convenient and 
ready means of determining the density of liquids where extreme nicety 
is not required. If well made and carefully adjusted, the hydrometer 
may be depended on to three decimal places, but before relying on its 
accuracy, it should be tested by comparison with a standard instrument, 
or with the pycnometer. 

The liquid whose density is to be determined is contained in a jar 
whose inner diameter should be at least f " larger than that of the spindle- 

* Unless otherwise stated, all specific gravities in this volume are assumed to be expressed 

is;.S° 
on the basis of ^^~^ 

15-5° 



56 FOOD INSPECTION JND ANALYSIS. 

bulb, and the temperature of the hquid should be exactly 15.5° when the 
reading is taken. 

For best results for use with liquids of varying densities, the laboratory 
should be furnished with a set of finely graduated hydrometers, each 
limited to a restricted part of the scale, together with a universal hydrom- 
eter coarsely graduated, covering the entire range, to show by preliminary 
test which of the special instruments should be used. 

A convenient set of seven such hydrometers are graduated as follows: 
0.700-0.850, 0.850-1.000, 1.000-1.200, 1. 200-1. 400, 1. 400-1. 600, 1.600- 
1.800, 1.800-2.000, while the universal hydrometer has a scale extending; 
from 0.700 to 2.000. Another less delicate set of three only has one for 
liquids lighter than water and two for heavier liquids. Some instruments 
have thermometers in the stem. Others require a separate thermometer. 

The Westphal Balance (Fig. 14). — This instrument consists of a 
scale-beam fulcrumed upon a bracket, wliich in turn is upheld by a sup- 
porting pillar. The scale-beam is graduated into ten equal divisions. 
From a hook on the outer end of the beam hangs a glass plummet pro- 
vided with a delicate thermometer, the beam being so adjusted that when 
the dry plummet hangs in the air, the beam is in exact equilibrium, i.e., 
perfectly horizontal as shown by the indicator on its inner end. If the 
large rider be placed on the same hook as the plummet and the latter 
immersed in distilled water of the standard temperature at which the 
determinations are to be made (say 15.5° C), the scale-beam should 
again be in equilibrium if the instrument is accurately adjusted. As 
commonly made, the weight of the plummet including the platinum wire 
to which it is attached amounts to 15 grams, and the displacement of 
its volume to 5 grams of distilled water at 15.5° C, the normal temperature 
on which the determinations are based. Thus the unit (or largest) rider 
should weigh 5 grams, while the others weigh 0.5, 0.05, and 0.005 gram 
respectively. 

If, instead of distilled water, the plummet be immersed in the liquid 
whose density is to be determined, the position of the riders on the scale- 
beam, when so placed as to bring the same into equilibrium, and when 
read in the order of their relative size (beginning at the largest), indicates 
directly the specific gravity to the fourth decimal place. 

If the liquid is lighter than water, the large rider is first placed in the 
notch where it comes closest to restoring the equilibrium of the beam, 
but with the plummet still underbalanced. The rider next in size is 
then apphed in a similar manner, and, unless equilibrium is exactly re- 



GENER/IL /iNALYTICAL METHODS. 



57 



stored, the third and the fourth riders successively. If it happens that 
two riders should occupy the same position on the beam, the smaller 
is suspended from the larger. 

If the hquid is heavier than water, the method employed is the same 
except that one of the largest or unit riders is in this case always hung^ 
from the hook which supports the plummet, while the others cross the 




Fig. 14. — The Westphal Balance. 

beam at the proper points. If carefully made and adjusted, the Westphal' 
balance is capable of considerable accuracy. 

A delicate analytical balance can be used in place of the less carefully 
adjusted Westphal instrument, by hanging the Westphal plummet from 
one of the scale-hooks of the same, and employing a fixed support for the 
glass jar that holds the liquid in which the plummet is to be immersed. 
The support is so arranged that the scale-pan below it can move freely 
without coming in contact with it. This arrangement is shown in Fig. 15. 

The Pycnometer, or Sped fie- gravity Bottle. — Fig. 16 shows the twa 



58 



FOOD INSPECTION AND ANALYSIS. 



forms of pycnometer commonly made. The plain form has a ground- 
glass stopper with a capillary passage through it, the other has a fine ther- 
mometer connected with the stopper and a capillary side tube provided 
with a ground hollow cap. Both are made in different sizes to hold 
respectively lo, 25, 50, and 100 grams of distilled water at the standard 




Fig. 15. — ^The Analytical Balance Arranged for Determining Specific Gravity with the 

Westphal Plummet. 

temperature. It is convenient to have a counterweight for each pycnom- 
eter as fitted with its stopper, thus avoiding much trouble in calculation. 
The calculation of results is simplified also if the pycnometers are accurately 
constructed to contain exactly the weight of distilled water which they 
purport to contain at the standard temperature, but it is rather difficult to 
procure such instruments, especially of the form furnished with the ther- 
mometer. Most instruments hold approximately the amount specified, 
the exact net weight of distilled water which they hold at standard tem- 
perature being found by careful test and kept on record. In determining 
the density of a liquid, the pycnometer is carefully filled with it at a tem- 
perature below the standard, the stopper carefully inserted, and the bottle 
wiped dry. Care should be taken that the liquid completely fills the bottle 
and is free from air-bubbles. The net weight of the liquid is then taken 



GENERAL ANALYTICAL METHODS. 59 

on the balance, when the temperature has reached the standard (say 15.5° 
C), being careful to wipe off the excess of liquid that exudes from the capil- 
lary due to expansion. The net weight of the liquid is divided by that of 
the same volume of distilled water, previously ascertained under the same 
conditions at the same temperature, the result being the density of the 
liquid. 

The pycnometer with thermometer attachment is obviously susceptible 
of a greater degree of accuracy than the other form, since the temperature 
of the liquid, even though 15.5° C. at the start, soon rises. 




Fig. 16. — Types of Pycnometer. 

The writer prefers to use the pycnometer provided with the ther- 
mometer, but without the hollow cap that covers the capillary side tube, 
unless liquids like strong acids are to be operated on, that might other- 
wise injure the balance. By keeping the liquid to be tested for some time 
in a refrigerator, it acquires a temperature of from 10 to 12° C. It is 
then transferred in the regular manner to the pycnometer and the ther- 
mometer-stopper inserted (but not the hollow cap) and the bottle wiped 
dry. There is ample time to adjust the balance-weights with extreme 
care while the temperature of the liquid is rising, leisurely wiping off 



Co 



FOOD INSPECTION AND ANALYSIS. 



at intervals with a soft towel the excess that exudes from the capillary 
tube, the final weight of the dry bottle and contents being made at the 
exact temperature of 15.5° C. 

In taking the tare or adjusting the counterweight of a specific-gravity 
bottle, the latter should be perfectly clean and dry. It had best be rinsed 
first with water, then with alcohol, and finally with ether, all traces of the 
latter being removed by a current of dry air, or otherwise, before weighing. 
In making successive determinations of density of a number of different 
liquids with the same pycnometer, it is sufficient to rinse the bottle once 
with a little of the hquid to be tested before making each determination, 
when the various hquids are miscible. When the liquids are immiscible, 
the bottle should be carefully cleaned in the manner described in the 
previous paragraph before making each test. 

The Sprengel Tiihe. — The Sprengel tube is a variety of pycnometer 
useful when only a small quantity of the liquid to be tested is available. 
It is susceptible of great accuracy. It consists of a 
U-shaped tube (Fig. 17), each branch of which termi- 
nates in a horizontal capillary tube bent outward. 
One of the capillaries, h, has a mark m thereon and 
has an inner diameter of about 0.5 mm. The 
diameter of the other capillar}^, a, should not exceed 
0.25 mm. The Hquid at room temperature is as- 
pirated into the tube so as to fill it completely, the 
end h being dipped in the liquid while suction is 
apphed at the end a. The tube is then placed in a 
beaker of water kept at the standard temperature, 
the beaker being of such size that the capillar}'- 
ends rest on the edge. The temperature of the 
liquid in the tube may be assumed to be constant 
Fig. 17.— Sprengel Tube when there is no further movement due to contrac- 
for Determining Spe- tion in the larger capillary end, /^. The. meniscus of 
cific Gravity. ^j^^ liquid, when cooled, should not be inside the 

mark m, and is brought exactly to the mark by applying a piece of bibulous 
paper to the other end, a. If a drop or two of Hquid has to be added, this 
may be done by applying to the end a a glass rod dipped in the liquid. 
When exactly adjusted, the whole is wiped dry and quickly weighed, 
hung from the arm of the analytical balance. To avoid evaporation by 
contact with the air, the ends of the capillaries are sometimes ground 
to receive hollow glass caps not shown in the figure. 




GENERAL ANALYTICAL METHODS. 6i 

Determination of Moisture. — The moisture is usually calculated 
from the weight of dry residue left after driving out all the water by evapo- 
ration from a weighed portion of the sample, using generally from i to lo 
grams in a tared dish. Some substances readily part with their water 
at ioo°; others, again, require a much higher temperature or an extremely 
long heating. In general the highest possible degree of heat should be 
employed that will not affect the other constituents. Certain saccharine 
products should theoretically be dried at a temperature not exceeding 
70° on account of the dehydration of some of the sugars at higher tempera- 
tures. On the contrary, where readily decomposable organic matter 
is known to be absent and the character of the substance^.will permit, 
it is sometimes possible to employ temperatures considerably above 100° 
for quick drying. 

It is not always safe to assume that water is the only substance evap- 
orated on drying. Thus spices and other products containing essential 
oils give off appreciable quantities of these oils when dried at 100°. 

As it is rarely possible to attain a temperature higher than 98° in the 
water-oven, a gas-heated air-oven of the general type of that described 
on page 23, with ready means for controlHng the temperature, is best 
for general moisture determinations in the food laboratory. 

Platinum dishes like those described on page 133 are admirable for 
nearly all moisture determinations, but thin dishes of porcelain, glass, or 
metal may be used. Thin liquids and air-dry, powdered substances may 
usually be weighed directly in the dish and dried, without the use of an 
absorbent. 

With very moist substances containing much cellulose as well as water, 
it is often advantageous to weigh into the dish and allow to simmer for 
a long time on the water-bath, before drying to constant weight in the 
air-oven at higher temperature. 

Viscous substances should generally be spread over finely divided 
asbestos fiber, or pieces of pumice stone, or quartz sand, which should be 
previously ignited and weighed with the dish, the object being to divide 
up the weighed portion as finely as possible for its better exposure to 
the heated air in the drying-oven. 

Determination of Ash. — For determining the percentage of the ash 
or mineral matter, it is often convenient to use the portion previously 
weighed out and dried in obtaining the moisture, the dry residue after 
the second weighing being in such cases burnt in the original dish over 
a low f^ame. Or, if desired, a fresh portion of the original substance may 



62 FOOD INSPECTION AND ANALYSIS. 

be air-dried or subjected to a preliminary dr}ung in the water-bath and 
then burnt, taking care that there is no loss by sputtering or otherwise. 

Platinum dishes will be found much the most convenient in all cases 
where they may be safely used. In general the shallow flat dishes de- 
scribed on page 133 are preferable. Where lead or tin compounds are 
present, or when sulphides, sulphates, or phosphates are to be burnt with 
reducing agents, platinum is sure to be attacked and porcelain dishes 
or crucibles should be used instead. Platinum is also attacked at ordinal y 
temperatures by free chlorine and bromine, and, when ignited, by free 
sulphur, phosphorus, arsenic, and iodine, by sulphides and by sodium or 
potassium hydroxide, nitrate and cyanide. Platinum dishes are liable to 
injury also when used for the ignition of sulphates, and phosphates with 
reducing substances, or with metals present that are reduced in fusion, 
such as mercury, bismuth, tin, lead, zinc, antimony, etc. 

The degree of heat employed in ashing should be the lowest possible to 
insure complete oxidation of the carbon, so as to avoid driving off certain 
volatile salts that are sometimes present and that would be lost if the heat 
were too high. At a bright red heat potassium and sodium chloride are 
slowly volatilized, and calcium carbonate is converted into oxide; further- 
more alkali phosphates fuse about particles of carbon, protecting 
them from oxidation. To avoid overheating it is recommended not to 
allow the flame to impinge directly against the dish, but to carry out the 
burning on a piece of asbestos paper supported on a triangle. The asbestos 
also serves to distribute the heat and to protect the dish from the injurious 
action of the direct flame on long heating. In order to burn off the last 
traces of carbon, a second piece of asbestos paper may be placed over the 
top of the dish, or the incineration may be comjjleted in a muffle furnace. 
Heating should be continued till the carbon is afl oxidized, which is in 
most cases indicated by a white ash. It is, however, sometimes impos- 
sible to obtain a perfectly white ash, but the appearance of the ash usually 
indicates when all the carbon has been burnt off. It is sometimes necessary 
to stir the contents of the dish with a stiff platinum wire from time to time 
during the ignition, the wire being weighed in with the dish. 

After ignition the dish is cooled in the desiccator before weighing. 

If an examination of the ash for special ingredients is reqviired, it 
is often necessary to burn a large portion of the sample. In this case 
it may be desirable to hasten the ignition by the careful use of ammonium 
nitrate as an oxidizing agent, or, in very refractory cases, as when sugar 
is present, it is well before igniting to saturate the sample with concen- 



GENERAL ANALYTICAL METHODS. 



63 



trated sulphuric acid, when the presence of sulphates in the ash is not 
objectionable. 

Methods for the detection and determination of the various ash ingre- 
dients are considered on pages 301 to 305. Such cases as are peculiar to 
certain foods, like the metallic impurities that occur in canned, bottled, 
and preserved foods under certain conditions, will be considered in their 
appropriate place. 

Extraction with Volatile Solvents. — Wher- 
ever it is necessary to exhaust a substance of its 
ether-soluble or alcohol-soluble ingredients, 
some form of continuous extraction apparatus 
is employed with advantage. 

The Soxhlet Extractor. — This apparatus, 
or one of its modifications is most commonly 
employed for continuous extraction. Fig. 18 
shows the simplest form of the Soxhlet ex- 
tractor, consisting essentially of a wide tube, 
A, provided with the side siphon a, a con- 
denser, B, and a wide-mouthed flask, C, all 
connected together in the manner illustrated, 
either by soft, accurately fitting corks or by 
ground joints, or by mercury-sealed connec- 
tions. Care in either case should be taken 
to have the joints perfectly tight, so as to 
avoid loss by leakage. The construction is 
such that the substance to be extracted, which 
is contained in the tube A, is subjected to 
successive treatment with freshly distilled 
portions of the solvent. The vapor from the 
solvent, boiling in the flask C, passes up 
through the side tube a' into the cold con- 
denser 5, where it is again reduced to liquid ^^^ iS^^rhTsoxhlet Extractor 

and falls drop by drop upon the substance to be with Electric Heater, 

extracted, which is confined in a suitable porous receptacle or perforated 
vessel in the tube A. The substance is thus allowed to macerate in the 
solvent till the level of the latter reaches the top of the siphon, when 
all of the solvent in the tube drains off into the flask C, carrying with it 
whatever it dissolves. The operation is at once repeated, the substance 




<54 FOOD INSPECTION AND ANALYSIS. 

being subjected to successive extractions with freshly distilled portions 
of the solvent, which leaves behind in the flask C whatever it dissolves. 
This operation of continuous extraction, when the conditions are right, 
goes on indefinitely without attention. 

The weighed portion of the sample to be extracted (from 2 to 5 grams) 
is first deprived of its moisture by drying, if free from volatile oil, and 
then transferred to the bottom of the tube A. There are various methods 
of doing this. If the substance is a fluid or semi-fluid like milk, it may 
be taken up on an absorption- coil of fat-free filter-paper and dried (see 
page 135), the dried coil being transferred to the tube A. Or the sample 
may be weighed into a ver}' thin glass shell (Hoffmeister's Schalchen) 
in which it is dried, after which the shell is wrapped in bibulous paper, 
■crushed between the fingers into small bits, and the whole, in the form 
of a small packet, is placed in the tube A. Or, again, the material, if 
in the form of an air-dried powder, may be weighed in a tared platinum 
dish or watch-glass and transferred by a brush into a partly folded wrapper 
of filter-paper, the ends of which are afterwards closed in by folding lo 
form a packet, which is first dried thoroughly in the oven and then placed 
in the tube A. The fat-free porous shells made by Schleicher & Schiill, 
in various sizes to fit the Soxhlet tubes, form convenient receptacles 
for the extraction of dry substances. The sample may in most cases 
be directly weighed into one of these shells after taking its tare, and the 
drying and extraction carried out at once. 

Preliminary to conducting the extraction, the flask C, Fig. 18, is thorough- 
ly cleaned and dried and then weighed, after which enough of the solvent 
reagent is poured into it to last through the period of the extraction, and 
the parts of the apparatus are connected. 

The heater employed should be a water-bath, or, as shown in Fig, 18, 
an electric stove, which may be provided with a fractional rheostat for 
varying the amount of heat. 

The degree of ebullition is so regulated as to allow the solvent to saturate 
the sample and siphon over into the flask C from six to twelve times an 
hour, the extraction being continued from two to six hours, or until all the 
ether-soluble material has been removed. Care should be taken also that 
the rate of boiling and the rate of condensation are so regulated that no 
appreciable loss of reagent occurs during the extraction. A strong smell of 
ether perceptible at the top of the condenser indicates a loss. The solvent 
is recovered at the end of the extraction by disconnecting the weighing 
flask at a time when nearly all of the solvent is in the part A and before 



GENERAL ANALYTICAL METHODS. 



65 



M 



-s'rS 




it is ready to siphon over. The weighing-flask is then freed from all 
traces of the solvent by drying first on the water-bath and then in the 
oven, after which it is cooled in the desiccator and weighed, the difference 
between this and the first weighing representing the weight of the fat or 
ether extract. 

The Johnson Ex', actor. — This form of apparatus (Figs. 19 and 20) has 
the advantage of the Soxhlet extractor in that it is simpler and employs a 
much smaller amount of ether. The substance is 
contained in the inner tube of the extractor (Fig. 
19), which is closed at the lower end by one thick- 
ness each of filter paper and cheese cloth, held tightly 
in place by means of a linen thread wrapped several 
times about the tube in the constriction and tied in 
a fast knot. This innner tube properly prepared 
can be used over and over for extractions. The 
outer tube, also shown in Fig. 19, is of such a size 
that the inner tube fits loosely within it. A shght 
bulge on one side prevents trapping by means of 
the condensed solvent. The extraction flask is 
preferably of only 30 to 35 cc. capacity. It is 
attached to the extractor, as is also the extractor to 
the condenser tube, by means of a carefully bored 
cork stopper. For ordinary determinations of ether 
extract the outer tube should have an inside diam- 
eter of 26 mm. and the inner tube an outside diam- 
eter of 22 mm, only 8 to 10 cc. of the solvent being 
required. If, however, large amounts of material fig. 19.— Johnson Extrac- 
(25 to 50 grams) are to be extracted, the diameters ^^°^ Tubes. 

may be made 32 mm. and 28 mm. respectively and a larger amount of sol- 
vent employed. 

Where only a few extractions are made, the heating can be performed 
over (but not on) a metal plate heated by a Bunsen burner, and the conden- 
sation effected by an ordinary Liebig condenser. If, however, a considerable 
number of extractions are carried out, the set apparatus shown in Fig. 20 
will be found convenient and also economical of space. It may be attached 
to the wall or placed at the back of a working desk. The heating, as shown 
in the cut, is effected by means of two steam pipes, but some form of elec- 
tric heater answers equally well. The case with glazed door prevents the 
radiation of heat. At the top is shown the multiple condenser consisting 



66 



FOOD INSPECTION /IND ANALYSIS. 



of a copper tank with block tin tubes. Water is introduced at the left 
and carried off at the right. 

The solvent is best poured through the material, thus obviating in large 
degree the crawling of the extract. The door should be opened several 
times during the extraction and kept open for a few minutes for the pur- 




FiG. 20. — Johnson Multiple Extraction Apparatus with Heating Closet and Condenser. 

pose of rinsing down the sides of the tubes by means of the condensed 
vapors. 

Preparation of Solvents.— in taking the so-called ether extract, some- 
times reckoned as fat, the solvent employed is either ethyl ether o^ the 
cheaper petroleum ether. Whichever reagent is employed, certain 
precautions are necessary for the purity of the reagent. If ethyl ether 
is used, it should be entirely freed from moisture and alcohol by first 
shaking with water to remove the larger portion of the alcohol, allowing 
it to stand for some time over dry calcium chloride, and then distilling 
over metallic sodium. The ether thus prepared should be kept till used 
with sodium in the container, the latter being somewhat loosely corked, 
to allow escape of the hydrogen formed. 

Petroleum ether is variously termed benzine, naphtha, or gasoline. It 
should be low-boihng, preferably between 35° and 50°, and it is always 
best to redistil it before using, in order to be sure it is free from residue. 
As to the choice of the two reagents for use in fat extraction, it may be 
said that ethyl ether is the solvent most used, but if a large number of 
determinations are to be made, the lower cost of petroleum ether is to 



GENERAL ANALYTICAL METHODS. 



67 





Fig. 21. — Fractionating-still, Arranged for Petroleum Ether, 



Fig. 22. — A Convenient 
Form of Separatory 
Funnel. 



68 



FOOD INSPECTION AND AN /I LYSIS. 



be considered. A convenient still for fractionating such substances as 
petroleum ether is shown in Fig. 21. 

Extraction with Immissible Solvents. — It is frequently necessary to 
dissolve out a substance from a liquid by shaking it with an immiscible 
solvent, as, for example, in the extraction of certain preservatives from 
aqueous or acid solutions with ether, petroleum ether, or chloroform. 
This can be done by shaking in ordinary flasks, but is attended by some 
difficulty and loss on decantation. A separatory funnel of the type shown 
in Fig. 22 is almost indispensible for this kind of extraction. The liquid 




Fig. 23. — Separatory Funnel Support. 



and solvent are transferred to the funnel, which is then stoppered and 
shaken. If the solvent is heavier than water, as in the case of chloroform, 
it is drawn off from beneath through the outlet-tube of the funnel, closing 
the tap when the line of demarkation between the two liquids reaches the 
tap. Or, if the solvent is the lighter, as in the case of ether, the aqueous 
liquid lying beneath is first drawn off and iinally the solvent is poured out 
through the top. If troublesome emulsions form when shaken, they may 
frequently be broken up by adding an excess of the solvent and again very 
gently shaking, or by careful manij)ulation with a stirring rod. If the 
solvent is ether, and an obstinate emulsion forms, it may frequently be 
broken by the addition of chloroform. Such a mixture of ether and chlor- 
oform sinks to the bottom and may be drawn off as in the case of chloroform 



GENE'-' A L ANALYTICAL METHODS. 69 

alone. Ether or chloroform emulsions that refuse to yield to either of the 
above methods may often be broken by the aid of a centrifuge. A conve- 
nient form of separatory funnel support is shown in Fig. 23. It serves for 
holding the separatory funnels v^hile dravi^ing from one into another, and 
is also useful as a support for ordinary funnels. The two shelves are adjus- 
table by means of thumb screws. The holes in these shelves are somewhat 
wider than the slots, so that the separatory funnels after being introduced 
through the latter drop into position and are held firmly while manipulating 
the stop-cock. 

Determination of Nitrogen by Moist Combustion. — In. thus determin- 
ing nitrogen, the organic matter is first decomposed by digestion with 
sulphuric acid and an oxidizer, the carbon and hydrogen being driven off 
as carbon dioxide and water respectively, while the nitrogen is converted 
into an ammonium salt, from which free ammonia (NH3) is later liberated 
by making alkaline. The ammonia is then distilled into an acid solution 
of known value and calculated by titrating the excess of acid. 

In the Kjeldahl process the oxidation is effected by means of a mercury 
compound, in the Gunning method, by potassium sulphate which forms 
the bisulphate with the acid. 

Neither method in its simplest form is applicable in the presence of 
nitrates; if these are present, a modification must be used. The Gunning- 
Arnold method (page 432) is employed for the determination of nitrogen 
in pepper, as the piperin is not completely decomposed by the usual 
processes. 

The Gunning Method. — Reagents: 

Standard alkali solution, N/io NaOH.* 
I Pulverized potassium sul[jhate. 

Sulphuric acid, concentrated. 
I Sodium hydroxide, saturated solution. 

Standard acid solution, N/io H2SO4 or HCL* 

An indicator, cochineal. 

Granulated zinc. 



* Winton employs standard acid of such a strength that i cc. is equivalent to i% of 

! nitrogen, working on a gram of material, and titrates back with standard alkali two and 
one-half times weaker than the acid. In order to insure accurate readings, burettes of 
narrow bore (i cc.= 2.6cm.) are employed. The alkali burette is so graduated that a 
reading of i corresponds to 2.5 cc, thus allowing for the greater dilution. The advantage 
' of this system is that the per cent of nitrogen is obtained by simply subtracting the alkali 
|| reading from the number of cc. of acid employed. 



70 FOOD INSPECTiON AND ANALYSIS. 

The digestion and distillation arc preferably carried out in the same 
flask, which should be pear-shaped with ilat or round bottom and made of 
moderately thick Jena glass. A convenient size has the following dimen- 
sions; length 29 cm., maximum diameter 10 cm., taj)ering gradually to a 
long neck, which near the end is 28 mm, in diameter with a flaring edge. 
Its capacity is about 550 cc. 

If desired, the digestion may be conducted in a smaller hard-glass 
flask of about 250 cc. capacity and of the same shape as the above, 
and the distillation in an ordinary round-bottomed flask of 500 cc. 
capacity. 

Introduce from 0.5 to 3.5 grams of the sample into the digestion-flask 
with 10 grams of potassium sulphate and from 15 to 25 cc. of concentrated ' 
sulphuric acid. The flask is inclined over the flame and heated gently 
for a few minutes "below the boiling-point of the acid till the frothing 
has ceased, after whicli the heat is gradually increased till the acid boils, | 
and the boiling is continued till the contents have become practically 
colorless or at least of a jxile straw color. \\'ire gau a> may lie interjiosed 
between the llask and tlame, but a triangle or a similiar supj-ori is to be 
preferred. 

The contents of the flask are then cooled, and, if the digestion has 
been conducted in the larger flask suitable also for distilling, as above 
recommended, 300 cc. of water are added and suflicient strong sodium 
hydroxide to make the contents strongly alkaline, using phenolphthalein as 
an indicator. If a separate flask is used for the distillation, the contents 
of the digestion-flask are transferred thereto with the water and the alkali 
added. A few pieces of granulated zinc should also be introduced, which 
by the evolution of gas pre^•ents bumping and the sucking back of the 
distillate. The flask is then well shaken and connected with the con- 
denser, the bottom of which is provided with an adapter, dipping below 
the surface of the standard hydrochloric or sulphuric acid, a measured 
quantity of which is contained in the receiving-flask. The distillation is 
then continued till all the ammonia has passed over into the acid, this 
part of the operation requiring from forty-five minutes to an hour and 
a half. As a rule the first 250 cc. of the distillate will contain all the 
ammonia. 

The excess of acid in the receiving-flask is then titrated with standard 
alkali, and the amount of nitrogen absorbed as ammonia is calculated. The 
reagents, unless known to be absolutely pure and free from nitrates and 



GENERAL ANALYTICAL METHODS. 



71 



ammonium salts, should be tested by conducting a blank experiment with 
sugar, by means of which any nitrates present are reduced. Any nitrogen 
due to imjiuritics should be corrected for. 

In purchasing sul[)huric acid for nitrogen determination it is important 
to specify that it be "nilrogen-frcc" as the so-called chemically pure acid 
often contains a considerable amount of nitrogen. 

Modijication of Gunning Melhod to include Nitrogen of Nitrates. — In 
addition to the reagents used in the simpler Gunning method, sodium 
thiosulphate and salicylic acid are required. 

A mixture of salicylic and sulphuric acids is made in the proportion of 
30 cc. of concentrated sulphuric to i gram of salicyHc. From 30 to 35 cc. of 




Fig. 34. — Bank of Stills for Nitrogen Determination by Gunning Process. 

the mixture are added to the 0.5 to 3.5 grams of the substance in the di- 
gestion-flask, the flask is well shaken and allowed to stand a few minutes, 



72 



FOOD INSPECTION AND ANALYSIS. 



occasionally shaking. Then 5 grams of sodium thiosulphate are added, 
and 10 grams of potassium sulphate, after which the heat is applied, at 
first very gently and afterwards increasing slowly till the frothing has 
ceased. The heating is then continued till the contents have been boiled 
practically colorless. From this point on, proceed as in the Gunning 
method. 

The Kkldahl Method. — One gram of the air dry substance, or a propor- 
tionately larger amount of a moist or liquid substance, and 0.7 gram of 
mercuric oxide (or an equivalent amount of metallic mercury) are placed 




Fig. 25. — Johnson Digestion Stand for Nitrogen Determination with Lead Pipe t.-r C-.rrymg 

off Fumes. 



in a 550 cc. Jena flask and 20 cc. of sulphuric acid added. The flask is 
placed in an inclined position over a Bunsen burner, and the mixture 
heated below boiling for 5 to 15 minutes or until the frothing ceases, after 
which the heat is raised until the mixture boils briskly. The boiling is 
continued until the liquid has become nearly colorless and for a half 
hour in addition. The lamp is then turned out, the flask placed in an 
upright position, and potassium permanganate slowly added with shaking 
until the solution takes on a permanent green or purple color. 

After cooling, 250 cc. of water are added, then 25 cc. of potassium 
sulphide solution (40 grams of the commercial salt in i liter of water), 



GENERAL ANALYTICAL METHODS. 



73 



sufficient saturated sodium hydroxide solution to render the solution 
alkaline, and finally a few grains of granulated zinc, shaking the flask 
after each addition. Without delay connect with the distillation appa- 
ratus, and proceed as in the Gunning method. 

Apparatus for Nitrogen Determination. — A bank of stills used by 
the author in nitrogen determination and in other processes is shown in 
Fig. 24. 

The digestion apparatus shown in Fig. 25 is that devised by Johnson, 
Winton, and Boltwood. The stand is of cast iron, with holes provided 




Fig. 26. — Johnson Distilling Apparatus for Nitrogen Determination. 



with three projections that support the flask. The lead pipe with 
holes for receiving the ends of the flasks serves to carry off the acid 
fumes. 

The Johnson distilling apparatus with accessories by Winton is shown 
in Fig. 26. The distillation tubes, except for the glass traps and bulb 
receiver tubes, are of block tin, and are cooled in a copper tank filled 
with water. The receivers for the distillate are ordinary pint milk 
bottles. 

At the left are two bottles with suspended tubes for measuring the 
potassium sulphide and sodium hydroxide solutions. 



74 FOOD INSPECTION AND ANALYSIS. 

Determination of Ammonia.^A weighed quantity of the finely 
divided sample, treated ^^'ith ammonia-free water and made alkaline with 
magnesium oxide free from carbonate, is distilled into a measured quan- 
tity of standard acid (tenth-normal hydrochloric or sulphuric acid) and 
the amount of ammonia determined by titration. 

Determination of Amido-nitrogen.* — In the absence of ammonia, or 
after the removal of the ammonia as described in the preceding section, 
the sample is boiled for an hour with 5% hydrochloric or sulphuric acid, 
which converts the amido-compounds into ammonium salts (chloride or 
sulphate). Assuming asparagin to be the amido-compound acted upon, 
the reaction is as follows: 

2C,H,N.03-|- H^SO,-^ 2H2O = (NH,),SO,-f 2C,H,NO,. 

Asparagin Ammonium Aspartic acid 

sulphate 

Exactly neutralize the free acid with sodium carbonate, add magnesia 
(free from carbonate), and distil into standard tenth- normal acid. The 
ammonia is determined by titration in the usual manner, and its nitrogen 
represents half of the nitrogen contained in the amido-compound, which 
it is customary to calculate as asparagin. 

Determination of the Various Carbohydrates. — Under title of " Cereals" 
in Chapter X are given in detail methods for separation and determination 
of sugar, dextrin, crude fiber, etc. 

Poisoned Foods. — Such metallic impurities as are present in food 
products incidental to their preparation, or as adulterants, will be con- 
sidered under title of the foods liable to such adulteration. 

The detection of highly toxic substances in food, such as arsenic, mer- 
curic chloride, the alkaloids, and other organic poisons that do not occur in 
food naturally or accidentally, and are present, not as adulterants properly 
so called, but have been added with criminal intent to do injury, come wnthin 
the province of the medico-legal chemist or toxicologist rather than that 
of the food analyst, and are beyond the scope of the present work. The 
methods involved are similar to those used in the detection of these poisons 
in the stomach, viscera, and other organs and tissues. The reader is 
referred in this connection to such treatises as those of Blyth f and Dragen- 
dorf. t The analyst is, however, so often called upon to test foods for 
arsenic that an exception in this case will be made. 

* Wiley, Agricultural Analysis, Vol. III. p. 424. 

t Poisons, their Effects and Detection. London, Griffen & Co., 1906. 

t Gerichtlich-chemische Ermittelung von Giften. St. Petersburg, 1876. 



GENERAL ANALYTICAL METHODS. 75 

Detection of Arsenic. — In testing most food substances for arsenic, it is 
usually unnecessary' to entirely destroy the organic matter, but whenever 
possible the substance under examination should, by treatment with con- 
centrated nitric and sulphuric acids, be brought into the form of a dry 
char, which may readily be divided finely by the action of a pestle in a 
mortar. In this condition the arsenic, which by the process has been 
oxidized to arsenic acid, may be completely dissolved by continual treat- 
ment with boiling water. The hot-w^ater solution containing the extract 
of the powdered char is then cooled, filtered, and submitted to the Marsh 
apparatus. 

For preliminary treatment of liquids or semi-liquid substances, proceed 
as directed under arsenic in beer, page 728, 

In treating substances like meats, vegetables, and the like, follow in 
general the directions of Chittenden and Donaldson * for organic tissues, 
the proportions of acid, etc., being varied to suit special conditions. Heat in 
a porcelain dish 100 grams of the finely divided substances with 23 cc. of 
pure concentrated nitric acid at a temperature between 150° and 160° C, 
stirring occasionally with a glass rod. After the substance has taken on 
a deep yellow or orange color, remove the dish from the heat, add 3 cc. 
of pure concentrated sulphuric acid, and stir while the nitrous fumes are 
given off. The operator should wear a rubber glove to protect the hands. 
Again heat to about 180° and add while hot, drop by drop, 8 cc. of pure 
concentrated nitric acid, stirring during the addition of the acid. Then 
heat at 200° till sulphuric acid fumes come off and a dry carbonaceous 
mass remains. 

This is then pulverized and exhausted with boiling water, and the 
aqueous solution, when cold, submitted to the Marsh test. 

The Marsh Apparatus and its Operation. — Fig. 27 shows a simple 
form of Marsh apparatus apphcable for this work. The generator is 
provided with a doubly perforated rubber stopper, containing the usual 
delivery-tube and the entrance-tube. The latter has for convenience 
a 60° funnel at the top, into which the filter- paper can ■ be folded and 
the solution containing the extract filtered directly into the generator. 
A chloride of calcium drying-tube is interposed between the generator 
and the capillary tube, the latter being drawn from hard arsenic-free 
tubing. 

The apparatus is operated in the usual manner, using arsenic-free 

♦American Chem. Journal, II. No. 4; Chem. News, Jan. 1881, p. 21. 



76 



FOOD INSPECTION AND ANALYSIS. 



granulated zinc and dilute sulphuric acid. After running the current 
of hydrogen long enough through the heated tube to prove the absence 
of arsenic in the reagents or apparatus, the aqueous solution of the char 
is poured into the moistened filter at the top of the funnel-tube and allowed 
to filter slowly into the generator. The length of time necessary to deposit 
in the capillary tube all the arsenic in the sample, or to prove the absence 
of arsenic, varies with the conditions, but in general if no darkening of 




Fig. 27. — Marsh Apparatus for Arsenic. 

the tube occurs after an hour, the sample may be considered free from 
arsenic. 

Estimation 0} Arsenic.^ — With the aid of an assay balance sensitive 
to o.ooooi gram, it is possible to weigh with accuracy an arsenic mirror 
in a cai)illary tube when the metallic arsenic amounts to o.oooi gram 
or more. Experience will soon show by the appearance of the mirror 
to the eye when that amount is exceeded. In this case the capillary tube 
containing the mirror is cut off from the bulk of the tube, and, after drying 
in a desiccator, is weighed on the assay balance. The capillary is then 
immersed in a solution of hypochlorite of sodium, which at once dissolves 
the arsenic only, if present, showing at the same time that the mirror is 
made up of arsenic and not antimony, which of course would not dissolve. 
The capillary is then washed, first by water by means of the wash- 
bottle, then with a few drops of alcohol, and is finally dried by heat. It 



* Leach, Annual Rep. Mass. State Board of Health, 1900, p. 700. Analyst's Reprint, p. 83. 



GENERAL ANALYTICAL METHODS. 77 

is then cooled and again weighed on the assay balance, the difference in 
weight corresponding to the metallic arsenic. 

If the amount of arsenic is small, it may be estimated by Sanger's 
method,* which consists in comparing the mirror in the capillary with 
a series of standard mirrors, made by using varying measured amounts 
of a standard arsenious oxide solution. This solution is prepared by 
dissolving i gram of pure arsenious oxide (AS2OJ in water with the aid of 
arsenic-free sodium carbonate, and, after acidification with dilute sulphuric 
acid, making up to a liter. Ten cc. of this solution are measured out 
carefully and made up to a liter with water, the strength of the dilute 
solution being 0.0 1 mgr. to i cc. One cc, 2 cc, 3 cc, etc, of this second 
or dilute solution are separately measured into the Marsh apparatus to 
give mirrors corresponding to the same number of hundredth-milligrams. 

Colorometric Analysis. — Certain analytical processes depend on the 
formation of a compound of the substance to be determined having a 
definite color, and the calculation of the quantity present from the inten- 
sity of the color of the solution, compared with that of a solution contain- 
ing a known amount. The comparisons may be made in a special form 
of cylinder or in a colorimeter. The latter has the advantage that a single 
solution of known strength serves within reasonable limits for matching 
any shade in the unknown solution, and for any number of determina- 
tions, the desired depth of the color being secured by varying the length 
of the column. 

Schreiner's Colorimeter.t — This apparatus, shown in Fig. 28, consists 
of two graduated tubes {B), containing the standard and unknown colori- 
metric solutions, the height of the column of liquid in both tubes being 
changed by two immersion tubes {A), which remain stationary while 
the graduated tubes arc raised or lowered in the clamy)s (C). The mirror 
D reflects the light through the tubes, and the mirror E reflects it again 
to the eye of the operator at F. 

In making the comparisons, the tube containing the solution of either 
known or unknown strength is set at a definite point, and the other tube 
is raised or lowered until the colors match. If R is the reading of the 
standard solution of the strength 5, and r the reading of the colorometric 
solution of unknown strength s, then 

s = —S. 
r 

* Proc. Acad, of Arts and Sciences, XXVI. (1891) p. 24. 
t Jour. Am. Chem. Soc. 27, 1905, p. 1192. 



78 



FOOD ANALYSIS AND INSPECTION. 



If desired, standard slides of colored glass, such as accompany the 
Lovibond tintometer, may be used at G for matching the solution of un- 
known strength, the value of these slides being 
determined by comparison with a standard 
solution. 

The Lovibond Tintometer may be used 
for colorometric chemical analysis, but is not 
so well suited for this purpose as the Schreiner 
colorimeter. It is especially designed for deter- 
mining the color value of liquid and solid 
technical products, such as beer, wine, oil, 
flour, paper, etc. 

The instrument itself is of simple construc- 
tion, consisting of an elongated box with an 
eyepiece at one end and two rectangular 
openings at the other, one for the solution or 
substance to be examined, the other for the 
standard glass slides used for matching the 
color. Light is reflected through the openings 
by means of a square piece of opal glass 
mounted on a jointed standard. Liquids are 
examined in rectangular cells with glass sides 
by transmitted hght, while powders are pressed 
into a form and examined by reflected light. 

The standard slides used in general work 
are red, yellow, and blue in even graduation 
from .006 to 20 tint units which can be combined so as to produce any 
desired tint or shade of any color. The results are expressed in terms 
of standard dominant colors (red, yellow, and blue), subordinate colors 
(orange, green, and violet) obtained by combining equal values of two 
dominant colors, and neutral tint (black) obtained by combining equal 
values of the three dominant colors. 




Fig. 28. — Schreiner's Colori- 
meter with a Tube showing 
Graduation. 



Thus 



o.6i? + 5.6F = o.60 + 5.oF 
o.o8i? + 1.57 + 0.25 = 0.08 A^ + o.i2G+ 1.3 F 
1.2R+ i.oB =^ i.oV -^o.2R 



in which 7? = red, F=yellow, 5 = blue, = orange, G = green, F=violet, 
iV = neutral tint or black. 



GENERAL ANALYTICAL METHODS. 79 

Special slides may be obtained for the examination of any desired 
product. For example, slides of brown shades are furnished for beer, 
of yellow shades for oils, and so on. 

REFERENCES TO GENERAL FOOD ANALYSIS. 

Alt.en, a. H. Commercial Organic Analysis. Philadelphia, 1898. 

AuTENRiETH, W. The Detection of Poisons and Strong Drugs. Trans, by W. H. 

Warren. Philadelphia, 1905. 
Balland, a. Les Aliments. Paris, 1907. 

Battershall, J. P. Food Adulteration and its Detection. New York, 1887. 
Bell, Jas. The Analysis and Adulteration of Foods, Pts. I and II. London, 1881. 
Blyth, a. W. and M. W. Foods, their Composition and Analysis. New York, 

1903. 

Poisons, their Eflfects and Detection. London, 1906. 

BOHMER, C. Die Kraftfuttermittel, ihre Rohstoffe, Herstellung, Zusammensetzung, 

etc. Berlin, 1903. 
Breteau, p. Guide Pratique des Falsifications et Alterations des Substances ali- 

mentaires. Paris, 1907. 
Bujard, a., and B.aier, E. Hilfsbuch flir Nahrungsmittel Chemiker. Berlin, 1894. 
BuRCKER, E. Traite des Falsifications et Alterations des Substances alimentaires et 

des Boissons. Paris, 1892. 
DiETZSCH, O. Die Wichtigsten Nahrungsmittel und Getranke. Zurich, 1884. 
Elsner, F. Praxis der Nahrungsmittel Chemiker. Leipzig, 1880. 
Ephraim, J. Originalarbeiten liber Analyse der Nahrungsmittel. Leipzig, 1894. 
Girard, C, et DupRE, A. Analyse des Matieres alimentaires et Recherche des leurs 

Falsifications. Paris, 1894. 
Hanausek, T. F. Die Nahrungs- und Genussmittel aus dem Pflanzenreiche. 1884. 
Hassall, a. H. Food, its Adulterations and the Methods for their Detection. London, 

1874. 
KONIG, J. Chemische Zusammensetzung der menschlichen Nahrungs- und Genuss- 
mittel. Berlin, 1903. 
Die Untersuchung landwirtschaftlich und gewerblich wichtiger Stoffe. Berlin, 

1906. 
Leach, A. E. Food: Methods of Inspection and Analysis. Article in Reference 

Handbook of the Medical Sciences, Vol. 3, pages 180-183. 
Leffmann, H., and Beam, W. Select Methods of Food Analysis. Philadelphia, 

1905. 
Mansfeld, M. Die Untersuchung der Nahrungs- und Genussmittel. Leipzig, 

1905. 
Nexjfeld, C. a. Der Nahrungsmittelchemiker als Sachverstandiger. Berlin, 1907. 
PoLiN et Labit. Examen des Aliments suspects. Paris, 1892. 
Richards, E. H., and Woodman, A. G. Air, Water, and Food. New York, 1900. 
Rottger, H. Kurzes Lehrbuch der Nahrungsmittel Chemie. Leipzig, 1903. 
Rupp, G. Die Untersuchung von Nahrungsmitteln, Genussmitteln und Gebrauchs- 

gegenstanden. 1900. 



8o FOOD INSPECTION AND AN /I LYSIS. 

Thoms, H., und Gilg, E. Einfiihrung in die praktische Nahrungsmittel-Chemie. 
Leipzig, 1899. 

VlLLEERS, A., et Collin, E. Traite des Alterations et Falsifications des Substances 
alimentaires. Paris, 1900. 

WiESNER, J. Die RohstofTe des Pflanzenreiches. Leipzig, 1900. 

Wiley, H. W. Principles and Practice of Agricultural Analysis. Vol. III. Agricul- 
tural Products. Chem. Pub. Co., Easton, Pa., 1906. 

The Analyst. London, 1877 et seq. 

Revue International des Falsifications. Amsterdam, 1888 et seq. 

Vierteljahresschrift der Chemie der Nahrungs- und Genussmittels. Berlin, 1884 et 

seq. (Discontinued 1897.) 
Zeitschrift fiir Untersuchung der Nahrungs- und Genussmittel. 1898 et seq. 
Vereinbarungcn zur Untersuchung und Beurtheilung von Nahrungs- und Genussmit- 

teln. Berlin, 1897. 
Also the following bulletins of the Bureau of Chemistry, U. S. Deptartment of 
Agriculture: 

Bulletin 13, Parts i-io. Food and Food Adulterants. 1887-1902. 
Bulletin 46. Methods of Analysis adopted by the A. O. A. C. 1899. 
Bulletin 65, Provisional Methods for the Analysis of Foods, adopted by the A. O. A. C. 

Nov. 14-16, 1901. 1902. 
Bulletin 107, rev. Ofiicial and Provisional Methods of Analysis. A. O. A. C. 1908. 



CHAPTER V. 
THE MICROSCOPE IN FOOD ANALYSIS. 

Microscopical vs. Chemical Analysis. — A very important means of 
idenlificalion of adulterants in many classes of food products is furnished 
by the microscope, which in many cases affords more actual information 
as to the purity of food than can be obtained by a chemical analysis. 
This is especially true of coffee, cocoa, and the spices, wherein the micro- 
scope serves to reveal not only the nature of the adulterants, but also not 
infrequently the approximate amount of foreign matter present. In the 
case of the cereal and leguminous products so commonly employed as 
adulterants, a microscopical examination is of paramount importance. 

The chemical constants of many of the adulterants of coffee and the 
spices do not always differ sufficiently from those of the pure foods in 
which they appear to be distinguished therefrom with accuracy and 
confidence by a chemical analysis alone. On the other hand, one who 
is familiar with the appearance under the microscope of the pure foods 
and of the starches and various ground substances used as adulterants, 
can, with certainty, identify very minute quantities of these materials, 
when present, with the same ease that one can recognize megascopically 
the most familiar objects about him. 

A chemical test may, for example, indicate the presence of starch, 
but it cannot reveal the particular kind of starch. The microscope will 
at once show whether the starch present is wheat or corn or potato or 
arrowroot, since these starches differ almost as much in microscopical 
appearance as do the physical characteristics of the grains or tubers from 
which they are obtained. Again, by a chemical analysis an abnormal 
amount of crude fiber may show the presence of a woody adulterant, 
but only the microscope will enable one to decide whether the impurity 
consists of sawdust or ground cocoanut shells. Not only in such in- 
stances as these is the microscopical examination of greater importance 



82 FOOD INSPECTION AND ANALYSIS. 

than a chemical analysis in estabhshing the purity of the food, but it 
is at the same time a much quicker guide. 

The Technique of Food Microscopy. — The recognition of adulterants 
by the microscope requires some experience but no more than may be 
acquired by a chemist who will give the subject serious attention. In 
the examination of cocoa, coffee, tea, and the spices for adulteration, a care- 
ful study of the powdered substance in temporary water mounting will 
in most cases prove sufficient to familiarize the food analyst with their 
characteristics under the microscope, and it is not absolutely necessary 
for him to familiarize himself with the details of section cutting, dissect- 
ing, or permanent mounting unless he so desires. The treatment in 
detail of these latter branches of vegetable histology is beyond the scope 
of the present work. For full information along these lines the reader 
is referred especially to such works as those of Behrens*, Zimmerman,! 
and ChamberlainJ together with the list of references on page 98. 

Standards for Comparison. — For standards the analyst should provide 
himself with as complete a set as possible of the various materials to be 
examined, taking care that their absolute purity is estabhshed. Wherc- 
ever possible, he should grind the sample himself from carefully selected 
whole goods. These, together with samples of the starches and other 
adulterants, all of known purity, should be contained in small vials care- 
fully stoppered and plainly labeled, arranged alphabetically or in some 
equally convenient manner in the desk or table on which the microscope 
is commonly used. The adulterants included in this set of standards 
should be not only those which experience has shown most liable to be 
employed, but any which, by reason of their character, might in the 
analyst's opinion be used under certain conditions. 

APPARATUS. 

The Microscope-stand. — An expensive or complicated stand is un- 
necessary. The prime requisites for good work in a microscope-stand are 
firmness or rigidity, and accuracy in centering. An inexpensive stand 
possessing these features can be used for the best work, providing the optical 
parts are satisfactory. It is well, if economy must be practiced, to purchase 
a simple stand provided with the society screw, and let the larger portion 
of the allowance go for a high grade of lenses, since many of the attach- 
ments inherent in a high-priced stand, though often of convenience, may 
well be dispensed with. 

* Guide to the Microscope in Botany. t Botanical Microtechnique. 

X Methods in Plant Histology. 



THE MICROSCOPE IN FOOD ANALYSIS. 



83 



A stand of the so-called continental type (having the horseshoe base) 
is preferable. A square stage is rather more convenient than the circular 
form, and the jointed pillar possesses advantages over the rigid variety 
in ease of manipulation that are certainly worth considering. 

The smooth working of both the coarse and fine adjustments should 
not be lost sight of. If the microscope is to be used exclusively for food 
work, a substage condenser is unnecessary, hence the construction of the 




Fig. 29. — CoiUiiiL-ntal Txpf (if Microscope. 

substage may be very simple, unless bacteriological work is to be done 
as well. 

A nose-piece, while not indispensable, is a great convenience for the 
quick transfer of objectives. A double nose-piece carrying two objectives 
is ample for routine food work. 

The Optical Parts are by far the most important, and should be of 
superior quality, though not necessarily of the most expensive makers. 
The food analyst should have at least two objectives, one for high- and 
one for low-power work, and preferably two oculars. 

For the routine examination of powdered food substances the writer 
prefers a |-inch objective, used with a medium ocular, the combination 
giving a magnification of from 240 to 330 diameters, according to the 
ocular employed. For a low-power objective the -|-inch is a conven- 



1 



84 



FOOD INSPECTION AND ANALYSIS. 



lent size. It is useful as a finder preliminary to examination with the 
higher power, and, in connection with a low-power eyepiece, is well adapted 
for the examination of butter and lard, and for use with the polariscope. 

An eyepiece micrometer mounted in an one inch ocular is indispen- 
sable for measuring starch grains and other elements. It is calibrated 
by means of a stage micrometer. 

The Micro-polariscope.— This accessory is useful in the identification 
of starches and other ingredients, and for ascertaining whether or not 
fats have been crystallized. The polarizer is held below the stage, while 
the analyzer is applied above the objective, either in the tube or above 
the ocular. 





Fig. 30. — Polarizer and Analyzer for the Microscope. 

A common form of construction is one in which the substage is adapted 
to carry interchangeably the diaphragm tube and the polarizer. If the 
polariscope is much used, it becomes desirable to provide means for 
quickly changing the polarizer and diaphragm tube below the stage, and 
for moving the analyzer in and out of place above the objective. 
Winton* has devised a microscope-stand with this in view, especially 
adapted to the needs of the food analyst. 

If the polariscope is to be used often, it is convenient to have within 
easy access two stands, one with the polariscope mounted in place in 
Connection with low-power glasses ready for use, and the other stand 
)rovided with the ordinary high- and low-power objectives only. 

Microscope Accessories include of necessity a large number of slides 
Ind cover glasses. The latter should be No. 2 thickness, f inch, either 
round or square. 

One or more dissecting-needlcs in holders and a small hand magni- 
fying-glass should also be provided. 

* Journal App. Microscopy, 2, p. 550. 



THE MICROSCOTE IN FOOD ANALYSIS. 



85 



Other useful accessories are a mechanical stage, a pair of fine tweezers, 
knives, scissors, and, if sections are to be cut, a plano-concave razor. 

MICROTECHNIQUE. 

Preparation of Vegetable Food Products for Microscopical Examina- 
tion. — The ground spices and cocoas of commerce are usually of the 
requisite fineness for direct examination without further treatment. Coffee, 
chocolate, starches, and similar products should be ground in a mortar 
fine enough to pass through a sieve with from 60 to 80 meshes to the inch. 

A small portion of the powdered sample is taken up on the tip of a 
clean, dry knife-blade, and placed on the microscope-slide. By means 
of a medicine-dropper a drop of distilled water is applied, and the wetted 




Fig. 31. — Mechanical Stage for Microscope. 

powder is then rubbed out under the cover-glass between the thumb and 
finger to the proper fineness. 

The water-mounted slide thus prepared, while useful only for tem- 
porary purposes, has proved to be best adapted to the analyst's require- 
ments for routine microscopical examination of powdered food products 
for adulteration, partly because water is the best medium in most cases 
for showing up the structural characteristics of these substances and their 
adulterants, and partly because it serves best for the ''rubbing out" 
process between thumb and finger under the cover-glass, whereby the 
sample is brought to the requisite degree of fineness. 

Experience will soon show how far this rubbing out should be carried 
for the best effects. Gentle pressure should be applied, care being taken 
not to break the cover-glass, especially if the sample contain anything of 
a gritty nature. The rubbing should be continued till the coarser par- 



86 FOOD INSPECTION AND ANALYSIS. 

tides and overlying masses are separated and distributed uniformly, but 
if too long persisted in, the forms of the tissues, starch grains, and other 
characteristic portions will be partially destroyed and of too fragmentary 
a nature to be readily recognizable. 

Canada Balsam is the best mountant for the examination of starches 
under polarized light. In this medium, under ordinary illumination, the 
starches are not plainly visible, since the refractive index of the balsam 
is so near that of the starch grains themselves. With the crossed nicols, 
however, the starch grains stand out very clearly and distinctly in a dark 
background. 

Specimens to be mounted in Canada balsam must be free from 
moisture. Dehydration is often resorted to by soaking the specimens in 
alcohol. Canada balsam in solution is prepared by dissolving the 
balsam broken into small pieces or powdered in a mortar in an equal 
volume of xylol, filtering and evaporating to sirupy consistency at room 
temperature. 

Glycerin Jelly* — This is the best permanent mountant for powdered 
food substances and is prepared as follows: i part by weight of the finest 
French gelatin is soaked two hours in 6 parts of distilled water, after which 
7 parts by weight of C. P. glycerin are added, and to each loo parts of 
the mixture add i part of concentrated carbolic acid. Heat the mixture 
while stirring till flocculency disappears and filter through asbestos while 
warm, the asbestos being previously washed and put into the funnel 
while wet. The jelly is soHd at ordinary temperatures, and must be 
warmed to melt. A small bit of this jelly is removed from the mass by 
a knife-blade and placed on the cover-glass, which is held over a gas flame 
till the jelly is melted. The powdered specimen being then shaken into 
the molten drop, the cover-glass is gently placed upon it (being brought 
down obliquely to avoid formation of air-bubbles) and pressed down in 
place. 

Microscopical Diagnosis. — It is never safe to pass judgment on a 
spice or other food by the microscopical examination of a single portion. 
Several sHdes should be prepared with bits of the powder taken from 
different parts of the mass, before the character and extent of the adultera- 
tion can be safely determined. Care should be taken that the slide, the 
knife-blade, the water, and the medicine-dropper be perfectly clean and 
free from contamination with previous specimens. 

It should be borne in mind that at best a composite powdered sample 

* Botan. Centralbl., Bd. i, p. 25. 



THE MICROSCOPE IN FOOD AN /i LYSIS. 87 

is but a mechanical mixture of various tissues, and that no two portions 
will show exactly the same composition. 

Characteristic Features of Vegetable Foods under the Microscope. — 

The structural features of a powdered spice, examined microscopically, 
will be found to differ considerably in appearance from those of a thin, 
carefully mounted section of the same spice. Instead of the beautiful 
arrangement of cells and cell contents with the perfect order of various 
parts as seen in the mounted section, one finds in the powdered sample 
under the microscope what often appears to be a most confusing mass 
of fragments of various tissues. For this reason the most striking charac- 
teristics seem to vary with different observers, and it is a well-known 
fact that microscopists differ widely as to conceptions of size, shape, and 
ordinary appearance, even in the case of certain of the well-known starch 
grains. It is on this account that, irrespective of the description of others, 
the analyst should familiarize himself with the microscopical appearance 
of the foods with which he is dealing, as well as of their adulterants, form- 
ing his own standards as to what constitute the recognizable features, 
from specimens prepared by himself. 

In the large variety of ground berries, buds, tubers, barks, etc., from 
which the spices and condiments are prepared, as well as in the grains, 
legumes, shells, fruit stones, and other materials forming the most familiar 
adulterants, the kinds of plant tissues and cell contents which, under 
the microscope, serve as distinguishing marks or guides for identification 
are comparatively few in number. 

The most common of these varieties of cell tissue and of cell contents 
to be met with by the food microscopist in his work are briefly the follow- 
ing: 

Parenchyma. — This is most abundant and widely distributed, forming 
as it does the thin-walled, cellular tissue of nearly all vegetable food sub- 
stances. The walls of parenchyma cells are, as a rule, colorless and 
transparent. The forms of the cells are varied and are often sufficiently 
characteristic in themselves to identify the substance under examination. 

Sclerenchyma, or stone cells, are the thick-walled woody cells forming 
the hard part of nut shells, fruit stones, and seed coverings, occurring also 
in some fruits and barks. These cells are more often colored and of 
various shapes but almost always irregular, sometimes elongated, as in 
cocoanut shells and olive stones occasionally nearly rectangular, as in 
pepper shells, and sometimes polygonal or nearly circular. 

In appearance the sclerenchyma cell commonly has a more or less 



FOOD INSPECTION AND ANALYSIS. 



deep, central or axial rift, from which small fissures extend through the 
thick walls, somewhat suggestive of the iris. See Fig. 33. 

Variously shaped sclerenchyma cells are found in allspice, cassia, 

g 




I 



Fig. 32, — Typical Forms of Various Cell Tissues. Longitudinal section through a clove, 
showing: Pp, two forms of parenchyma; B, bast fibers; g, vascular and sieve 
tissue; KK', cells with calcium oxalate crystals. (After Vogl.) 

pepper, clove stems, nut shells, etc. Stone cells are optically active to 
polarized light, and between crossed nicols are very conspicuous by their 
bright appearance. 



«c— 




Fig. z3>- — Sclerenchyma, or Stone-ceU Tissue. A cross-section through the stone-cell 
layer of the fruit shell of black pepper. (After Vogl.) 

Fibro-vasciilar Bundles are composed of three parts: the bast fibers, 
or mechanical elements, the phloem, and the xylem. 



THE MICROSCOPE IN FOOD ANALYSIS. 



89 



Bast Fibers are elongated, pointed sclerenchyma cells, of which flax 
fibers are examples. 

Sieve Tubes, the characteristic elements of the phloem, are thin- 
walled tubes with perforated partitions known as sieve plates. 

Vessels or Ducts occur in the xylem. They are designated as 
spiral, annular, reticulated, or pitted, according to the nature of the 
walls. 

Corky Tissue, or Suberin, constitutes the thin-walled, spongy cells 
forming the protective, outer dead layers of the bark. This is found 
in cassia, and in the barks used as adulterants. Suberin is tested for by 
potassium hydroxide (p. 93). (r^ 

Starch wherever it occurs furnishes the most charac- 
teristic feature of the cell contents, and, as a rule, will at 
once indicate under the microscope, by the shape and 
grouping of its granules, the particular substance of which 
it forms a part. It is very abundantly distributed through- 
out the vegetable kingdom and occurs in a wide variety of 
forms. It is particularly conspicuous when viewed by 
polarized light. Between crossed nicols such starches 
as corn, potato, and arrowroot show out brightly from 
a dark background with dark crosses, the bars of which ^^^' 34-— Reticula- 

, , . r 1 1 TTT1 1 • ted Ducts of Chic- 

mtersect at the hylum of each granule. When a selemte ^j^ (After Vogl") 
plate is introduced above the polarizer, a beautiful play of colors is 
seen with various starches, a phenomenon which Blyth appUes as a 
means of identification and classification, but which more modern micro- 
scopists regard as of minor importance to distinguishing the various 
starches morphologically. Starch is found naturally in the cereals^ legumes, 
and many vegetables, in cassia, allspice, nutmeg, pepper, ginger, cocoa, 
and turmeric. The cereal and leguminous starches from their inertness 
and cheapness constitute the most common adulterants of the spices and 
of powdered foods in general. Starch grains are found in the cells of the 
parenchyma and in other cellular tissues. Iodine is the special reagent 

(p. 9t). 

Gums and Resins occur in characteristic forms among the cell contents 
of some of the spices. As an example, the portwine-colored lumps of gum 
in allspice furnish one of the most ready means of recognizing that spice 
microscopically. Resin is tested for microchemically with alkanna tincture 
(p. 92). 




90 FOOD INSPECTION AND ANALYSIS. 

Aleurotte, or Protein Grains, occur in some of the spices, but are noi 
especially characteristic. They somewhat resemble small starch grains. 
Most varieties of protein grains are soluble in water, but some are insoluble. 
The soluble varieties, which are not apparent in water-mounted specimens, 
must be examined in absolute alcohol, glycerin, or oil. In leguminous 
seeds aleurone occurs closely intermingled with starch in the same cells, 
while in the cereals it occupies the whole cell. 

Protein grains are tested for under the microscope by iodine in potas- 
sium iodide, which turns them brown or yellowish brown, and by Millon's 
reagent, which colors them brick red. 

Plant Crystals are not uncommon in the class of substances which 
the food analyst examines. Among the common forms are the piperin 
crystals found in pepper. Calcium oxalate occurs in many vegetable 
products as prismatic crystals, crystal aggregates, or needle-shaped 
crystals (raphides). 

Crystals of calcium carbonate are sometimes met with also, as, for 
example, in hops. Calcium oxalate crystals are insoluble in acetic acid, 
while being readily soluble in dilute hydrochloric. Calcium carbonate 
crystals are soluble with effervescence in both acids. The acid reagents 
are directly applied to the sample in water-mount under the cover-glass, 
and the reaction observed through the microscope. 

Fat Globules are of common occurrence in many foods and appear of 
various sizes, sometimes large and conspicuous, and again almost lost 
sight of because of their minuteness. They are sometimes colorless, as in 
mace, and sometimes deeply tinted, as in cayenne. Alkanna tincture is 
used as a reagent for fat (p. 92). 

Other Cell Contents of less importance, but which may be identified by 
the microscope with reagents, are tannic acid (tested for by chloriodide 
of zinc and ferric acetate (pp. 91 and 92), and various essential oils, for the 
detection of which alkanna tincture is employed. 

REAGENTS IN FOOD MICROSCOPY. 
Unless a more extended microscopical investigation of vegetable food 
substances is contemplated than is involved in the mere identification of 
adulterants, the analyst will have little need for reagents,* but will depend 
almost entirely on the form and appearance of the various tissues or tissue 
fragments, as well as on the abundance, shape, and distribution of such 
distinctive cell contents as the starches, fat globules, or cr)'stals. 

* One reagent that is really necessary on the microscope-table, and will very often b<i 
required is iodine in potassium iodide. 



THE MICROSCOPE IN FOOD ANALYSIS. 91 

Analytical reagents are applied to the water-mounted sample by means 
of a glass rod or pipette, with which a drop of the reagent is deposited 
on the sample upon the slide, having previously removed the cover, 
which is afterwards replaced. Or, without removing the cover-glass, a 
drop of the reagent is placed in contact with one side of it on the 
slide. Along the opposite side of the cover is then placed a pi^ce of filter- 
paper. The latter withdraws by capillary attraction a portion of the water 
from under the cover-glass, and this is replaced by the reagent, which 
thus intermingles with the particles of the substance. 

Following is a brief list of the commoner microchemical reagents, 
together with their method of preparation and chief uses. For fuller 
details in this branch of the subject the reader is referred to Poulsen's 
Botanical Microchemistr)^, translated by Trelease, and Zimmerman's 
Botanical Microtechnique. 

A. Analytical Reagents. — Iodine in Potassium Iodide. — Two grams 
of cr)'stallized potassium iodide are first dissolved in 100 cc. of distilled 
water and the solution is saturated with iodine. 

This reagent is indispensable for the identification of starch, especially 
when the latter is present in minute quantities. Starch granules when 
moistened with water are turned blue by iodine, the reaction being exceed- 
ingly delicate under the microscope, even when the starch granules are 
very minute and insignificant without the reagent. 

Iodine in connection with sulphuric acid is also useful in distinguishing 
pure cellulose from its various modifications, such as lignin and suberin. 
For this purpose the water-mounted sample is first permeated with the 
iodine reagent, after which concentrated sulphuric acid is applied, with 
the result that all pure cellulose is turned a deep-blue color, while the 
modified forms of cellulose are colored yellow or brown. The cellulose 
is first converted by the sulphuric acid into a carbohydrate isomeric with 
starch, known as amyloid. 

Protein grains are colored brown or yellow brown by the action of 
iodine. 

Chloriodide of Zinc. — Pure zinc is dissolved in concentrated hydro- 
chloric acid to saturation, and an excess of zinc added. The solution is 
then evaporated to about the consistency of concentrated sulphuric acid, 
after which it is first saturated with potassium iodide, and finally vdth 
iodine. 

This reagent may be used instead of sulphuric acid and iodine for the 



92 FOOD INSPECTION AND ANALYSIS. 

detection of cellulose, since the zinc chloride converts the cellulose into 
amyloid, which the reagent colors blue. 

Chloriodide of zinc is useful for detecting tannic acid in cell contents. 
For this purpose the above reagent is much diluted by the addition of 
a 20% solution of potassium iodide. In this diluted form, when applied 
to the sami^le, a reddish or violet coloration is imparted to cell contents 
having tannin. 

Phenol-hydrochloric Acid is prepared by saturating concentrated 
hydrochloric acid with the purest crystallized carbolic acid. Wood fiber, 
or lignin, when treated with a drop of this reagent under the cover-glass, 
and exposed for half a minute to the direct sunlight, will be colored an 
intense green, which quickly fades. 

Indol. — Several crystals of indol are freshly dissolved in warm water. 
Lignified cell walls assume a deep-red color, when the specimen to be 
examined is treated first with a drop of the indol reagent, and afterwards 
washed with dilute sulphuric acid, i : 4. 

Milloti^s Reagent. — This is prepared by dissolving metallic mercury 
in its weight of concentrated nitric acid, and diluting with an equal volume 
of water. This reagent, which should be freshly prepared, is of use in 
testing for protein compounds, which turn brick red when treated with it, 
especially on gently warming the slide. 

Tincture 0} Alkanna. — A 70 or 80% alcoholic extract of alkanna root, 
when kept in contact with resins, fixed oils, fats, or essential oils for a 
short time, stains these cell contents a lively red. The staining is hastened 
by the aid of heat. Essential oils and resins are soluble in strong alcohol, 
while fixed oils and fats are insoluble, hence the distinction between these 
classes of cell contents may be made by the application of alcohol to the 
alkanna-stained specimen. 

Ferric Chloride, Ferric Acetate, or Ferric Sulphate, used in dilute aqueous 
solution, are all applicable as reagents for tannic acid, which, when present 
in appreciable amount, will be colored green or blue by either of these 
reagents. 

B. Clarifying Reagents. — Many of the harder cellular tissues are too 
opaque for careful examination, and maybe rendered transparent by clarify- 
ing or bleaching. A portion of the powdered sample is either treated 
with a drop of the reagent under the cover-glass or is allowed to soak 
for hours or even days in the reagent, using a drop of the same reagent 
as a medium for examination on the object-glass, instead of water. 
The clarifying reagents most commonly used are the following: 



THE MICROSCOPE IN FOOD /ANALYSIS, 



93 



Chloral Hydrate. — \ 60% solution. 

Ammonia. — Concentrated, or 28% ammonia is commonly used. 

Potassium Hydroxide, used in various degrees of concentration, often 
in dilute solution, say 5%. This reagent, added to a water mount, 
causes swelling of the cell wall, and dissolves intercellular substances 
and protein. It bleaches most of the coloring matters, destroys the 
starch, and forms soluble soaps with the fats. Potassium hydroxide is 
also used in testing for suberin, which is extracted from corky tissue 
on boiling with the reagent, and appears as yellow drops. 

Schultze's Macerating Reagent (concentrated nitric acid and chlorate of 
potassium) is best used by placing the powder or bit of tissue to be treated 
in a test-tube with an equal volume of potassium chlorate crystals, adding 
about 2 cc. of concentrated nitric acid, and warming the tube till bubbles 
are evolved freely, or until the necessary separation of cells is effected. 
The sample is then removed and washed with water. 

By this treatment, bast and wood fibers as well as stone cells are 
readily separated from other tissues. 

Cuprammonia (Schweitzer's Reagent). — This is prepared by adding 
slowly a solution of copper sulphate to an aqueous solution of sodium 
hydroxide, forming a precipitate of cupric hydroxide, which is separated 
by filtration, washed, and dissolved in concentrated ammonia. It should 
be freshly prepared, and is never fit for use unless it is capable of immediately 
dissolving cotton. Indeed its cliief use is as a test for cellulose, which it 
readily dissolves. In observing this reaction under the microscope, the 
powdered specimen under the cover-glass should be only slightly damp 
before a drop of the fresh reagent is applied. The cell walls are seen to 
swell up and gradually become more and more indistinct, till they finally 
disappear. 

Cuprammonia is also used as a test for pectose, which occurs in many 
cell walls, often intermixed with cellulose. \Vhen treated with this reagent, 
cellular tissue containing pectose is acted upon in such a manner that 
a delicate framework of cupric pectate is sometimes left behind, after the 
dissolution of the cellulose with which it is mingled.* 

PHOTOMICROGRAPHY. 

The photomicrograph serves as a simple means of keeping perma- 
nent records of unusual forms of adulteration encountered in the course 
of routine examination. Besides this, the photomicrograph has at 
times proved its usefulness as a means of evidence in court, showing as it 
does with faithfulness the presenc e of a contested adulterant. It is true 

* Poulsen, Botanical Micro-chemistry, p. 15. 



94 



FOOD INSPECTION /IND /IN ^ LYSIS. 



that from an artistic standpoini the photomicrograph of a powdered 
sample is often disappointing, due to the fact that ordinarily much of the 
field is out of focus, unless a very simple homogeneous subject is photo- 
graphed, as, for instance, starch. As compared with the carefully prepared 
drawing of a section, which is usually idealized, the photomicrograph is 
in a sen.se the more truthful representation, 

SUMMARY OF MICROCHEMICAL REACTIONS FOR IDENTIFYING 
CELLULAR TISSUE AND CELL CONTENTS. BASED ON BEHRENS'.* 





Iodine in 

Pi itassium 

Iodide. 


_ Chlor- 

iodide of 

Zinc. 


Iodine 
and Sul- 
phuric 
Acid. 


Cupram- 
monia. 


Potassium 
Hydroxide. 


Concen- 
trated 
Sulphuric 
Acid. 


Schultze's 
Mixture. 


Cellulose, cell substance. 

Lignin, wood substance. 

Middle lamella, inter- 
cellular substance. . . . 


Yellow to 

brownish 

Yellow 

Yellow 

Yellow or 
brownish 

Blue 
Brown 
yellow 


Violet 

Yellow 

Yellow 

Yellow or 
brown 


Blue 

Yellow to 
brownish 

Yellow 

Brown 


Dissolves 

Insoluble 

Insoluble 
Insoluble 


Swells up 
Dissolves 


Dissolves 

Dissolves 


Dissolves 

Dissolves 
easily 


Suberin, cork substance. 
Starch 


Insoluble 

in cold. 

By boiling 

it comes out 

in drops 

Dissolves 

Dissolves 


Insoluble 


easily 
Gives 
eerie 
acid reac- 
tiont 


























Fat 










Saponifies 
























Reddish 
to violet 












Calcium oxalate crystals 















































Phenol- 
hydro- 
chloric 
Acid. 


Indol. 


Ferric 

Acetate 
or Sul- 
phate. 


Alkanna 
Tincture. 


Hydro- 
chloric 
Acid. 


Acetic 
Acid. 


Millon's 
Reagent. 




Uncolored 
Green 

arppn 


Uncolored 

Cherry 

red 

Cherry 

red 

Uncolored 












Lignin, wood substance. 
Middle lamella, inter- 








































































Bright red 
Bright red 
Bright red 








Fat . 


































Blue or 
green 








Calcium oxalate crystals 








Soluble 
without ef- 
fervescence 

Soluble 
with effer- 
vescence 


Insoluble 

Soluble 
with effer- 
vescence 































* Microscopical Investigation of Vegetable Substances, page 356. 

t When treated with the reagent, suberin forms masses of eerie acid, soluble in ether, alcohol, or 
chloroform. 

While the analyst examines microscopically the ordinary powdered 
spice, for example, he constantly moves with his hand the fine adjustment- 
screw, bringing into focus different parts of the field successively. This 



THE MICROSCOPE IN FOOD ANALYSIS. 05 

he does unconsciously, so that he does not realize how far from flat the 
field actually is till he undertakes to photograph it, when, as a rule, only 
a small portion is in good focus. It is therefore impossible in one photo- 
graph to show successfully many varied forms of tissue or cell contents 
in the powder, but separate photographs should be made as far as possible 
\nth only a little in each. Thus, for example, with a composite subject 
like powdered cassia bark, it would be ver\^ difficult to show starch, stone 
cells, and bast fibers in one field, all in equally good focus, and, for the best 
results only, one, or at most two, such varied groups of elements should be 
shown in one picture. 

Appurtenances and Methods of Procedure. — The temporar}^ method 
of water-mounting employed by the analyst in routine examination pre- 
sents many difficulties from a photographic point of view. The vibrating 
motion of the particles is very annoying, and some skill is required in using 
just the right amount of water, in avoiding air-bubbles, in waiting the 
requisite amount of time before exposing the plate for the vibratory motion 
to cease, and, on the other hand, avoiding too long delay, which would 
result in the evaporation of the water, and the consequent breaking up of 
the field. In the writer's experience, how^ever, in spite of these difficulties, 
the water-mounting gives decidedly the clearest results, and, with patience 
on the part of the operator, it is in many ways the most desirable method of 
mounting for photographic purposes. It is in fact the method employed in 
making most of the photomicrographs of powdered specimens that appear 
in the plates at the end of this volume, though a few were mounted in 
glycerin jelly, and the starches for the polarized-light pictures in Canada 
balsam. The sections of tissues shown in the plates were mounted some 
in glycerin and others in glycerin jelly. 

Experience has shown that two degrees of magnification w-ell cal- 
culated to bring out the chief characteristics of the spices and their adul- 
terants in a photomicrograph are 125 and 250 diameters. The starches, 
which are the most common of any one class of adulterants, vary very 
widely in the size of their granules. With these the larger magnification 
of 250 has been found satisfactor)'. while the general appearance of the 
composite ground-spice itself under the microscope, as w^ll as that of 
such adulterants as ground bark, sawdust, chicor)^, pea hulls, and the 
like, is best shown with the lower power of 125.* 

* The degrees of magnification adopted in the originals of most of the photomicrographs 
illustrated in the accompanying plates are accordingly 125 and 250, but in the process of 
lithographing, the photographs were slightly reduced, so that the actual scales in the repro- 
duction are no and 220 respectively. 



96 



FOOD INSPECTION AND ANALYSIS. 



The object, mounted in the manner above described, is best examined 
when held in a mechanical stage, furnished with micrometer adjust- 
ments, in such a manner that a typical field may be selected and held 
in place long enough to photograph. 

The Camera. — This need not of necessity be complicated, but may 
consist simply of a horizontal wooden base on which the microscope 




Fig 35«. — A Convenient Photomicrographic Camera. 

rests, and an upright board firmly secured to the base, carrying a frame 
for an interchangeable ground glass and plate-holder, with a rubber 
gauze skirt hanging from the frame, adapted to be gathered and tied 
about the top of the microscope-tube. IMeans are further provided, as 
by a slotted guide and screw, for adjusting the frame at any desired height 
on the upright board.* 

A more convenient form of apparatus now employed by the writer is 
that shown in Figs. 35a and 356. 

* Such a contrivance as this was employed in making some of the accompanying photo- 
micrographs. 



THE MICROSCOPE IN FOOD /1N^ LYSIS. 97 

The base is a solid iron plate upon which the microscope rests (any 
microscope may be used with this camera), and above w^hich the camera 
bellows is supported on two solid steel rods. The bellows is supported 
at either end on wooden frames. 

The ground glass is provided with a central transparent area, formed 
by cementing a cover-glass upon the ground glass, and permits the accurate 
focusing of the most delicate detail by means of a hand magnifying-glass. 
The vertical rods supporting the bellows are attached to metal arms, 
immovably fixed to a horizontal axis, thus permitting the camera to be tilted 




Fig 356. — Photomicrographic Camera in Horizontal Position 

to any angle from vertical to horizontal. It is fixed at the desired angle by 
means of hea\y hand-clamps. 

In use the camera is placed in a vertical position and the microscope 
adjusted on the base so that its tube will coincide with the opening in 
the front of the camera. The connection between microscope and camera 
is made light-tight by means of a double chamber, which permits consider- 
able vertical motion of the tube of the microscope without readjustment. 
A jointed telescoping rod is attached to the upper end of the camera to 
act as a support, giving perfect steadiness when in a horizontal position, 
and folding do\\'n parallel with the bellows so as to be out of the way 
when in any other position. 

Amplificaiion. — The vertical rods are graduated in inches for deter- 
mining the amount of amplification, and to show when the ground glass 
is at right angles to the optical axis. The following simple rule for deter- 
mining the amount of amplification will give sufficiently accurate results. 
When photographing without the eyepiece, divide the distance of the 
ground glass from the stage of the microscope in inches, by the focal length 
in inches of the objective used. When photographing with the eye- 
piece, proceed as above and multiply the result by the quotient obtained 
by dividing 10 by the focus in inches of the eyepiece used. 



gS FOOD INSPECTION y4ND ANALYSIS. 

Adjustment and Manipulation. — The microscope can be placed in 
any position desired, and the camera adjusted to it. The bellows can then 
be raised and the microscope used as though no camera were present. 
When an object is to be photographed, the bellows may be slid into posi- 
tion without in any way disturbing the arrangement of light or object, 
the final focusing on the ground glass being effected quickly by means of 
the fine adjustment-screw of the microscope. The exposure having 
been made, observation through the microscope may be continued with- 
out interruption by simply raising the bellows again. 

When a water-mounted specimen is to be photographed, the camera 
and microscope tube should be vertical instead of inclined as shown in 
the cut. 

The camera is best kept in a dark room where the exposures are to 
be made, the source of light being a i6- or 32-candle-power electric lamp, 
preferably provided with a ground-glass bulb. The light from this lamp 
is first carefully centered by moving the reflector of the microscope. 

In making pictures, for instance, of the magnification of 250 diameters, 
the objective, having an equivalent focus of ^ inch, may be used in 
combination with the one-inch ocular, with the ordinary tube length of 
microscope. For a lower power, such as 125 diameters, the same objec- 
tive is employed, but the eyepiece is left out, it being found necessary 
in this case to remove the upper tube of the microscope, which ordinarily 
carries the eyepiece, as otherwise the size of the field to be photographed 
would be restricted. In each case a diaphragm is used in the microscope 
stage, having an opening of about the same size as that of the front lens 
of the objective. By means of a stage micrometer scale, the proper posi- 
tion of the camera back is previously determined to give the required 
magnification. 

REFERENCES ON THE MICROSCOPE IN FOOD ANALYSIS. 

Alltmann. Die Elementarorganismen und ihre Beziehungen zu den Zellen. Leipzig, 

1890. 
Behrens, J. W. Guide to the Microscope in Botany. Translated by Heney. Boston, 

1885. 
Bergen, J. Elements of Botany. Gross and Microscopic Structure. Vegetable 

Histology. 
Bessey, C. E. The Essentials of Botany. 

Botany for High Schools and Colleges. New York, 1880. 

Bonsfield, E. C. Guide to Photomicrography. London. 

Chamberlain, C. J. Vegetable Tissues. 

• Methods in Plant Histology. Chicago, 1905. 



THE MICROSCOPE IN FOOD ^N^ LYSIS. 99 

Cl.\rk, C. H. Practical Methods in Microscopy, 1900. 

Dammar, O. Illustrirtes Lexicon der Verfalschungen und Verunreinigungen der Xah- 
rungs- und Genussmittel. Leipzig, 1886. 

Detmer, W. Das pflanzenphysiologische Praktikum. Jena, 1885. 

DiETSCH, O. Die wichtigsten Xahrungsmittel und Getranke, deren Verunreinigungen 
und Verfalchungen. Zurich, 1884. 

Gage, S. H. The Microscope and Microscopical Methods. Ithaca, 1904. 

Greenish, H. G. The Microscopical Examination of Foods and Drugs. Philadel- 
phia, 1903. 

H.A.NAUSEK, T. F. The Microscopy of Technical Products. Translated by A. L. 
Winton and Kate G. Barber. New York, 1907. 

H.AL'SHOFER, K. Mikroskopische Reaktionen. Braunschweig, 1885. 

Hegler. Histochemische Untersuchungen verholtzer Zellmembranen. Flora, 1890, 
page 31. 

HoFFMEiSTER, T. Die Rohfaser und einige Formen der Cellulose. Landwirtschaftl. 
Jahrbiicher, 1888, page 239. 

Koch, L. Mikrotechnische Mittheilungen. Pringsheim's Jahrbiicher, Bd. XXIV, 
page I, 1892. 

KjtAEMER, H. Botany and Pharmacognosy. Philadelphia, 1907. 

Kr-\us, G. Zur Kentniss der Chlorophyllfarbstoffe. Stuttgart, 1872. 

L.A.NGE, G. Zur Kentniss des Lignins. Zeits. fiir physiologische Chemie. Bd. XIV, 
page 15. 

Leach, A. E. Microscopical Examination of Foods for Adulteration. An. Rep. 
Mass. State Board of Health, 1900, p. 679. 

Lee, a. B. The Microtomist's Vade Mecum. 1893. 

Mace, E. Les Substances Alimentaire Etudies au Microscope. Paris, 1891. 

MoELLER, J. Mikroskopie der X'ahrungs- imd Genussmittel aus dem Pflanzenreiche. 
Berlin, 1905. 

Pharmacognostischer Atlas. Berlin, 1892. 

Molisch. Grundriss einer Histochemie der pflanzlichen Genussmittel. Jena, 1891. 

Xeuh-AUSS, R. Lehrbuch der Mikrophotographie. Braunschweig, 1890. 

PouLSEN, V. A. Botanical Microchemistr)-, translated by Trelease. Boston, 1886. 

Pringle, a. Practical Photomicrography. Xew York, 1890. 

ScmMPER, A. F. W. Mikroskopischen L'ntersuchungen der Xahrungs- und Genuss- 
mittel. Jena, 1900. 

SxRASSBURGER, E. Manual of \'egetable Histology, translated by Her\ey. 1887. 

Thomas and Dudley. A Laboratory' Manual of Plant Histolog}-. 

TscHiRCH, A., und Oesterle, O. Anatomischer Atlas der Pharmakognosie und X'ahr- 
ungsmittelkunde. Leipzig, 1900. 

\'OGL, A. E. Die wichtigsten vegetabilischen Xahrungs- und Genussmittel. Berlin, 1899. 

WiNSLOW, C E. A. Elements of Applied Microscopy. Xew York, 1905. 

WiNTON, A. L. The Microscopy of Vegetable Foods. Xew York, 1906. 

WoRMLEY, T. G. The Microchemistrj' of Poisons. Philadelphia, 1885. 

ZiiiMERM.^N, A. Botanical Microtechnique. Xew York, 1893. 

Die Morphologie und Physiologie der Pflanzenzelle. Breslau, 1887. 

Beitrage zur Morphologie und Physiologie der Pflanzenzelle. Tubingen, 1890. 



CHAPTER Vr. 

THE RKFRACTDMETRR. 

The refractive index ranks in imj)orlance with the specific gravity 
as a means of determining the identity and purity of various food 
])roducts, as well as of estimating the percentage of valuable constituents. 
Various forms of refractomeler are used in food analysis. 

The Abbe rcfraclomeler is of general a])plication in determining 
the refractive index of fats, fatty oils, waxes, and essential oils, in esti- 
mating the solids m saccharine substances, and in other analytical opera- 
tions. It em[)loys but a few dro])s of the material, and reads the refractive 
index directly, using ordinary white light. 

The immersion rrfrac/omeler, an instrument of recent introduction, 
is suited for the examination of milk serum to detect added water 
therein, the detection and determination of methyl alcohol in ethyl 
alcohol, and the standardization of a wide variety of solutions. The 
instrument is immersed directly in liic lic|uid to be examined, the degree 
of refraction being indicated on an arbitrary scale. 

The Pulfrich is used with the sodium light, and requires a larger 
amount of material tiian the Abbe, the li(|uid being hekl in a cylinder 
above the prism. The scale reading is in angular degrees, from which 
the index of refraction is calculated by a formula or from a table. The 
instrument is ])rovided with a temj)erature-controlling api)aratus. 

In ihe Amagal ami Jean or oleo-rrfrae/ome/er, an outer and an inner 
cylinder are resjjectively filled with an oil of known value or i)urity, and 
with the oil to be examined. By the comparative displacement to the 
right or left of a Ix'am of white light ])assing llirougli l)oth cylinders, the 
displacement being read in degrees on an arbitrary scale, the refraction 
of an oil may be measured. Two oils may thus be readily compared 
under the same conditions, one of known purity, for example, with a 
doubtful sample of tlie same kind. 

The bulyro-refraelometer and the Wollny milk fat refractomeler are, 
as their names imply, instruments ])rimarily intended for more restricted 
ilelds of work than the foregoing. They involve the same principle as 
lac Abb^, but are simj)ler in construction and have arbitrary scales. 

Unless such widely varying substances as the waxes and the essential 
oils arc to be studied, the Zeiss butyro-refractometer, though j)rimarily 



IHR REFRACT OMETF.R. 



lOI 



intended for the examination of butter and lard, answers most of the 
purposes of the Abbe instrument with the advantage of greater sim- 
phcity, being equally well adapted for examining all the common edible 
oils and fats, as well as other materials. 

THE ZEISS BUTYRO-REFRACTOMETER. 

This instrument (shown in Fig. 36) is so constructed that the degree 
of refraction of a beam of light, which passes oblicjuely through a thin 




Fin. 36. — Tht Zeiss Butyro-refractometer. 

film of the fat, is read on an arbitrary scale of sufficient extent to cover 
the widest limits of deviation possible for butter fat and oleomargarine 
under ordinary temperatures. 

The graduation is in divisions from i to 100, covering a variation in 
refractive indices of from 1.4220 to 1.4895. A and B are the two hinged 
hollow portions of the prism casing of the instrument, so arranged that 
when closed together the melted fat is held in a film of sufficient thickness 
between the two opposed transparent prism surfaces, the beam of light, 
cither diffused daylight or lamplight, being reflected through it by means 
of the mirror /. The transparent scale is within the telescope tube at 
the height indicated by G. 



I02 FOOD INSPECTION /1ND ANALYSIS. 

The refractometer is connected to any kind of heating arrangement, 
which admits of warm water being transmitted through the prism casing, 
in at D and out at E. A simple arrangement, which suffices for all 
ordinary cases, may expeditiously be improvised in the following manner: 
Fill a vessel of say 2 gallons capacity with water of 40° to 50° C. Into 
this vessel dip the free end of an india-rubber tube slipped over the nozzle 
D and let the vessel be placed at a height of about one-half or one yard 
above the refactometer. Then it will be seen that suction at a tube 
attached to E will cause the warm water to flow through the prism casing 
by the action of the siphon arrangement. By means of a pinch clip the 
velocity of the water may be regulated at will. The waste water 
may be allowed to flow into a second vessel and, provided its tem- 
perature does not fall below 30°, it may be used for replenishing the 
upper vessel. 

When working with solid fats, a temperature must be maintained 
by the heated water wefl above the mehing- point of the fat. With 
liquid oils no heater is necessary, as determinations may be made at 
room temperature, but it is advisable in all cases to have a constant stream 
of water passing through the water jacket, which may be done by directly 
connecting it witJi the water faucet in the case of oils, since, without such 
precautions to insure even temperature, disturbing variations are liable 
to occur, due to the warming of the prisms by the manipulation of clean- 
ing, etc. 

Refractometer Heater. — A regular heater, shown in Fig. 37, is furnished 
by the manufacturers, capable of supplying a current of water of approx- 
imately constant temperature, and wiU be found of great convenience when 
the instrument is to be used constantly, especially with the solid fats. 

A supply reservoir A is secured to the wall and is connected by means 
of a rubber inlet tube G to the water faucet C. The reservoir is provided 
with a waste overflow pipe and with an outlet tube D, the flow through 
the latter being regulated by the cock H. The tube D leads to the spiral 
heater HS, which is heated by a Bunsen burner. From the heater the 
tube E conducts the warm water through the refractometer, from which 
it flows through the tube F, either directly into the sink, or into the inter- 
mediate vessel B. The temperature of the water is regulated by adjust- 
ing the cock H, and the height of the flame of the Bunsen burner. 

Manipulation of the Butyro-refractometer. — The prism casing is first 
opened by giving about half a turn to the right to the pin F, Fig. 7,6, 
until it meets with a stop. Then simply turn the half B of the prism 



THE REFRACTOMETER. 



103 



casing aside. Pillar // holds B in the position shown in Fig. 36. The 
prism and metallic surfaces must now be cleaned with the greatest care, 
the best means for this purpose being soft linen, moistened with a little 
alcohol or benzine. 

If the sample to be examined is a solid fat, maintain the temperature 
above the melting-point_, and apply by a glass rod a drop or two of the 
clear mehed fat (filtered if turbid) to the surface of the prism contained 
in the casing B. For this purpose the apparatus should be raised with 




Fig. 37.— The Zeiss Heating Apparatus for all Forms of Refractometer. Shown in the 
cut in connection with the Pulfrich refractometer. 

the left hand so as to place the prism surface in a horizontal position. 
A liquid oil is directly applied in the same manner without preliminary 
precautions as to heating. Now press B against A, and place F by 
turning it in the opposite direction, in its original position; thereby B 
is prevented from falling back,, and both prism surfaces are kept in close 
contact. Place the instrument again upon its sole plate. 

While looking into the telescope, give the mirror / such a position as 
to render the critical line, which separates the bright left part of the field 
from the dark right part, distinctly visible. It may also be necessary 
to move or turn the instrument about a little. First it will be necessary 
to ascertain whether the space between the prism surfaces be uniformly 
filled with oil or fat, failing which the critical line will not be distinct. 
For this purpose examine the rectangular image of the prism surface 
formed about i cm. above the ocular with a hand magnifier or with the 



IC4 



FOOD INSPECTION AND ANALYSIS. 



naked eye, placing the latter at its proper distance from the ocular. 
Finally adjust the movable front part of the ocular so that the scale 
becomes clearly visible. 

By allowing a current of water of constant temperature to flow through 
the apparatus some time previous to the taking of the reading, the at lirst 
somewhat hazy critical line approaches in a short time, generally after a 
minute, a fixed position, and quickly attains its greatest distinctness. 
When this point has been reached, note the appearance of the critical 
line (i.e., whether colorless or colored, and in the latter case of what color); 
also note the position of the critical hne on the centesimal scale, which 
admits of the tenth divisions being conveniently estimated; at the same 
time read the position of the thermometer. 

Testing the Adjustment of the Ocular Scale. — It is imperative that 
the adjustment of the instrument be tested periodically, and in particular 
when it is being used for the first time. This may be done by means 
of the standard fluid supplied with the instrument, the critical line of 
which is approximately colorless, and must occupy the following positions 
in the scale. 



Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


30= 


68.1 


25° 


71.2 


20° 


74-3 


15° 


77-3 


29° 


68.7 


24° 


71-8 


19° 


74-9 


14° 


77-9 


28° 


69-3 


230 


72.4 


18° 


75-5 


13° 


78.6 


27° 


70.0 


22° 


73-0 


17° 


76.1 


12° 


79-2 


26° 


70.6 


21° 


73-6 


16° 


76.7 


11° 


79-8 


25' 


71.2 


20° 


74-3 


15° 


77-3 


10° 


80.4 



The fractional parts of a degree can accordingly easily be brought 
into calculation (0.1=0.06 scale div.). Deviations of i to 2 decimals 
of the scale divisions are of no consequence, and are in most cases due 
to inexact determinations of temperature. Should, however, careful 
tests result in the discovery of greater deviations, readjustment of the 
scale will be necessary, which may be effected by means of a watch-key 
supplied with the instrument, in accordance with the values given in 
the above table. The watch-key is inserted at G in Fig. 36, and by its 
means the position of the objective, and therefore that of the critical line 
with respect to the scale may be altered. 

Transjormation 0} Scale Divisions into Indices of Refraction. — The 
following table, adapted from that of Pulfrich, enables one to convert 
scale readings on the butyro-refractometer into indices of refraction, w^, 
and vice versa: 



THE REFRACrOMElER. 



105 



EQUIVALENTS OF INDICES OF REFRACTION AND BUTYRO-REFRAC- 

TOMETER READINGS. 



Fourth Decimal of n^j 



SCALE READINGS. 



1.2 

2-5 

3-7 
5-0 
6.2 

7-5 
8.7 

10. 
II-3 
12.5 
13-8 

I5-I 
16.4 
17.8 

19. 1 
20.4 
21.7 

23.0 

24-3 
25.6 
27.0 
28.3 
29.7 
31-1 
32-5 
33-9 
35-3 



36-7 
38.1 

39-5 
40.9 

42.3 
43-7 
45-2 
46.6 
48.0 
49-5 

51.0 

52-5 
54-0 
55-6 
57-1 
58-6 
60.2 
61.7 
63.2 
64.8 



0.1 

1-4 
2.6 



6.4 
7.6 

8.9 

10. 1 
II. 4 
12.7 
14.0 

16.6 
17.9 
19.2 
20.5 
21.8 

23.2 

24-5 
25.8 
27.1 
28.5 

29-9 
31.2 
32.6 
34-0 
35-4 

36. 8 
38-2 
39-6 
41.0 
42.4 
43-9 
45-3 
46.7 
48.2 

49-7 



52-7 
54-2 
55-7 
57-3 
58.8 
60.3 
61.8 

63-4 
65.0 



2.7 
4.0 
5-2 
6-5 
7-7 
9.0 



10.3 

"-5 
12.8 

14. 1 
15-4 
16.7 
18.0 

19-3 
20.6 
22.0 

23-3 
24.6 

25-9 

27-3 
28.6 
30.0 
31-4 

:2.8 
34-2 
35-6 

37-0 
38.3 
39-7 
41. 1 

42.5 
44-0 

45-5 
46.9 

48.3 
49-8 

51-3 
52.8 

54-3 
55-9 
57-4 
58.9 
60.5 
62.0 

63-5 
65.1 



0.4 
1.6 
2.8 
4-1 
5-4 
6.6 

7-9 
9-1 

10.4 
II. 6 
12.9 

14.2 

15-5 
16.8 
18.2 

19-5 
20.8 
22.1 



23-4 
24.7 
26.1 

27-4 

■7 



28. 
30- 
31' 
32- 
34. 
35- 



37-1 
38.5 
39-9 
41-3 
42.7 

44-2 
45-6 
47.0 

48.5 
50.0 

51-4 
53-0 
54-5 
56.0 

57-6 

59-1 
60.6 
62.2 
63-7 
65-3 



0-5 


0.6 


0.7 


0.9 


i.o f 


1-7 


1.9 


2.0 


2.1 


2-2 ; 


3-0 


3-1 


Z-^ 


2>-l 


3-5 


4-2 


4-3 


4-5 


4-6 


4-7 


5-5 


=;.6 


5-7 


5-9 


6.0 


6.8 


6.9 


7.0 


7-1 


7-2 


8.0 


8.1 


8.2 


8.4 


8-5 


9-2 


9-4 


9-5 


9.6 


9-8 


10-5 


10.6 


10.7 


10.9 


II. 


II. 8 


II. 9 


12.0 


12.2 


12.3 


13.0 


13-2 


13-3 


13-5 


13-6 I 


14-4 


14-5 


14.6 


14-7 


14-9 


15.6 


15.8 


15.9 


16.0 


16.2 


17.0 


17. 1 


17.2 


17-4 


17-5 


18.3 


18.4 


18.5 


18.7 


18.8 


19.6 


19.7 


19-8 


20.0 


20.1 


20.9 


21. 1 


21.2 


21.3 


21.4 


22.2 


22.4 


22.5 


22.6 


22.7 


23-5 


23-7 


23.8 


23-9 


24.1 


24.8 


25.0 


25-1 


25.2 


25-4 


26.2 


26.3 


26.5 


26.6 


26.7 


27-5 


27-7 


27.8 


27.9 


28.1 ' 


28.9 


29.0 


29.2 


29-3 


29.4 


30-3 


30-4 


30.6 


30-7 


30-8 


31.6 


31.8 


31-9 


32.1 


32.2 


33-0 


33-2 


33-3 


33-5 


33-6 


34-4 


34-6 


34-7 


34.9 


35-0 


35-8 


36.0 


36.1 


36.3 


36.4 : 


37-2 


37-4 


37-5 


37-7 


37-8 


38.6 


38.7 


38-9 


39-0 


39-2 


40.0 


40.1 


40.3 


40.4 


40.6 : 


41.4 


41-5 


41-7 


41.8 


42-0 1 


42.8 


43-0 


43-1 


43-3 


43-4 i 


44-3 


44-4 


44-6 


44-7 


44-9 ' 


45-7 


45-9 


46.0 


46.2 


46-3 


47-2 


47-3 


47-5 


47-6 


47-7 


48.6 


48.8 


48.9 


49-1 


49-2 


50.1 


50.2 


50-4 


50-S 


50-7 


51.6 


51-7 


51-9 


52.0 


52.2 


53-1 


53-3 


53-4 


53-6 


53-7 ' 


54-6 


54-8 


55-0 


55-1 


55-3 , 


56.2 


56-3 


56-5 


56.6 


56-8 i 


57-7 


57-9 


58.0 


58.2 


58-3 


59-2 


59-4 


59-5 


59-7 


59-8 


60.8 


60.9 


61. 1 


61.2 


61.4 


62.3 


62.5 


62.6 


62.8 


62.9 


63-8 


64.0 


64.2 


64-3 


64.5 


65-4 


65.6 


65-7 


65-9 


66.1 



I.I 

2.4 

3-6 
4-8 
6.1 

7-4 
8.6 

9-9 

XI. I 

12.4 

13-7 
15-0 
16.3 
17.6 
18.9 
20.3 
21.6 
22. g 

24.2 

25-5 
26.9 

28.2 
.6 
9 
3 
7 
I 



29 
30 ■ 
32. 
iZ- 
35- 
36.5 

37-9 
39-3 
40.7 
42.1 
43-6 
45-0 
46.4 
47-9 
49 4 
:;o.8 



52-3 
53-9 
55-4 
56-9 
58.5 
60.0 
61.5 
63.1 
64.7 
66.2 



io6 




FOOD INSPECTION yIND ANALYSIS. 








EQUIVALENTS OF 


INDICES OF 


REFRACTION AND 


BUTYRO-REFRAC- 






TOMETER READINGS— (CoM/iMMe<i). 








Refrac- 






Fourth Decimal of w/)_ 






tive 


















Index. 






• 1 














*tD. 





1 


2 3 


4 


5 


6 


7 


8 


9 








SCALE READINGS 










1.470 


66.4 


66.5 


r-6.7 


66.8 


67.0 


67.2 


67-3 


67-5 


67.7 


67.8 


1. 471 


68.0 


68.1 


68.3 


68.4 


68.6 


68.7 


68.9 


69.1 


69.2 


69.4 


1.472 


69-5 


69.7 


69.9 


70.0 


70.2 


70-3 


70-5 


70.7 


70.8 


71.0 


1-473 


71. 1 


71-3 


71.4 


71.6 


71.8 


71.9 


72.1 


72.2 


72-4 


72.5 


1-474 


72.7 


72.9 


73-0 


73-2 


73-3 


73-5 


73-7 


73-8 


74.0 


74-1 


1-475 


74-3 


74-5 


74.6 


74.8 


75 -o 


75-1 


75-3 


75-5 


75-6 


75-8 


1.476 


76.0 


76.1 


76-3 


76-5 


76-7 


76.8 


77.0 


77-2 


77-3 


77-5 


1-477 


77-7 


77-9 


78.1 


78.2 


78-4 


78.6 


78-7 


78.9 


79-1 


79-2 


1.478 


79-4 


79-6 


79-8 


80.0 


So. I 


80.3 


80.5 


80.6 


80.8 


81.0 


1.479 


81.2 


81.3 


81.5 


81.7 


81.9 


82.0 


82.2 


82.4 


82.5 


82.7 


1.480 


82.9 


83.1 


83-2 


83-4 


83-6 


83.8 


83-9 


84.1 


84-3 


84-5 


1-481 


84.6 


84.8 


8s. 


85-2 


85-3 


85-5 


85-7 


85-9 


86.0 


86.2 


1.482 


86.4 


86.6 


86.7 


86.9 


87.1 


87-3 


87-5 


87.6 


87.8 


88.0 


1.483 


88.2 


88.3 


88.5 


88.7 


88.9 


8g.i 


89.2 


89-4 


89.6 


89.8 


1.484 


90.0 


90.2 


90-3 


90-5 


90.7 


90.9 


91. 1 


91.2 


91.4 


91.6 


1.485 


91.8 


92.0 


92.1 


92-3 


92.5 


92.7 


92-9 


93-0 


93-2 


93-4 


1.486 


93-6 


93-8 


94.0 


94-1 


94-3 


94-5 


94-7 


94-8 


95-0 


95-2 


1-487 


95-4 


95-6 


95-8 


96.0 


96.1 


96-3 


96.6 


96-7 


96-9 


97.0 


1.488 


97-2 


97-4 


97-6 


97.8 


98.0 


98.1 


98.3 


98.5 


98-7 


98-9 


1.489 


99-1 


99-2 


99-4 


99.6 


99-8 


lOO.O 











The Critical Line. — It should be remembered that the instrument is 
primarily intended for use with butter, and that the prisms are so con- 
structed that the critical line of pure butter is colorless, while various other 
fats and oils, notably oleomargarine, which have greater dispersive powers 
than natural butter, show a colored critical line. Wlien too great dis- 
persion is apparent to render possible an accurate reading, or when the 
critical line presents very broad fringes, as with linseed oil, poppyseed 
oil, turpentine, etc., use a sodium light, obtained by the application of 
table salt to the Bunsen gas flame, or the diffused daylight may be re- 
flected in the mirror through a flat bottle filled with a dilute solution of 
potassium bichromate, to give a yellow light. 

The advantages of the refractometer for examination of fats and 
oils consist in the convenience with which ver}^ accurate determinations 
of the refractive index may be made at any temperature between 10° and 
50° C, inclusive of thermal variations of refractive powers, and also in 
the possibility which it affords of distinguishing substances by their 
different dispersive powers, rendered visible by the different coloring 
of the critical line, a red-colored critical line being indicative of a relatively 
low dispersive power, a blue line of relatively high dispersion. 



il 



L 



i-S-t 



THE REFRACT OMETER. 



107 



Variation of Reading with the Temperature.—^ 
No definite temperature has been adopted as a 
standard for readings of this instrument, but it 
is easy to reduce readings at any temperature to 
terms of any other temperature for purposes of 
comparison. While the change in index of re- 
fraction for 1° C. is the same whatever the 
temperature, as Tolman and Munson have pointed 
out,* the change in scale reading per 1° C. de- 
creases as the temperature increases, and varies 
slightly with different oils. For correcting read- 
ing R' at a temperature T^ to a reading R at 
temperature T, their formula is R = R' — X{T — 
T'), X being the change in scale reading due to 
change of 1° C. in temperature. 

For butter, oleomargarine, beef tallow, lard, 
and other fats reading from 40° to 50° or there- 
abouts on the scale, X = o.55. For oils reading 
between 60° and 70°, like olive, mustard, rapeseed, 
cottonseed, peanut, etc., X = 0.58, and for oils read- 
ing between 70° and 80°, like corn oil, X = o.62. 

The slide rule f shown in Fig. 38, for use with 
the refractometer, has been jointly devised by H. 
C. Lythgoe and the writer, to render unnecessary 
the use of tables or formulas. The extreme upper 
and lower scale divisions indicate indices of re- 
fraction, and adjacent to these are the scale 
divisions indicating readings on the butyro- 
refractometer. By comparison, therefore, the 
values of either the Abbe or the butyro scale 
may be readily ascertained in terms of the 
other. 

The sliding scale, expressing temperature 
readings in degrees centigrade, is intended to be 
used in connection with the adjacent scale of 
butyro-refractometer readings, to readily express 
the butyro-scale reading of any fat or oil taken 
at a given temperature, in terms of that at any 
other temperature. This is frequently convenient 



Fig, 



38. — Comparative 
fractometer Scale. 



* Jour. Am. Chem. Soc, XXIV, p. 755. 
t Manufactured by Messrs. Baird and Tatlock, Ltd., 14 Cross Street, Hatton Garden, 
London. 



io8 



FOOD INSPECTION AND ANALYSIS. 



in comparing the work of various observers, where different temperatures 
have been employed. 

The correction for change in n^ on the scale is 0.000365 for 1° C, 
being based on the experimental work of Tolman, Long, Proctor, Lythgoe, 
and the author. 

THE ABBE REFRACTOMETER. 

This instrument, Fig. 39, has a much wider range in reading than 
either the butyro or the Wollny instruments already described, read- 




FiG. 39. — The Abbe Refractometer with Temperature-controlled Prisms. 



ing as it docs to the fourth decimal between the limits of 1.3 and 1.7 in 
indices of refraction. The equivalent readings of the Wollny milk fat 
refractometer, in indices of refraction, range from 1.3332 to 1.4220, while 
those of the butyro instrument run from 1.4220 to 1.4895. The Abbe 
instrument is thus necessary for use with the high-refracting essential 



THE REFRACT OMETER. 109 

oils. Its construction is such that the prisms can withstand a higher 
heat than in the case of the butyro-refractometer, and it is hence better 
adapted for the examination of samples having a high melting-point, 
such as beeswax and paraffin. An advantage of the Abbe over the butyro 
instrument lies in the fact that the wide dispersion, inevitable when read- 
ing many substances on the butyro, may be entirely compensated for with 
the Abbe, and a clear sharp line be obtained. The construction of the 
prisms in relation to the heating jacket is similar in both instruments, 
and a film of the substance to be examined is held in the same manner 
between the surfaces of the prisms. 

Construction and Manipulation. — The Abbe refractometer is mainly 
composed of the following parts (see Fig. 39) : 

1. The double Abbe prism AB, which contains the fluid and can 
be rotated on a horizontal axis by means of an alidade. 

2. A telescope OF for observing the border-hne of the total reflec- 
tion which is formed in the prism. 

3. \ sector S, rigidly connected with the telescope, on which divisions 
representing refractive indices are engraved. 

The double prism {AB, Fig. 39) consists of two similar prisms of 
flint-glass, each cemented into a metal mount and having a refractive 
index W£)=i.75. The former of the two prisms, that farthest from the 
telescope, which can be folded up or removed, serves solely for the 
purpose of illumination, while the border-line is formed in the second flint 
prism. A few drops of the fluid to be investigated is deposited between 
the two adjoining inner faces of the prisms in the form of a thin stratum, 
about 0.15 mm. thick. 

The double prism is opened and closed by means of a screw-head 
V, which acts in the manner of a bayonet catch. In order to apply a 
small quantity of fluid to the prisms without opening the casing, the 
screw V is slackened and a few drops of fluid poured into the funnel- 
shaped aperture of a narrow passage, not seen in the figure. On 
again tightening the screw, the fluid is distributed by capillary action 
over the entire space between the two prisms. This arrangement facili- 
tates the investigation of rapidly evaporating fluids, such as ether solu- 
tions. In the case of viscous fluids (resins, etc.), a drop of moderate size 
is applied with a glass rod to the dufl prism surface, the double prism 
being opened for the purpose. The prisms are then closed again, and 
before the measurement is proceeded with, the refractometer is left 
standing for a few minutes in order to compensate for any cooling or 
heating of the prisms which might occur while they were separated. 



no FOOD INSPECTION AND AN/ILYSIS. 

The arrangement for controlling the temptTature of the prisms of 
the Abbe refractometer is essentially after Dr. R. Wollny's j)lan of enclos- 
ing the prisms in a metal casing with double walls, through which water 
of a given temi)erature is circulated. 

The border-line is brought within the field of the telescope OF by 
rotating the double prism by means of the alidade in the following 
manner: Holding the sector, the alidade is moved from the initial 
position at which the index ])oints to «/;=i.3, in the ascending scale of 
the refractive indices until the originally entirely illuminated field of 
view is encroached upon from the direction of its lower half by a dark 
portion; the line dividing the bright and the dark half of the field then 
is the "border-line." When daylight or lamplight is being employed, 
the border-line, owing to the total reflection and the refraction caused 
by the second ])rism, assumes at first the appearance of a band of color, 
which is cjuite unsuitable for any exact process of adjustment. The 
conversion of this band of color into a colorless line sharply dividing 
the bright and dark ])ortions of the field is the work of the compen- 
sator, which consists of two similar Amici prisms of direct vision for 
the D-line, and rotated simultaneously, though in opposite directions, 
round the axis of the telescope by means of the screw-head M. The 
dispersion of the border-line, which api)ears in the telescofje as a band 
of color, can thus be counteracted by rotating the screw-head M till 
the equal but opposite dispersions are neutralized, making the line color- 
less and sharp. 

The border-line is now adjusted upon the point of intersection of 
the crossed lines by slightly inclining the double prism to the telescope 
by means of the alidade. The ])osition of the pointer on the graduation 
of the sector is then read by the aid of the magnifier attached to the 
alidade. The reading suj)ijlies the refractive index «^ of the substance 
under investigation without any computation, and with a degree of 
exactness approaching to within about two units of the fourth decimal. 
Simultaneously, the reading of the scale on the drum of the compensator 
{T in Fig. 39) enables the mean dispersion to be arrived at by means 
of a special table and a short process of computation. 

Influence of Temperature. — As the refractive index of fluids varies 
with their tcmj^erature, it is of importance to know the temperature 
of the fluid contained in the double prism during the process of measure- 
ment. 

If, therefore, it is desired to measure a fluid with the highest degree 
of accuracy attainable with the Abbe refractometer (to within one or 



THE REFRACTG METER. Ill 

two units of the fourth decimal of W£>),it is absolutely necessary to bring 
the fluid, or rather the double prism containing it, to a definite known 
temperature, and to be able to control this temperature so as to keep 
it constant to within some tenths of a degree for a period of several 
hours; hence a refractometer })rincipally required for the investiga- 
tion of fluids must be provided with beatable prisms. 

The type of heater shown in Fig, 37 and described in connection 
with the butyro-refractometer on page 102, is equally adapted for con- 
trolling the temperature of the prisms in the Abbe instrument, the flow 
of water entering at D and passing out at £, Fig. 39. 

THE IMMERSION REFRACTOMETER. 

This form of refractometer is of more recent introduction than the 
others made by Zeiss, and has many features that especially commend it 
to the use of the food analyst. The construction of the immersion refrac- 
tometer is such that, as its name implies, it may be immersed directly in an 
almost endless variety of solutions, the strength of which, within limits, may 
be determined by the degree of refraction read upon an arbitrary scale. 
Thus, for example, the strengths of various acids and of a variety of 
salt solutions used as reagents in the laboratory, as well as of formaldehyde, 
of sugars in solution, and of alcohol, are all capable of determination by 
the use of the immersion refractometer. 

Figure 40 shows the form used by the writer. P is a glass prism 
fixed in the lower end of the tube of the instrument, while at the top of 
the tube is the ocular Oc, and just below this on a level with the vernier 
screw Z is the scale on which is read the degree of refraction of the liquid 
in which the prism P is immersed. The tube may be held in the hand 
and directly dipped in the liquid to be tested, this liquid being contained 
in a vessel with a translucent bottom, through which the light is reflected. 
The preferable method of use is, however, that shown in the cut. 

^ is a metal bath with inlet and outlet tubes, arranged whereby water 
is kept at a constant level. The water is maintained at a constant tem- 
perature by means of a controller of the same type as the refractometer 
heater shown in Fig. 37. In the bath A are immersed a number of 
beakers, containing the solutions to be tested. P is a frame on which is 
hung the refractometer by means of the hook iP, at just the right height 
to permit of the immersion of the prism P in the liquid in any of the 
beakers in the row beneath. Under this row of beakers the bottom of 
the tank is composed of a strip of ground glass, through which light is 
reflected by an adjustable pivoted mirror. 



112 



FOOD INSPECTION AND ANALYSIS. 



The temperature of the bath is noted by a delicate thermometer 
immersed therein, capable of reading to tenths of a degree. 

Returning to the main refractometer-tube, i? is a graduated ring or 
collar which is connected by a sleeve within the tube with a compound 
prism near the bottom, the construction being such that by turning 
the collar R one way or the other the chromatic aberration or dispersion of 
any liquid may be compensated for, and a clear-cut shadow or critical line 
projected across the scale. By the graduation on the collar R, the degree of 





Fig. 40. — The Zeiss Immersion Refractometer. 

dispersion may be read. Tenths of a degree on the main scale of the in- 
strument may be read with great accuracy by means of the vernier screw Z, 
graduated along its circumference, the screw being turned in each case till 
the critical line on the scale coincides with the nearest whole number. 

The scale of the instrument reads from — 5 to 105, corresponding 
to indices of refraction of from 1.32539 to 1.36640. It should be noted 
that the index of refraction may be read with a greater degree of accuracy 
on the immersion refractometer than on the Abbe instrument. 



THE REFRACT OMETER. 



-^3, 



Manipulation of the Immersion Refractometer. — Before using the 
instrument for the first time, it is necessar}- to see that the refractometer 
is correctly adjusted. For this purpose the bath A is placed with its 
long side parallel to the window and the mirror turned towards a bright 
sky, the bath is half filled v.ith tap-water, and a beaker filled with dis- 
tilled water is then placed in one of the five holes in the front row imme- 
diately above the mirror. Finally, the refractometer is hung bv its 
hook H upon the wire frame, the prism being totally submerged in the 
water contained in the beaker. 

The whole apparatus is now allowed to stand for ten minutes, or until 
the distilled water has acquired the exact temperature of the bath, and 
the ocular is focussed upon the di^•isions of the scale by turning the 
milled zone of the ocular shell until the lines and nimibers are seen quite 
distinctly, the mirror being adjusted so that the light of the bright 
sky is seen direcdy through the beaker. The upper part of the field 
from —5 to about 15 appears bright, and it is separated from the lower 
dark part by a sharp line of demarcation, if the index on the ring of 
the compensator stands at 5. 



SC-\LE READING AND INDEX OF REFR.\CTION OF DISTILLED WATER 
AT io-.:;o^ C, ACCORDING TO WAGNER. 



Teniper- i Scale 



29 
2S 



Index of "/) i^ifier- . Temper- • Scale 



Ature C I Reading. [Refraction, njy ence for 
1 ^°C. 



Index of 



Kn D-lrer- 



1-33196 
I-3320S 
1-332195 
1-332,1 



13 





I 


33242 


13 


25 


^ 


332525 


13 


^ 




332025 


13 


75 




33272 


14 







332SI 


14 


2; 




33290 


14 


:; 




33209 



"•5 

II. o 

10-5 
10. o 

9-5 
9.0 
9.0 



ature C. Reading. Refraction, n^) ' ence for 

'1 1° C. 



10 
iS 



16 
15 
14 
13 

12 
II 



14 


- 




333075 


14 


9 




33316 [ 


1 ^5 







33320 


15 


I 




33324 ! 


1 i^ 


3 




333315 


15 


^ 




3:^339 , 


15 


7 




33546 


15 


»5 




333525 


16 







33359 


16 


15 




33365 


It) 


3 




3337^3 ' 



7 ■:> 
7-5 
70 
6.5 
6.5 
6.0 



8.0 



The reading is taken and the temjjerature of the- distUled water 
noted. Reference to the above table will show if the refractometer 
is' correctly adjusted. Should the average of several careful readings 
at a given temperature de\-iate from that contained in the table, the 
following should be resorted to: 

Readjustment of the Scale. — The ocular end of the refractometer 
hanging on the wire frame is grasped from behind with the thumb and 
forefinger of the left hand, the micrometer drum set to 10, and the steel 



114 FOOD INSPECTION y^ND yiN^ LYSIS. 

spike, housed in the case of the apparatus, inserted into one of the holes 
of the nickeled cross-holed screw lying on the inner side of the microm- 
eter drum. The spike is then turned anti-clockwise, as seen from the 
rear, whereupon the nickeled milled nut, which governs the micrometer, 
becomes loosened. The temperature of the distilled water in the beaker 
is taken once more to see that it has remained constant, and then the 
table (page 113) is consulted to find the "adjusting number" properly 
belonging to the temperature indicated. By turning the spike, the border- 
line is brought exactly upon the integer scale division appertaining to 
the adjusting number, and the loose micrometer drum is turned so that 
the index accords with the decimal portion of the adjusting number. 
The drum is now held firmly with the thumb and forefinger of the left 
hand, while the nut is screwed up tight again by the right hand, taking 
care, however, that the drum does not wander off the index. Finally, 
the new adjustment is tested by repeated readings. 

Regulating the Temperature. — In many cases it suffices to allow water 
at the temperature of the room to flow slowly from a tank suspended 
high upon the wall through the bath. Should it be required, however, 
to maintain a given temperature (say 20° C.) for hours together con- 
stant to a tenth of a degree, which is frequently desirable if not actually 
necessary, a more elaborate temperature-regulating device should be 
employed. In cold weather, or when the tap-water has a lower tempera- 
ture than that desired, a refractometer heater of the type shown in 
Fig. 37, and described on page 102, is convenient. 

When, as in the summer, the tap-water temperature is higher than 
that desired for the refractometer bath, there are various ways of success- 
fully controlling the temperature at a lower degree. An ice-water tank 
placed above the level of the bath may be employed, the flow from 
which through the bath is carefully controlled by a pinch-cock or 
otherwise, or is allowed to mingle, under careful regulation before 
entering the bath, with the water from the tap direct or with that from 
the heater. 

Investigation of Solutions in Beakers in Bulk. — The first ten solutions 
are poured into beakers until two-thirds full, and the latter are immersed 
and brought to the temperature of the bath A. When the first five solu- 
tions have been measured, they are taken out of the water-bath and 
the second series of five beakers inserted in their place, bringing at the 
same time a third series into the water-bath. The second series are 
measured and so on. Small gummed labels on the outside prove quite 
satisfactory for numbering the beakers. It is absolutely necessary to 



THE REFRACTOMETER. 



115 



compare the temperature of the solutions in the beakers with the water- 
bath from time to time. 

After each immersion, the prism should be wiped dry with a clean, 
soft piece of old linen. 

Investigations of Solutions Excluded from Air. — Quickly evaporating 
liquids, for instance ether solutions, should be treated individually by 
means of the metal beaker adapted to fit the prism end of the refrac- 
tometer. To fill the beaker, the refractometer is held in the left hand 
with the prism pointing upwards, and the metal beaker {M, Fig. 40) 
is set and securely fastened by means of the bayonet joint. It is now 
filled quite full and the cover D carefully fitted and locked. 

The solution is now enclosed, air and water tight. The refractometer 
as before is hung upon the wire frame of the bath, with the metal beaker 
submerged in the bath. 

It is expedient to place the solutions before investigation in closed 
flasks in the nine unoccupied holes in the bath. 

After the measurement, the refractometer is held in the left hand 
with the prism pointing downwards, and the beaker together with its 
cover detached by giving a slight turn with the right hand. The solu- 
tion can be used for other purposes, since it has undergone no change 
in constitution. Finally, the cover is detached from the beaker, and 
cover, beaker, and prism cleaned by simple means, and the refractometer 
made ready for the reception of the next solution, as above. 

Investigations of Small Quantities of Solutions with the Auxiliary 
Prism. — When the solution does not occur in sufficiently large quan- 
tities for investigation in the glass beaker, or when the solution is too 
deeply colored, as in dark beers, molasses, etc., the auxiliary prism is 
used. As described under "Solutions Excluded from Air," the metal 
beaker without cover is fitted on the refractometer. The auxiliary prism 
is held horizontally, and, a few drops of the solution having been applied 
to the hypothenuse face, the prism is inserted into the metal beaker, 
held conveniently for the purpose, with its hypothenuse face laid upon 
the polished elliptical face of the refractometer prism, and then locked 
in by the cover. If an insufficient quantity of the solution has been 
taken, the margins of the out-spread drops lying between the two prisms 
can be recognized by looking through the window of the cover on which 
abuts the square polished end of the auxiliary prism. It is strongly 
recommended, wherever possible, to apply a sufficiency of the solution, 
so that the space between the prisms is completely filled, otherwise a loss 
in brilliancy occurs, and, under certain circumstances, an unavoidable 



ii6 



FOOD INSPECTION AND /IN 4 LYSIS. 



TABLE OF IxNDlCES OF REFRACTION, «^. 
(Compared with Scale Readings of Zeiss Immersion Refractometer, according to Wagner.) 



Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


«/>■ 


Read- 


"Z)- 


Read- 


n^. 


Read- 


n,j. 


Read- 


njj. 


ing. 




ing. 




ing. 




ing. 




ing. 




o.o 


r. 3 2 7360 


5-0 


1.329320 


10.0 


I .331260 


15.0 


1.333200 


20.0 


1-335168 


O. I 


1-327309 


5-1 


1-329350 


10. 1 


t -331299 


15-1 


I • 3332.38 


20.1 


I-335168 


2 


438 


2 


398 


2 


388 


2 


276 


2 


206 


3 


477 


3 


437 


3 


377 


3 


314 


3 


244 


4 


516 


4 


476 


4 


416 


4 


352 


4 


282 


5 


555 


5 


515 


5 


455 


^ 


390 


5 


320 


6 


594 


6 


554 


6 


494 


6 


428 


6 


358 


7 


(>3i 


7 


593 


7 


533 


7 


466 


7 


396 


8 


672 


8 


632 


8 


572 


8 


504 


8 


434 


9 


711 


9 


671 


9 


611 


9 


542 


9 


472 


I.O 


750 


6.0 


710 


II .0 


650 


16.0 


580 


21.0 


510 


I.I 


r. 327789 


6.1 


1.329749 


II . I 


1. 33 1 689 


16. 1 


I -333619 


21. 1 


1-335549 


2 


828 


2 


788 


2 


728 


2 


658 


2 


588 


3 


867 


3 


827 


3 


767 


3 


697 


3 


627 


4 


906 


4 


866 


4 


806 


4 


736 


4 


666 


5 


945 


5 


905 


5 


845 


5 


775 


5 


705 


6 


984 


6 


944 


6 


884 


6 


814 


6 


744 


7 


T. 328023 


7 


982 


7 


932 


7 


833 


7 


783 


8 


062 


8 


1.330022 


8 


962 


8 


892 


8 


822 


9 


lOI 


.9 


061 


, 9 


t .332001 


9 


931 


9 


861 


2,0 


140 


7.0 


100 


12.0 


040 


17.0 


970 


22.0 


900 


2.1 


I. 328180 


7-1 


1-330139 


12. 1 


1.332078 


17. 1 


I . 334008 


22. 1 


1-3359.18 


2 


220 


2 


178 


2 


116 


2 


046 


2 


976 


3 


657 


3 


217 i 


3 


154 


3 


084 


3 


I -336014 


4 


300 


4 


256 


4 


192 


4 


122 


4 


052 


5 


340 


=; 


295 


5 


230 


5 


160 


5 


090 


6 


380 


6 


334 


6 


2(58 


6 


198 


6 


128 


7 


420 


7 


373 


7 


304 


7 


236 


7 


166 


8 


460 


8 


412 


8 


344 


8 


274 


8 


204 


9 


500 


9 


451 


9 


382 


9 


312 


9 


242 


3-0 


540 


8.0 


490 


13.0 


420 


18. 


350 


23.0 


280 


3-1 


I. 3285 79 


8.1 


1-330528 


I3-I 


t- 332459 


18. 1 


I • 334389 


23.1 


I -336319 


2 


618 


2 


566 


2 


498 


2 


428 


2 


358 


3 


657 


3 


604 


3 


537 


3 


467 


3 


397 


4 


696 


4 


642 


4 


576 


4 


506 


4 


436 


s 


735 


5 


680 


5 


615 


5 


545 


5 


475 


6 


774 


6 


718 


6 


654 


6 


584 


6 


514 


7 


813 


7 


756 


7 


693 


7 


623 


7 


553 


8 


852 


8 


794 


8 


732 


8 


662 


8 


592 


9 


891 


9 


832 


9 


771 


9 


701 


9 


631 


4.0 


930 


9.0 


870 


14.0 


810 


19.0 


740 


24.0 


670 


4-1 


r . 328969 


9.1 


I ■ 330909 


14. 1 


1-332849 


19. 1 


1-334770 


24.1 


I . 336708 


2 


I . 329008 


2 


948 


2 


888 


2 


818 


2 


746 


3 


047 


3 


987 


3 


927 


3 


857 


3 


784 


4 


085 


4 


I. 331026 


4 


966 


4 


896 


4 


822 


5 


125 


5 


104 


5 


1-333005 


5 


935 


5 


860 


6 


164 


6 


104 


6 


044 


6 


974 


6 


898 


7 


203 


7 


143 


7 


083 


7 


1-335013 


7 


936 


8 


242 


8 


182 


8 


122 


8 


052 


8 


974 


9 


281 


9 


221 


9 


161 


9 


091 


9 


I. 337012 


S-o 


320 


10. 


260 


15-0 


200 


20.0 


130 


25.0 


050 



THE RBHRACTOMETBR. 



117 





TABLE OF INDICES OF 


REFRACTION, 


n^ — {Cont 


'nued). 




Scale 




Scale 




1 Scale 




Scale 




Scale 




Read- 


«Z)- 


Read- 


«/)• 


Read- 


n^. 


Read- 


tijj. 


Read- 


nD. 


ing. 




ing. 




ing. 




ing. 




ing. 




25.0 


I • 337050 


30.0 


I . 338960 


35-0 


1 . 340860 


40.0 


1-342750 


45-0 


1.344630 


25.1 


1.337088 


30.1 


T . 338998 


35-1 


t . 340898 


40. I 


1.342788 


45-1 


1.344667 


2 


126 


2 


1-339036 


2 


936 


2 


826 


2 


704 


3 


164 


3 


074 


3 


974 


3 


864 


3 


741 


4 


202 


4 


112 


4 


1.341012 


4 


902 


4 


778 


5 


240 


5 


150 


5 


050 


5 


940 


5 


818 


6 


278 


6 


188 


6 


088 


6 


978 


6 


852 


7 


316 


7 


226 


7 


126 


7 


I -343016 


7 


889 


8 


354 


8 


264 


8 


164 


8 


054 


8 


Q26 


9 


392 


9 


302 


9 


202 


9 


092 


9 


963 


26'. 


430 


31.0 


340 


36.0 


240 


41.0 


130 


46.0 


I.345COO 


26.1 


t- 337468 


3I-I 


1-339378 


36.1 


t. 341278 


41. 1 


t- 343167 


46.1 


1-345037 


2 


506 


2 


416 


2 


316 


2 


204 


2 


074 


3 


544 


3 


454 


3 


354 


3 


241 


3 


III 


4 


582 


4 


492 


4 


392 


4 


278 


4 


148 


5 


620 


5 


530 


5 


430 


5 


315 


5 


185 


6 


6=^8 


6 


=;68 


6 


468 


6 


352 


6 


222 


7 


696 


7 


606 


7 


506 


7 


389 


7 


259 


8 


734 


8 


644 


8 


544 


8 


426 


8 


296 


9 


772 


9 


682 


9 


582 


9 


463 


9 


2,2,2, 


27.0 


810 


32.0 


720 


37-0 


620 


42.0 


500 


47.0 


370 


27.1 


1-337849 


32.1 


1-339758 


37-1 


1-341657 


42.1 


1-343538 


47-1 


1.345408 


2 


888 


2 


796 


2 


694 


2 


576 


2 


446 


3 


927 


3 


834 


3 


731 


3 


614 


3 


484 


4 


966 


4 


872 


4 


768 


4 


652 


4 


522 


5 


I . 338005 


5 


910 


5 


80 c; 


5 


690 


5 


560 


6 


044 


6 


948 


6 


842 


6 


728 


6 


598 


7 


083 


7 


986 


7 


879 


7 


766 


7 


636 


8 


122 


8 


t. 340024 


8 


916 


8 


804 


8 


674 


9 


161 


9 


062 


9 


953 


9 


842 


9 


712 


28.0 


200 


33 -o 


100 


38.0 


990 


43-0 


880 


48.0 


750 


28.1 


1.338238 


33-1 


r. 340138 


38.1 


1.342028 


43-1 


T. 343918 


48.1 


1-345787 


2 


276 


2 


176 


2 


066 


2 


956 


2 


824 


3 


3U 


3 


214 


3 


104 


3 


994 


3 


861 


4 


352 


4 


252 


4 


142 


4 


1.344032 


4 


898 


5 


390 


5 


290 


5 


180 


5 


070 


5 


935 


6 


428 


6 


328 


6 


218 


6 


108 


6 


972 


7 


466 


7 


366 


7 


256 


7 


146 


7 


I . 346009 


8 


504 


8 


404 


8 


294 


8 


184 


8 


046 


9 


542 


9 


442 


9 


332 


9 


222 


9 


083 


29.0 


580 


34-0 


480 


39-0 


370 


44 -o 


260 


49-0 


120 


29.1 


I. 338618 


34-1 


1-3-10518 


39-1 


1.342408 


44.1 


t- 344297 


49-1 


1-346158 


2 


656 


2 


556 


2 


446 


2 


334 


2 


196 


3 


694 


3 


594 


3 


484 


3 


371 


3 


234 


4 


732 


4 


632 


4 


522 


4 


408 


4 


272 


5 


770 


5 


670 


5 


560 


5 


445 


5 


310 


6 


'<o8 


6 


708 


6 


^98 


6 


482 


6 


348 


7 


846 


7 


746 


7 


636 


7 


519 


7 


386 


8 


884 


8 


784 


8 


674 


8 


556 


8 


424 


9 


922 


9 


822 


9 


712 


9 


593 


9 


462 


30.0 


960 


35-0 


860 


40.0 


750 


45-0 


630 


50.0 


500 



ii8 



FOOD INSPECTION AND ANALYSIS. 





TABLE OF INDICES OF REFRACTION, 


n^ — (Conti 


nued). 




Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


njj. 


Read- 


n^. 


Read- 


«/>- 


Read- 


»£>■ 


Read- 


ttjj. 


ing. 




ing. 




ing. 




ing. 




ing. 




50.0 


1.346500 


55-0 


t. 348360 


60.0 


1. 350210 


65.0 


1.352050 


70.0 


1-353880 


50.1 


1-346537 


55-1 


1-348397 


60. 1 


1-350247 


65-1 


1.352087 


70.1 


1-353917 


2 


574 


2 


434 


2 


284 


2 


124 


2 


954 


3 


611 


3 


471 


3 


321 


3 


161 


3 


991 


4 


648 


4 


508 


4 


358 


4 


198 


4 


1.354028 


5 


685 


5 


545 


5 


395 


5 


235 


5 


065 


6 


722 


6 


582 


6 


432 


6 


272 


6 


102 


7 


759 


7 


619 


7 


469 


7 


309 


7 


139 


8 


796 


8 


656 


8 


506 


8 


346 


8 


176 


9 


833 


9 


693 


9 


543 


9 


383 


9 


213 


51-0 


870 


56.0 


730 


61.0 


580 


66.0 


420 


71.0 


250 


Si-i 


1.346907 


56.1 


1.348767 


61. 1 


I. 350617 


66.1 


1-352457 


71. 1 


1.354286 


2 


944 


2 


804 


2 


654 


2 


494 


2 


322 


3 


981 


3 


841 


3 


691 


3 


531 


3 


358 


4 


I. 347018 


4 


878 


4 


728 


4 


568 


4 


394 


5 


055 


5 


915 


5 


765 


S 


605 


5 


430 


6 


092 


6 


952 


6 


802 


6 


642 


6 


466 


7 


129 


7 


989 


7 


839 


7 


670 


7 


502 


8 


166 


8 


I . 349026 


8 


876 


8 


716 


8 


538 


9 


203 


9 


063 


9 


913 


9 


753 


9 


574 


52.0 


240 


57-0 


100 


62.0 


950 


67.0 


790 


72.0 


610 


52.1 


1.347277 


57-1 


1-349137 


62.1 


1-350987 


67.1 


1.352827 


72.1 


1.354646 


2 


314 


2 


174 


2 


I. 351024 


2 


864 


2 


682 


3 


351 


3 


211 


3 


061 


3 


901 


3 


718 


4 


388 


4 


248 


4 


098 


4 


938 


4 


754 


5 


425 


5 


285 


5 


135 


5 


975 


5 


790 


6 


462 


6 


312 


6 


172 


6 


1-353012 


6 


826 


7 


499 


7 


359 


7 


209 


7 


04Q 


7 


862 


8 


536 


8 


396 


8 


246 


8 


086 


8 


898 


9 


573 


9 


433 


9 


283 


9 


123 


9 


934 


53-0 


610 


58.0 


470 


63.0 


320 


68.0 


160 


73-0 


970 


53-1 


1-347647 


58.1 


1-349507 


63.1 


1-351357 


68.1 


1-353196 


73-1 


1-355006 


2 


684 


2 


544 


2 


394 


2 


232 


2 


042 


3 


721 


3 


581 


3 


431 


3 


268 


3 


078 


4 


758 


4 


618 


4 


468 


4 


304 


4 


114 


5 


795 


5 


655 


5 


505 


5 


340 


5 


150 


6 


832 


6 


692 


6 


542 


6 


376 


6 


186 


7 


869 


7 


729 


7 


579 


7 


412 


7 


222 


8 


906 


8 


766 


8 


616 


8 


448 


8 


258 


9 


943 


9 


803 


9 


653 


9 


484 


9 


294 


54-0 


980 


S9-0 


840 


64.0 


690 


69.0 


520 


74.0 


3Z° 


54-1 


I. 348018 


59-1 


1-349877 


64.1 


I. 351726 


69.1 


1-353556 


74-1 


1-355366 


2 


056 


2 


914 


2 


762 


2 


592 


2 


402 


3 


094 


3 


951 


3 


798 


3 


628 


3 


438 


4 


132 


4 


988 


4 


834 


4 


664 


4 


474 


5 


170 


5 


1-350025 


5 


870 


5 


700 


5 


510 


6 


208 


6 


062 


6 


906 


6 


736 


6 


546 


7 


246 


7 


099 


7 


942 


7 


772 


7 


582 


8 


284 


8 


136 


8 


978 


8 


808 


8 


618 


9 


322 


9 


173 


9 


I. 352014 


9 


844 


9 


659 


55° 


360 


60.0 


210 


65.0 


050 


70.0 


880 


75-0 


690 



THE REFRACTGMETER. 



119 





TABLE OF INDICES OF REFRACTION, 


« £, — ( Contin tied) . 




Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


^D- 


Read- 


«£>- 


Read- 


w^. 


Read- 


«/)• 


Read- 


M^. 


ing. 




ing. 




ing. 




ing. 




ing. 




75-0 


1-355690 


80.0 


1-357500 


85.0 


I - 359300 


90.0 


I .361090 


95 -0 


1.362870 


75-1 


1-355727 


80.1 


1-357536 


85-1 


1-359336 


90.1 


t . 361 1 26 


95-1 


1.362906 


2 


764 


2 


572 


2 


372 


2 


162 


2 


942 


3 


801 


3 


608 


3 


408 


3 


198 


3 


978 


4 


838 


4 


644 


4 


444 


4 


234 


4 


I. 3630 I 4 


5 


875 


5 


680 


5 


480 


5 


270 


5 


050 


6 


912 


6 


716 


6 


516 


6 


306 


6 


086 


7 


949 


7 


752 


7 


552 


7 


312 


7 


122 


8 


986 


8 


788 


8 


588 


8 


378 


8 


158 


9 


1-356023 


9 


824 


9 


624 


9 


414 


9 


194 


76.0 


060 


81.0 


860 


86.0 


660 


91 .0 


450 


96.0 


230 


76. 1 


1 . 356096 


81. 1 


1-357896 


86.1 


1 . 359696 


91. 1 


I .361486 


96.1 


1-363256 


2 


132 


2 


032 


2 


732 


2 


522 


2 


292 


3 


168 


3 


968 


3 


768 


3 


558 


3 


328 


4 


204 


4 


1.358004 


4 


804 


4 


594 


4 


364 


5 


240 


5 


040 


5 


840 


5 


630 


5 


400 


6 


276 


6 


076 


6 


876 


6 


666 


6 


436 


7 


312 


7 


112 


7 


912 


7 


702 


7 


472 


8 


348 


8 


148 


8 


948 


8 


738 


8 


518 


9 


384 


9 


184 


9 


984 


9 


774 


9 


554 


77.0 


420 


82.0 


220 


87.0 


I . 360020 


92.0 


810 


97-0 


590 


77-1 


1-356456 


82.1 


1.358256 


87.1 


1.360056 


92.1 


I 361846 


97-1 


1.363625 


2 


492 


2 


292 


2 


092 


2 


882 


2 


660 


3 


528 


3 


328 


3 


128 


3 


918 


3 


695 


4 


564 


4 


364 


4 


164 


4 


954 


4 


730 


5 


600 


5 


400 


5 


200 


5 


990 


5 


765 


6 


636 


6 


436 


6 


236 


6 


I. 362026 


6 


800 


7 


672 


7 


472 


7 


272 


7 


062 


7 


835 


8 


708 


8 


508 


8 


308 


8 


098 


8 


870 


9 


744 


9 


544 


9 


344 


9 


134 


9 


905 


78.0 


780 


83-0 


580 


88.0 


380 


93-0 


170 


98.0 


940 


78.1 


I. 356816 


83-1 


I. 358616 


88.1 


I. 36041 6 


93-1 


1.362205 


98.1 


I - 36397.5 


2 


852 


2 


652 


2 


452 


2 


240 


2 


I. 364010 


3 


888 


3 


688 


3 


488 


3 


275 


3 


045 


4 


924 


4 


724 


4 


524 


4 


310 


4 


080 


5 


960 


5 


760 


5 


560 


5 


345 


5 


"5 


6 


996 


6 


796 


6 


596 


6 


380 


6 


160 


7 


1-357032 


7 


832 


7 


632 


7 


415 


7 


195 


8 


068 


8 


868 


8 


668 


8 


450 


8 


230 


9 


104 


9 


904 


9 


704 


9 


485 


9 


265 


79.0 


140 


84.0 


940 


89.0 


740 


94 -o 


520 


99.0 


290 


79.1 


1-357176 


84.1 


1-358976 


89.1 


1-360775 


94-1 


I 362555 


99-1 


1-364325 


2 


212 


2 


I. 359012 


2 


810 


2 


590 


2 


360 


3 


248 


3 


048 


3 


845 


3 


625 


3 


395 


4 


284 


4 


084 


4 


880 


4 


660 


4 


430 


5 


320 


5 


120 


5 


915 


5 


695 


5 


465 


6 


356 


6 


156 


6 


950 


6 


730 


6 


500 


7 


392 


7 


192 


7 


98s 


7 


765 


7 


535 


8 


428 


8 


228 


8 


I. 361020 


8 


800 


8 


570 


9 


464 


9 


264 


9 


055 


9 


835 


9 


605 


80.0 


500 


85-0 


300 


90.0 


090 


95 


870 


100. 


640 



120 FOOD INSPECTION AND ANALYSIS. 

degradation of the sharpness of the bordcr-Hne. On the other hand, 
with a sufficient quantity of solution, the border-hne is surprisingly sharp. 

The refractometer is now suspended on the frame, and the measure- 
ment proceeded with as before described. After measurement, the cover 
is first removed, and the prism allowed to fall into the hollow of the 
hand, then the beaker is removed to enable the refractometer to be 
conveniently cleaned. 

Strengths of Various Solutions. — The most extensive work on the 
quantitative determination of the strength of a large number of common 
aqueous solutions with the immersion refractometer has been done by 
Wagner, who has published a large number of tables. These tables 
show the percentage strength (grams per loo cc. at 17.5° C.) of a large 
number of salt solutions and of acids, corresponding to the range of scale 
readings of the instrument, as well as of cane sugar, dextrose, formalde- 

SCALE READINGS ON IMMERSION REFRACTOMETER OF VARIOUS STAND- 
ARD REAGENTS USED IN VOLUMETRIC ANALYSIS.* 



Temperature C. 



15°. 16°. 17°. 17.5°. iS°. 19°. 20°. 21°. 22' 



Hydrochloric acid: 

Normal 

Tenth-normal 

Sulphuric acid: 

Normal 

Fifth-normal 

Tenth-normal 

Oxalic acid: 

Half-normal. ,. 

Tenth-normal 

Potassium bitartrate: 

Tenth-normal 

Potassium hydroxide: 

Normal 

Tenth-normal 

Sodium hydroxide: 

Tenth-normal 

Sodium thiosulphate; 

Tenth-normal 

Potassium bichromate: 

Tenth-normal 

Silver nitrate: 

Tenth-normal 

Sodium chloride: 

Tenth-normal 

Ammonium sulphocyanate : 

Tenth-normal 



37-45 
17.80 

30.60 

18.75 
17-15 

22.45 
17-15 

17-75 

43-90 
18.45 

18.50 
24.20 

17-75 
20.20 
18.20 
20.60 



37.20 
17.60 

30.40 
18.60 
16.95 

22.30 
16.95 

17-55 

43-65 
18.30 

18-35 
24.05 

17-55 
20.05 
18.00 
20.45 



36.8 
17-30 

30.1 

18.30 

16.65 

22.00 
16.65 

17-25 

•+3-25 
18.00 

18.05 
23-75 
17-25 
19-75 
17.70 
20.15 



36.70 
17.20 

29-95 
18.20 

16.55 

21.90 
16.55 

17-15 

43.10 
17.90 

17.05 
23-65 
17-15 
19.65 
17.60 
20.05 



36.45 
17.00 

29-75 
18.00 

16.35 

21 . 70 
16.35 

16.95 

42.80 
17.70 

17-75 
23-45 
16.95 

19-45 
17.40 
19.85 



2035 
8016 



50,29 
8017 

15I15 



21.50 



5042 
5017 



17 



9535-70 
55 16.30 



25 
55 
90 

25 
9o|i5-65 



29.00 
17.30 
15-65 



16.25 

41-95 
17.00 

17-05 
22.70 
16.25 

18.75 
16.70 

19-15 



* According to Wagner, all these solutions were made up at 17.5° C Readings at different tem« 
peratures are given for convenience. 



THE REFR^CTOMETER. 



121 



hyde, alcohol, etc. All these observations have been based on the Mohr 
liter, at a temperature of 17.5°. More convenient for the American 
analyst would be tables based on the use of a higher temperature, say 20°, 
and the analyst is recommended to work out his own standards for com- 
parison, at the temperature best suited to his special locality and conven- 
ience. The instrument is especially useful in preparing normal and tenth- 
normal solutions. 

The table on page 1 20, from Wagner, shows the strength of various 
common laboratory reagents. 



SCALE READINGS AT TEAIPERATURES FROM 10-30° C. 
Corrected to 17.5°, According to Wagner. 



No. 


i. 


2. 


'■ 


4- 


s. 


6. 


7- 


8. 


9. 


10. 


II. 


12 & 13. 


No. 


t'J 










Scale 


Reading at 


7.5° c 










t'J 




15. 


20. 


25- 


30. 


35. 


40. 


45. 


so- 


60. 


70. 


80. 


QO & 100. 


F2 

Z2 


30 


•^3.20 


3-15 


3-25 


3-40 


3-55 


3-65 


3-9° 


4-05 


4.20 


4.60 


4.80 


5-25 


3° 


29 
28 

27 
26 


2.90 
J. 60 
2. 30 
J. DO 


2.85 

2-55 
2.25 
1.95 


2-95 
2.65 

2-35 
2.05 


3.10 
2.80 
2.50 
2.20 


3-25 
2-95 
2.65 

2-35 


3-35 
3-05 
2-75 
2.45 


3-55 
3-25 
2-95 
2-55 


3-75 
3-45 
3-15 
2.80 


3-9° 
3.60 

3-3° 
2-95 


4.25 
3-90 

3-5° 
3.10 


4-45 
4. 10 

3-75 
3-30 


4.85 

4-5° 
4. 10 

365 


29 
28 
27 

26 


25 


i.75 


1-75 


1.80 


1.90 


2.05 


2.15 


2.25 


2.45 


2.60 


2.70 


2-95 


3.20 


25 


24 
23 
22 
21 


t 5° 
1 25 
1,00 
0-75 


1-45 
1.25 
1. 00 
0-75 


1-55 
1.30 
1.05 
0.80 


1.60 

1-35 
1. 10 
0.85 


1-75 
1-45 
I -15 
0.90 


1.85 

1-55 
1.25 

0-95 


1-95 
1.65 
1.30 
1.05 


2. 10 

1-75 
1.40 
1.05 


2.25 
1 .90 

1-55 
1.20 


2-35 
2.00 

1.65 

1-25 


2-55 
2-15 
1-75 
1-35 


2-75 
2-35 
1.90 

1-45 


24 
23 

22 
21 


20 


0.50 


0.50 


0-55 


0.60 


0.65 


0.65 


0.75 


0-75 


0.85 


0.90 


0-95 


1.05 


20 


19 
18 


0.30 
0.10 


0.30 

O.IO 


0.30 
0. 10 


0-35 
0.13 


0.40 
0.15 


0.4c 
0.15 


0.45 
015 


0.45 
0.15 


0.45 
015 


0-55 
0.20 


0-5S 
0.20 


0.60 
0.20 


19 
18 


17-5 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


17.5 


17 

16 


— 0. 10 
0.30 


0. 10 

0.30 


0. 10 
0.30 


O.IO 

0.30 


O.IO 

0-35 


0. 10 
0-35 


0.15 
0.40 


0.15 
0.45 


015 
0.45 


0.15 
0.50 


0.20 
0-55 


0.20 
0-55 


17 
16 


15 


0.50 


0.45 


0.45 


0.50 


0.60 


0.60 


0.65 


0-75 


0-75 


0.80 


0.85 


0.90 


15 


14 
13 
12 
II 


0.70 
0.85 
1. 00 
I-I5 


0.60 

0-75 


0.60 
0-75 


0.70 

0.85 


0.80 
1. 00 


0.85 
1. 10 


0.90 
I -15 


0.95 
1.20 


1.05 
1-35 


1. 10 
1.40 


1.25 
1-55 


1-25 
1.60 


13 
12 


i 


1 
















II 




' 


















10 


1-25 




1 


















1 


















No. 


I. 


2. 


3- 


4. 


s. 


6. 


7. 


8. 


9- 


10. 


II. 


--2 & 13. 


Xo. 



12 2 FOOD INSPECTfOS ASD ANALYSIS. 



REFERENCES OX THE BUT\'RO-REFRACTOMETER. 

Lythgoe, H. C. The Optical Projjerties of Castor Oil, Cod-liver Oil, Xeats-foot Oil, 

and a few Essential Oils. Jour. Am. Chem. Soc., 27, 1905, p. 887. 
Schneider, C, and BLrvcENTELD, S. Beitrag zur Kenntnis animalischer Fette. 

Chem. Zeit., 30, 1906, p. 53. 
Sprinkmeyer, H., and Wagner, H. Beitrage zur Kenntnis des Sesamoles. Zeits. 

Unters. Xahr. Genuss., 10, 1905, p- 347. 
Ulzer, F., and Sommer. F. Uber den Xachweis xmd die Bestinmiimg des Paraffins 

in Mischimgen mit Ceresin. Chem. Zeit., 30, iqc6. p. 142. 

REFEREXCES OX THE WOLLX'Y ^HLK FAT REFRACTOMETER. 

Baier, E. Untersuchungen iiber den Xachweis der Wasserung von Milch mit Hilfe 
des Refraktometers. Ber. d. Xahr. Unters. d. Landw. f. d. Pro\-inz Branden- 
burg, 1904, p. 14. 

Ueber die Zuverlassigkeit der MUchunteRuchimgen mit dem Milch-refraktometer 

von Zeiss-Wollny. Molk. Zeit., 15, 1905, p. 386. 

CoTHEREAU, A. Xachweis einer Milchwasserung mittels des Refraktometers. BuU. 
Sci. Phann., 7, 1905, p. 68. 

Henseval, M., and MtxuE, G. La Refractometrie du Lait. Rev. gen. du Lait, 
4, 1905, p. 529. 

REFEREXCES OX THE ABBE REFR-\CTOMETER. 

Har\'ey, T. F. Temperature Corrections for Use with the Abbe Refractometer, and 
Refractive Indices of some Fixed and Essential Oils. Jour. Soc. Chem. Ind.. 24. 
1905, p. 717. 

Lythgoe, H. C. The Optical Properties of Castor Oil, Cod-liver Oil, Xeats-foot Oil, 

and a Few Essential Oils. Jour. Am. Chem. Soc., 27, 1905, p. 887. 
Utz, Fr. Beitrage zur Untersuchimg von .Amylalkohol. .\llgemeine Chem. Zeit., 

6, 1906, p. 106. 
Die Untersuchimg von Spiritus mittels des Refraktometers. Pharm. Xach., 

I, 1906, p. 74. 

REFEREXCES OX THE ESFNIERSIOX REFR-\CTOMETER. 

AcKERMANN, E. Ueber refraktometrische Bieranalyse. Zeits. f. d. ges. Brauw., 28, 

1905, p. 441- 
Methode refrartometrique rapide d'analyse de la biere a I'aide d'un calcuJateur 

automatique. Ann. et Rev. de Chim. Anal., 1905, p. 171. 
AcKERM-ANN, E., et VON Spin'dlkr, O. Sur la Determination de I'Eitrait de la Bierre. 

Jour. Suisse de Chim. et Pharm., 1903. Xo. 30. 
Hants, J., and Chocensey, K. .\nwendung des Zeisschen Eintauchrefraktometers 

in der Xahnmgsmittelanalyse. Zeits. Unters. Xathr. Genuss., 11, 1906, p. 313. 



THE REFRACTOMETER. 123 

Leach, A. E., and Lythgoe, H. C. The Detection and Determination of Ethyl and 

Methyl Alcohols in Mixtures by the Immersion Refractometer. Jour. .\m. 

Chem. Soc, 27, 1905, p. 964. 
A Comparative Refractometer Scale for Use with Fats and Oils. Jour. Am. 

Chem. Soc, 26, 1904, p. 1193. 

The Detection of Watered Milk. Ibid., p. 1195. 

KiONK.\, H. Ueber naturliche und kunstliche Mineralwasser. Balneolog. Zeit., 14, 

Xos. 34 u. 35. 
^LANSFELD, M. Die \'erRendbarkeit des 2^iss'schen Eintauchrefractometer bei 

Xahrungsmittel-Untersuchung. Unters. .\nst. osters. Apoth.-\'ereins. Ber., 

1904-1905, p. 10. 
M.ATTHES, H. Quantitative Bestimmimgen wasseriger Losungen mit dem Zeiss'- 

schen Eintauch-Refraktometer. Zeits. Unters. Xahr. Genuss., 5, 1902, p. 1037. 
Ueber refraktometrische anahtische Bestimmungsmethoden. Zeits. anal. Chem., 

13, 1904, p. 73 . 
MoHR, M. Die Anwendtmg des Zeiss'schen Eintauchrefraktometers im Brauereilabo- 

ratorium. Wochens. Brau., 22, 1905, p. 616. 
MoHR, O. Refraktometrische Extraktbestimmimg bei der Malzanalyse. Wochens. f. 

Brau., 23, 1906, p. 136. 
W.\GNER, B. Xeue Methoden der quantitativen Bestimmung mit dem Zeiss' schen 

Eintauchrefraktometer. Zeits. oflfentl. Chem., 11, 1905, p. 404. 
Ueber quantitative Bestimmimgen wasseriger Losungen mit dem Zeiss' -schen 

Eintauch-Refraktometer. Sondershausen, 1903. 

Tabellen zum Eintauch-Refraktometer. Sondershausen, 1907. 

W.A^GNER, B., and Rinck, A. X'eue Methode der quantitativen Zuckerbestimmung 

mit dem Zeiss' schen Eintauchrefraktometer. Chem. Zeit., 30, 1906, p. 38. 
Zeits. Chem. Apparat, Berlin, i, 1906, p. 207. 



CHAPTER VII. 

MILK AND ITS PRODUCTS. 
MILK. 

Nature and Composition. — ^Slilk is the secretion of the mammary 
glands of female mammals for the nourishment of their young. Con- 
taining as it does all the requisites for a complete food, i.e., sugar, fat, 
proteins, and mineral ingredients, combined in appropriate proportion, 
there is ample reason why it occupies so high a place in the scale of human 
foods. It is a yellowish-white opaque fluid, denser than water, contain- 
ing in complete solution the sugar, soluble albumin, and mineral content, 
and, in less complete solution, the casein, while the fat-globules are held in 
suspension in the serum, forming an emulsion. 

The specific gravity of pure milk ranges from 1.027 to 1.035. 

Milk from various animals has the same general physical properties 
and the same ingredients, differing, however, in percentage composition. 
Of all the varieties, the milk of the cow is by far the most important from 
its universal use, and, unless otherwise qualified, the term milk wherever 
it occurs in this volume will be understood to mean cow's milk. 

Acidity. — When perfectly fresh, milk of carnivorous mammals is, 
as a rule, acid in reaction, while human milk and that of the herbivora is 
alkaline. Cow's milk, when freshly drawn, is more often amphoteric in 
reaction, i.e., it reacts acid with blue and alkaline with red litmus. It soon 
becomes distinctly acid, and the acidity increases as the milk sugar grad- 
ually becomes converted into lactic acid. 

Microscopical Appearance. — Under the microscope pure milk shows 
a conglomeration of various-sized fat globules having a pearly lustre, j 
These globules vary from o.ooi to o.oi mm. in diameter, averaging about 
0.005 ^^- When examined under very high powers, it is possible to 
distinguish bacteria in the milk, the number to be seen depending greatly 
on the time that has elapsed since the milk was drawn from its source, 

as well as on the surroundings, the conditions of handling, exposure, etc. 

124 



MILK. i2t 

Color, — The yellow color of milk is imparted to it by the fat globules, 
and varies greatly in milk from different breeds of cattle, as well as in 
milk from the same cow at different seasons, being, as a rule, paler during 
the winter or stall-fed months, and having its greatest intensity soon after 
the cow is put out to pasture. 

Milk Sugar, the carbohydrate of milk, is normally present in amounts 
varying from 3 to 5 per cent. For the properties of milk sugar see page 577. 

The Proteins of Milk. — Casein constitutes about 80*^7 of the entire 
proteins of milk, being present in an average sample to the extent of about 
3^. It exists in combination with calcium phosphate, and probably 
does not form a perfect solution in the milk, but is rather diffused therein 
in a somewhat colloidal form, being so finely divided, however, as to be 
incapable of separation by filtration while the milk is fresh. 

Pure casein is a white, odorless, and tasteless solid, sparingly soluble 
in water, and insoluble in ether and alcohol. It is readily soluble in dilute 
alkalies. Strong acids also dissolve it, but its character is changed. From 
alkaline solution it is precipitated without change by neutralizing with 
acid. Its solutions are laevo-rotar}'. 

Lad-albumin is the soluble albumin of milk, existing therein to the 
extent of about 0.6'^ and forming about 1^% or more of the milk proteins. 
It much resembles the albumin of eggs, being coagulated at 70° to 75° C. 
It is readily soluble in water. Its specific rotar\- power according to 
Bechamp is [a]D= "67.5. 

Lactoglobidin has been discovered by Emmerling as a constituent in 
milk, but exists in traces only. According to Babcock, it may be separated 
from milk whey by carefully neutraHzing with sodium hydroxide, and 
aftenvards saturating with magnesium sulphate. It much resembles the 
globuhn of blood serum, being coagulated at 67° to 76° C. 

Fibrin.— Bahcock has discovered in milk ver}' minute traces of a 
substance analogous to the fibrin of blood. This substance, it is claimed, 
forms a part of the sHme found in the separator-bowl of a centrifugal 
skimmer. 

Other Xitrogenous Substances.— Besides the above norm.al constituents 
of milk, certain bodies may be formed by proteohtic action during fer- 
mentation, such, for example, as caseoses and peptones, formed for the 
most part by the decomposition of a part of the casein. Galactin is a 
gelatin-Hke body of the natunt of peptone, occurring in traces in milk. 
Besides these, minute traces of amido-bodies, such as creatin and urea, 
are sometimes present, and also ammonia. 



126 



FOOD INSPECTION AND ANALYSIS. 



O „ =^ ^ 

S till 
O . ■ 

CM 

o 

U 

w 

w 

H 

O 
I— I 

o 



itin 

slin 


.S 
'n 



t- o u 






OPHCo<;mpQUOU 







MILK. 



127 



Milk Fat. — Fat forms the most variable constituent of milk, being 
found in proportions ranging from 2.5 to 7 per cent. For the chemical 
composition and characteristics of milk fats see Butter (p. 529). 

The fat globules are held in suspension in the milk and have long 
been thought to be surrounded each by a thin nitrogenous membrane, 
known as Starch's mucoid protein, which becomes broken on churning. 
This theor}', while rendered probable by many of the phenomena 
connected with the dair}', is by no means uni\'ersally held at present. 

Citric Acid has been found to exist in milk, probably in combina- 
tion with certain of the mineral constituents, being present to the extent 
of about 0.1%. 

The table on page 126 arranged by Babcock shows quite clearly the 
percentage composition of an average cow's milk. 

For comparison of milk from different animals the following table * 
is inserted, showing in most cases minimum, maximum, and mean deter- 
minations from a large number of actual analyses: 



,No. of 
Anal- 1 
yses. 



Specific 
Gravity. 



Water. 



Casein. 



Albu- 
min. 



Total 
Pro- 
teids. 



Fat. 



Milk 
Sugar. 



Ash. 



Cow's milk. . . 800 

Minimum 1.0264 

Maximum 1.0370 

Mean i .0315 

Human milk 200 

Minimum I 1.027 

Maximum I 1 1.032 

Mean I 

Goat's milk 200 

Minimum , 1.0280 

Maximum i .0360 

Mean i .0305 

Ewe's milk 32 

Minimum 1.0298 

Maximum 1 .0385 

Mean i .0341 

Mare's milk | 47 

Mean i -0347 

Ass's milk 5 

Mean I i .036 



So. 32 
90.32 
87.27 



74-47 
87.02 
80.82 



1-79 
6.29 
3.02 



81.09 0.18 

91.40 1.96 

87.41 1.03 

82.02 ! 2.44 

90.16 i 3.94 

85-71 1 3-20 



3-59 
5-69 
4-97 



90.78 1.24 0.75 
89.64 I 0.67 I 1.55 



0.25 

1-44 
0-53 


2.07 
6.40 

3-55 


0.32 
2.36 
1.26 


0.69 
4.70 
2.29 


0.78 




2.01 




1.09 


4.29 


0-83 
1-77 
1-55 


6.52 


0-75 


1-99 


1-55 


2.22 



1.67 

6.47 
3-64 

1-43 
6.83 

3-78 

3.10 

7-55 
4-78 

2.81 
9.80 
6.86 



1.64 



2. II 
6.12 

4.88 

3-88 
8-34 
6.21 

3.26 

5-77 
4.46 

2.76 

7-95 
4.91 

5-67 
5-99 



■35 
.21 



.90 
-31 

-39 
.06 
.76 



.89 
-35 



Composition of the Ash of Milk. — The ash of milk does not truly 
represent the mineral content, since, in the process of incineration, the 
character of some of the constituents is altered by oxidation and otherwise. 

Expressed in parts per loo, the ash of the typical milk sample whose 
full analysis is given on page 126 would be about as follows: 



* Compiled from Konig's Chemie der mens. Nahr. u. Genuss. 



128 FOOD INSPECTION AND ANALYSIS. 

Potassium oxide 25 .02 

Sodium " 10.01 

Calcium " 20.01 

Magnesium " 2 .42 

Iron " 0-13 

Sulphur trioxide 3 . 84 

Phosphoric pentoxide 24. 29 

Chlorine 14. 28 



100.00 



Soldner regards the following as more nearly representing the propor- 
tion in which the mineral salts exist in milk: 

Per Cent. 

Sodium chloride, XaCl 10.62 

Potassium chloride, KCl 9.16 

Mono-potassium phosphate, KHsPO^ 12.77 

Di-potassium phosphate, K2HPO^ 9.22 

Potassium citrate, K3(CgH507)2 5-47 

Di-magnesium phosphate, MgHPO^ 3.71 

Magnesium citrate, Mg3(CgH50^)2 4-05 

Di-calcium phosphate, CaHPO^ 7 .42 

Tri-calcium phosphate, Ca3(PO^)2 8.90 

Calcium citrate, Ca3(CgH507)2 23.55 

Lime, combined with proteins 5 - ^3 



100.00 



Fore Milk and Strippings. — Unless a portion drawn from the well- 
mixed or whole complete milking of an animal is taken for analysis, one 
does not get a fair representative sample of the milk, for it is a well-known 
fact that the first portion of milk drawn from the udder, termed the * * fore 
milk," is very low in fat, while the last portions or "strippings" con- 
tain a very high fat content, sometimes exceeding lo^'^^ fat. The following 
analyses show the difference between fore milk and strippings in two 
cases : 



(i) Fore milk. 

Strippings. 
(2) Fore milk. 

Strippings. 



Per Cent Per Cent 

Water. Solids. 



88.17 I 11.83 

80.82 19.18 

88.73 11-27 

80.37 19-63 



Per Cent 
Fat. 



1.32 

9-63 

1.07 

10.36 



MILK. 



129 



The per cent of albuminoids, sugar, and ash is nearly the same in 
both fore milk and strippings. 

Colostrum. — The milk given by cows and other mammals for two or 
three days after the birth of young is termed colostrum, and differs ma- 
terially in composition from normal milk. It is yellow in color, of an 
oily consistency, and has a pungent taste. It acts as a purge upon the 
young. Examined under the microscope, it is found to contain large 
circular cells larger than fat globules and somewhat similar to blood 
corpuscles. It is very high in albumin, which seems to be similar to 
blood albumin. The following analyses were made by Engling, showing 
the composition of colostrum from a cow eight years old: 



Time after Calving, 

Immediately 

After 10 hours 

" 24 " 

"48 " 



Specific 
Gravity. 


Fat. 


Casein. 


Albu- 
min. 


Sugar. 


Ash. 


1.068 


3-54 


2.65 


16.56 


3.00 


1. 18 


1.046 


4.66 


4.28 


9-32 


1.42 


1-55 


1.043 


4-75 


4-50 


6.25 


2.8s 


1.02 


1.042 


4.21 


3-25 


2.31 


3-46 


0.96 


1-035 


4.0S 


3-3?, 


1.03 


4.10 


0.82 



Total 
Solids. 



26.93 
21.23 

19-37 
14.19 

13-36 



The average of twenty-two analyses of colostrum from different cows 
by EngUng showed total solids 28.31, fat 3.37, casein 4.83, albumin 15.85, 
sugar 2.48, ash 1.78. 

Frozen Milk. — Since it is the water in milk that freezes, it follows 
that in partially frozen milk the unfrozen portion of the milk, or that 
part which remains still hquid, becomes concentrated by the process of 
freezing. This is borne out by the following figures of Richmond: * 

Frozen Portion, Unfrozen Portion, 
Per Cent. Per Cent. 

Water 96 . 23 85.62 

Fat 1.23 4.73 

Sugar 1 .42 4.95 

Proteins 91 3-9° 

Ash .21 .80 

Specific gravity i . 0090 i . 0345 

Fermentations of Milk. — These arc due to the action of bacteria 
of various kinds, the most common being the lactic fermentation. 

The Souring 0} Milk is caused by the action of a large number of 
species of acid-forming bacteria, chief among which is the Bacillus acidi 
lactici, which multiplies faster than other bacteria in raw milk under 

* .•\nalyst, XVIII. p. 53. 



I30 FOOD INSPECTION AND ANALYSIS. 

favorable conditions of temperature. Part of the milk sugar is acted 
on and transformed, first into dextrose and galactose, the latter sugar 
subsequently forming lactic acid, as follows: 

(i) C,3H,30„,H,0 = QH,30e+C,H,30, 

Lactose Dextrose Galactose 

(2) QH,A=2C3He03 

Galactose Lactic acid 

More and more acid is formed until the casein can no longer be held 
up, curdling ensues, and the casein is precipitated. Finally, after a 
certain degree of acidity is reached, the ferment is killed and the action 
stops. Other acids than lactic are also undoubtedly produced, since a 
small part of the acid in sour milk is found to be volatile. According 
to Conn * the volatile acids are acetic and formic. 

Abnormal Fermentation. — Through the agency of micro-organisms 
that may develop under certain conditions, various changes are produced 
in milk that to some extent alter its character. Thus hitter milk is some- 
times produced as the result of some organism as yet but little understood. 

Occasionally milk is found possessing a peculiarly thick and slimy 
consistency, whereby it may be drawn out in threads, by dipping a spoon 
into the milk and withdrawing it therefrom. This is termed ropy milk, 
and is more often met with in warm weather. It is undoubtedly produced 
as a result of bacterial action. 

Enzyme- jorming Bacteria are not uncommonly developed in milk, 
causing various proteolytic changes, whereby the casein is partially trans- 
formed into peptones, caseoses, etc. 

Chromogenic Bacteria are the agencies that produce peculiar pigments 
in milk. Thus red milk is due to Bacillus crythrogcnes; yellow milk to 
Bacillus xynxanthus; blue milk to Bacillus cyanagenes. The latter is 
quite common, appearing ordinarily in patches in the milk. 

CHEMICAL ANALYSIS OF MILK. 

Ordinarily, in ascertaining the nutritive value of milk, one determines 
its specific gravity, total solids, fat, protein, milk sugar, and ash. Occa- 
sionally it is thought desirable to make a distinction in the case cf jirotcin 
between the casein and the albumin. Rarely is it necessary to further 
subdivide the nitrogenous bodies in milk, unless in connection with a 
special study of the proteolytic changes which it undergoes. 

The total solids, fat, and ash are usually all determined directly, and, 
* U. S. Dept. of Agric, Off. of Exp. Stations, BuL 25, p. 21. 



MILK. 



I;l 



in the case of the milk sugar and the proteins, a determination of either 
one may be directly made (whichever is most convenient), the other being 
calculated by difference. 

When foreign ingredients or adulterants are present in milk, special 
methods are employed to detect them. 

Preparation of the Sample. — In procuring a sample for analysis, 
the greatest care is necessary to insure a homogeneous sample. By far 
the best method in every case, where possible, is to pour the milk back 
and forth from one vessel to another (i.e., pour from the original container 
into an empty vessel and back at least once). Where 
this is impossible from the size of the container or for 
any other reason, the milk should be thoroughly mixed 
with a dipper. A " sampler," of which the Scovell samp- 
ling-tube (Fig. 41) is a convenient form, also aids in 
securing a representative sample, and is invaluable when 
it is desirable to secure a definite fraction of the whole 
for a composite sample. 

This instrument consists of a brass or copper tube 
made in two parts which telescope accurately together as 
shown in Fig. 41, the lower part being closed at the 
bottom, but provi'ded with three or more lateral slits. 
The sampler, drawn out to its full length, is carefully 
inserted in the tank containing the milk and lowered 
to the bottom, after which the upper part is pressed 
down over the lower so as to close the slits, and the 
tube is then lifted out of the tank, containing a fairly 
representative sample of the milk. 

In all operations to which a milk sample is submitted 
during the process of analysis, it should invariably be 
poured into a clean empty vessel and back, whenever it 
has been at rest for an appreciable time, in order to 
insure a homogeneous mixture. 

Determination of Specific Gravity. — This is most 
readily obtained with the aid of a hydrometer, accurately 

Fic JT Fir' J. 2 

graduated within the limits of the widest possible varia- 
tion in the specific gravity of milk. Hydrometers* for ypn Milk-sampling 
special use with milk are known as lactometers, and are Tube. 
graduated variously. One of the most convenient forms ^'^- 42.— The Que- 

.... . 1 /"v 1 11 venne Lactometer. 

of this instrument is the Quevenne lactometer, graduated 

from 15° to 40°, corresponding to specific gravity 1.015 to 1.040. This 



132 



FOOD INSPECTION AND /ANALYSIS. 



instrument, shown in Fig. 42, has a thermometer combined with it, the 
stem containing a double scale, on the lower part of which the specific 
gravity is read, while the temperature is read from the upper part. 

Another form of instrument is termed the New York Board of Health 
lactometer, which is not graduated to read the specific gravity directly, but 
has an arbitrary scale divided into 120 equal parts, the zero being equal 
to the specific gravity of water, while 100 corresponds to a specific gravity 
of 1.029. To convert readings on the New York Board of Health scale 
to Quevenne degrees they must be multiplied by .29. 



QUEVENNE LACTOMETER DEGREES CORRESPONDING TO NEW YORK 
BOARD OF HEALTH LACTOMETER DEGREES. 



Board of 
Health 
Degrees. 


Quevenne 
Scale. 


Board of 
Health 
Degrees. 


Quevenne 
Scale. 


Board of 
Health 
Degrees. 


Quevenne 
Scale. 


60 


17.4 


81 


23-5 


lOI 


29-3 


61 


17.7 


82 


23-8 


102 


29.6 


62 


iS.o 


83 


24.1 


103 


29.9 


63 


18.3 


84 


24-4 


104 


30.2 


64 


18.6 


8^ 


24.6 


105 


30-5 


65 


18.8 


86 


24.9 


106 


30-7 


66 


19. 1 


87 


25.2 


107 


31-0 


67 


19-4 


88 


25-5 


108 


3^-3 


68 


iQ-7 


89 


25.8 


109 


31.6 


69 


20.0 


90 


26.1 


IIO 


31-9 


70 


20.3 


91 


26.4 


III 


32.2 


71 


20.6 


92 


26.7 


112 


32-5 


72 


20.9 


93 


27.0 


113 


32-8 


73 


21.2 


94 


27-3 


114 


33--i 


74 


21-5 


95 


27.6 


115 


33-4 


75 


21.7 


96 


27.8 


116 


33-6 


76 


22.0 


97 


28.1 


117 


33-9 


77 


22.3 


98 


28.4 


118 


34.2 


78 


22.6 


99 


28.7 


119 


34.5 


79 


22.9 


100 


29.0 


120 


34.8 


So 


23.2 











If extreme accuracy is desired, the Westphal balance or the pycnometer 
should be used for the determination of specific gravity. For ordinar}' 
cases, however, the lactometer, if carefully made, is sufficiently accurate. 

With any other form of lactometer than the Quevenne, a separate 
thermometer is necessary in order to determine the temperature, the 
common practice being to standardize all such instruments at 60° F. 
(15.6° C). 

Readings at temperatures other than 60° may be corrected to that 
temperature by the aid of the table on page 133. 

Determination of Total Solids. — Dish Method. — For purposes 
of milk analysis, platinum dishes are by far the most desirable. These, 
if made for the purpose, should be of the shape shown in Fig. 52, mcasur- 



MILK. 



133 



FOR CORRECTING THE SPECIFIC GRAVITY OF MILK ACCORDING TO 
TEMPERATURE (BY DR. PAUL VIETH). 



Degrees Degrees of Thermometer (Fahrenheit). 

of 


L 


actom- 




























1 




eter. 45 


46 


47 


48 


49 


50 


51 


52 


Si 


54 


55 


s6 


57 


58 


59 ' 60 


20 


19.0 


19.0 


19. 1 


19. 1 19.2 


19.2 19.3 


19.4 


19.4 


19-5 


19.6I19.7 


19.8 


19.9 19.9 — 


21 


,19-9 


20.0 


20.0 


20.1 20.2 


20.2 20.3 


20.3 


20.4 


20.5 20.6 20.7 


20.8'20.9'20.9 


22 


20.9 


21.0 


21.0 


21. I 


21.2 


2I.2|2I.3 


21-3 


21.4 


21-5 


21.6I21.7 


21.8 


21.9 


21. 9I — 


23 


21.9 


22.0 


22.0 


22.1 


22.2 


22.2 22.3 


22.3 


22.4 


22-5 


22.6 22.7 


22.8 


22.8 


22.9! — 


24 


22.9 


22.9 


23.0 


23.1 


23-2 


23-2123-3 


23-3 


23-4 


23-5 


23.6J23.6 


23-7 


23-8 


23-9 — 


25 


23.8 


23-9 


24.0 


24.0 


24.1 


24.1,24.2 


24-3 


24.4 


24-5 


24.6 24.6 


24-7 


24.8 


24.91 — 


26 


24.8;24.9 


24-9 


25.0 


25-1 


25-1 25-2 


25.2 


25-3 


25-4 


25-5 25-6 


2=;-7 


25-8 


25-9i — 


27 


25.8125.9 


25.9 26.0|26.I 


26.1 26.2 


26.2 


26.3 


26.4 


26.5 


26.6 


26.7 


26.8 


26. 9I — 


28 


26.7 


26.8 


26.8 


26.9127.0 


27.0 27.1 


27.2 


27-3 


27.4 


27-5 


27.6 


27-7 


27.8 


27-Q 




2q 


'27.7 


27.8 


27.8 


27.9I28.O 


28.028.1 


28.2 


28.3 


28.4 


28. s 


28.6128.7 


28.8 


28. Q 


— 


30 


28.6 


28.7 


28.7 


28.828.9 


29.029.1 


29.1 


29.2 


29-3 


29.429.6 


29.7 


29.8 


29.9 


— 


31 


29.5 


29.6 29.6 


29.729.8 


29.930.030.1 


30.2 


30-3 


30-430-5 


30.6 


30.8 


30-9 


— 


32 


30-4 


30-5;30-5 


30.630.7 


3O-9I3I-O 


3I-I 


31-2 


3^-2, 


31-431-5 


31-6 


31-7 


31-9 


— 


z:^ 


i^-2, 


3I-43I-4 


31-531-6 


3I-8J3I-9 


32.0 


32-1 


32-3 


32-4132-5 


32.6 


32.7 


32-9 


— 


34 


32-2 


32-3,32-3 


34-432-5 


32-732-9 


33-0 


33-1 


33-2 


?>3-i:Z3-S iz-(> 


33-7 


33-9 


— 


35 


33-0 


3Z--i^3i-2 


33-4 33-5 


33-633.8 


33-9 


34-0 


34-234.334-534.6 


34-7 


34.9 


~ 





6t 


62 


63 


64 


6s 66 


67 


1 
68 1 69 


70 71 


72 


73 74 75 


20 


20.1 20.2 


20.2 


20.3 


20.4 20.5 


20.6 


20.720.9 


21.0 21. I 


21.2 


2I.3I2I.5 21.6 


21. 






21.1,21.2 


21.3 


21.4 


21.521.6J21.7 


2I.8;22.0 


22.1 22.2 


22.3 


22.4 


22.5 22.6 


22. 






22.1 22.2 


22.3 


22.4 


22.5 22.6 


22.7 


22.8 


23.0 


23.1 23.2 


23.3 


23.4 


23-5:23-7 


23- 






23.1,23-2 


22,-2, 


23.4 


23-523.6 


23.7 


23.8 


24.0 


24.1 24.2 


24.3 


24.4 


24.624.7 


24. 






24.1 24.2 


24.3 


24-4 


24.5 24.6 


24-7 


24.9 


25.0 


25.1125.2 


25.3 


25-5 


25.625.7 


25- 






25-1,25.2 


25.325.425.5 25.6 


25.7 


25.9 


26.0 26.1 26.2 


26.4 


26.5 


26.6,26.8 


26. 






26.1 26.2 


26. 3126. 5126. 6 26.7 


26.8 


27.0 


27.127.227.3 


27.4 


27.5 


27-7 


27.8 


27- 






27.1 


27-3 


27-427.5 27.627.7 


27.8 


28.0 


28.1 28.2I28.3 


28.4 


28.6 


28.7 


28.9 


28. 







28.1 


28.3 28.4 28. 5I28. 6 28.7 


28.8I29.0 


29.1 29.2J29.4 


29.5 


29-7 


29.8 


29.9 


29. 






29.1 29.3 29.4,29.5 29.629.8 


29.9,30.1 


30.230.3 


30.4 


30.5 


30.7 


30-9 


31.0 


30. 






30.1 


30. 330. 4130. 5 30.7,30-8 


3o.9'3i.i 


31. 231-3 


31.5 


31.6 


31.8 31-9 


32.1 


31. 






31-2 


31.331-4:31-5 31-731.7 


31.832.0 


32.232.4 


32.5 


32.6 


32.833-0 


33- r 


32. 






32.2 


32.3132.5132.632.732.9 


33.033-2 


33.333.4 


33.6 


33.7 


33.934.0 


34-2 


ii- 






33-2 


33.3 33.5I33-6 33.8 33-9 34-o 34-2 


34.334.5 


34.6 


34.7 


34.9'35-i 35.2 


34. 






34.2 


34.3 34.5,34.6 34.8 34.9 35.0 35.2 35.3 35.5 


35.6 


35.8 


36.0 


36.1 36.3 


35- 






35-2 


35.3 35.5 35.6,35.8 35.9 36.i'36.2 36.4^36.5 


36.7 


36.8 


37.0 


37.237.3 



ing about 2 J inches in diameter at the top, and 2\ inches in diameter 
at the bottom, having carefully rounded rather than square edges, and 
being h inch deep. The bottom is not perfectly flat, but slightly crowned 
outward. Such a dish will hold about 35 cc. 

For purposes of economy it is best to have these dishes spun out with 
a thick bottom, but with thin sides, not so thin, however, as to be too 
readily bent. 

If platinum dishes cannot be afforded, dishes of porcelain, glass, 
aluminum, nickel, or even tin may be used, but in all cases should be 
as thin as practicable. 

About 5 cc. of the thoroughly mixed sample of milk are carefully 
transferred by means of a pipette to a tared dish on the scale-pan, and its 



134 FOOD INSPECTION AND ANALYSIS. 

weight accurately determined. The dish with its contents is then trans- 
ferred to a water-bath, being placed over an opening preferably but little 
smaller than the diameter of the bottom of the dish, so that as large a 
surface as possible is in contact with the live steam of the bath. Here 
it is kept for at least two hours, after which the dish is wiped dry while 
still hot, transferred to a desiccator, cooled, and weighed.* 

Babcock Asbestos Method. t — Provide a hollow cyhnder of perforated 
sheet metal, 60 mm. long and 20 mm. in diameter, closed 5 mm. from 
one end by a disk of the same material. The perforations should be 
about 0.7 mm. in diameter and about 0.7 mm. apart. Fill loosely with 
from 1.5 to 2.5 grams of freshly ignited, woolly asbestos, free from fine 
and brittle material, cool in a desiccator, and weigh. Introduce a 
weighed quantity of milk (between 3 and 5 grams), and dry in a water- 
oven to constant weight, which is usually reached after four hours' heating. 

DETERMINATION OF ASH.— The platinum dish containing the milk 
residue, obtained in the determination of total solids by the dish method 
described above, is next placed upon a suitable support above a Bunsen 
flame (a platinum triangle or a ring stand is convenient for this), and 
the residue is ignited at a dull-red heat to a perfectly white ash, after 
which it is cooled and weighed. 

DETERMINATION OF FAT.— The Adams Method.— Without doubt 
the most accurate method of fat determination is by extraction with 
ether. For this purpose a strip of fat-free filter-paper about 2^ inches 
wide and 22 inches long is rolled into a coil and held in place by a wire 
as shown in Fig. 43. 

Schleicher and SchuU furnish fat-free strips especially for this work, but it 
is very easy to prepare the strips and extract them with theSoxhlet apparatus. 

About 5 grams of milk are run into a beaker with a pipette, and the 
weight of the beaker and milk are determined. The coil is then intro- 
duced into the beaker, holding it by the wire in such a manner that as 

* It is a common practice to transfer the milk residue, after a preliminary' drying on the 
water-bath, to an air-oven, kept at a temperature of from ioo° to 105°, where it is dried to 
a constant weight; but after an experience in analyzing over 30,000 samples of milk, the 
author is prepared to state that in his opinion the results obtained by the above method of 
procedure, using the water-bath alone, are more satisfactory'. It is impossible to keep a 
milk residue at a temperature above 100° for any length of time without its undergoing 
decomposition, especially as to its sugar content, as is shown by the darkening in color. A 
milk residue should be nearly pure white, a brownish color showing incipient decomposi- 
tion. Hence, by continued heating, especially at the temperature of 105°, the residue would 
continue to lose weight almost indefinitely. If it is thought best to give a final drying in 
the air-oven, the time should be short and the temperature employed should not in any case 
exceed 100°. 

t A. O. A. C. method, U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 117. 



MILK. 



135 




much as possible of the milk is absorbed by the paper. It is often possible 
to take up almost the last drop of the milk. By then weighing the beaker, 
the amount of milk absorbed by the coil is determined by difference, and 
the paper coil is hung up and dried, first in the air and then in the oven, 
at a temperature not exceeding 100°. Another method of charging 
the paper coil consists in suspending it by the wire and gradually deliver- 
ing upon it 5 cc. of the milk from a pipette, the densit}- of f^ 
the milk being known. 

The coil containing the dried residue is then transferred 
to the Soxhlet extraction apparatus (see p. 63 ) and sub- 
jected to continuous extraction with anhydrous ether for at 
least two hours, the recei^•ing- flask being first accurately 
weighed. The tared flask with its contents is freed from, 
all remaining ether, first on the water-bath and finally in 
the air-oven. It is then cooled and weighed, the increase 
in weight representing the fat in the amount of milk ab- 
sorbed by the coil. If there is any doubt about all the 
fat having been extracted at first, the process of extraction 
may be continued till there is no longer a gain in weight 
of the flask. Experience soon shows the length of time 
necessar}' for the complete extraction, which of course 
depends on the degree of heat employed, and the fre- 
quency with which the extracting-tube overflows. Two hours is ample 
for most cases, in which the conditions are such that the ether siphons 
over from the extraction-tube ten times per hour. 

Babcock Asbestos Method.* — Extract the residue from the deter- 
mination of water by the Babcock asbestos method with anhydrous ether 
in a continuous extraction apparatus, until aU the fat is removed, which 
usually requires two hours. Evaporate the ether, dry the fat in the extrac- 
tion flask at the temperature of boiling water, and weigh. The fat may 
also be determined by difference, dr>-ing the extracted cylinders at the 
temperature of boiling water. 

Fat Methods Based on Centrifugal Separation. — These 
methods are the most practicable for commercial work and for use by 
the public analyst, since they are much more rapid, and, if carefully 
carried out, practicaUy as accurate as the Adams method. They all 
depend upon the use of a centrifugal machine, having hinged pockets 
in which are carried graduated bottles, into each of which a measured 
quantity of milk is introduced. The milk is then subjected to the action 
of a suitable reagent, which dissolves the casein and liberates the fat in 

* A. O. A. C. method, U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 119. 



FiG. 43. — The 
Adams Milk- 
fat Coil. 



136 



FOOD INSPECTION AND ANALYSIS. 



a pure state, after which, by whirling at a high speed, the pockets are 
thrown out horizontally and the milk fat driven into the neck of each 
bottle, where the amount is directly read. 

Various processes of this kind, each having its own special adherents 
are in extensive use, among which the best known are the Babcock, the 
Leffman and Beam, the Gerber, and the Stokes. 

A resume of these processes, showing the reagents employed and other 
comparative data, is thus tabulated by Allen.* 



Milk 

Sulphuric acid, volume 

" " specific gravity 

Hydrochloric acid 

Amyl alcohol 



Babcock. 



17.5 cc. 

17.5 cc. 

1. 831 to 1.834 

None 

None 



Leffman- I 
Beam. ' 



Gerber. 



Stokes. 



15 cc. 
9 cc. 

1.85 

1.5 cc. 
1.5 cc. 



II cc. 15 cc. 

10 cc. j 13^ cc. 

.82 to 1.825! 1.82 to 1.83 

None ! None 

i.o cc. I 1-5 cc. 



The Babcock Process, devised originally for the use of creameries 
and dairymen, is now extensively employed for fat determination in 
the laboratory. 

It has stood the test of over ten years' successful use in the writer's 
hands. During this time on various occasions results as determined 
have been compared with those obtained by the Adams process, and the 
agreement has been as close as could be expected. The following figures 
show the results of such comparative determinations made in duplicate 
on three samples of milk, viz., a whole pure milk, (i) and (2); a watered 
milk, (3) and (4), and a milk centrifugally skimmed, (5) and (6). 

COMPARATIVE FAT DETERMINATION BY ADAMS-SOXHLET AND BY 
BABCOCK PROCESSES. 





Per Cent of 

Fat by the 

Adams-Soxh- 

let Process. 


Per Cent of 

Fat by the 

Babcock 

Process. 


A whole milk (i) 


4.27 
4.28 
2.70 

2-74 
0.16 
0.14 


4-30 
4-35 
2.70 
2.80 
CIS 
0.15 


(2) 


A watered milk (3) 


(4) 


A skimmed milk ("5) 


(6) 





The Centrifuge. — Various styles of centrifuge are in use for this process, 
some driven by hand, some by steam-power, and some by the electric 
motor, carrying from 4 to 40 bottles. Fig. 44 shows an 8-bottle hand 
machine, driven by friction gearing, as well as the steam-driven centrifuge 
in common use in dairies and creameries, which is a 20-bottle machine 

* Commercial Organic Analysis, IV. p. 150. 



MILK. 



13: 




Fig. 44. — Types of the Babcock Centrifuge and Appurtenances. Hand machine at the 
left; steam-driven machine at the right. 




Fig. 45- —Electrically-driven Babcock Centrifuge, with Aluminum Frame, Carrying 16 

Bottles. Acid burette at the left. 

A sheet-metal safety-shield (removed for showing the constructionj normally surrounds the 

instrument. Such a shield is shown in Fig. 11. 



138 



FOOD INSPECTION AND ANALYSIS. 



having paddles on the outer periphery of the revolving frame, against 
which the steam impinges, driving it like a horizontal water-wheel. 

The most noiseless and easy-running machine is that driven by an 
electric motor. An example of this kind of centrifuge is shown in Fig. 
45, carrying 16 bottles. 

The ordinary Babcock test bottle is shown in Fig. 46, A, that used for 
skimmed milk in Fig. 46, B. The bottles are graduated with reference 
to using 18 grams of the sample. 

Manipiilat'.on. — By means of a pipette graduated to hold 17.6 cc. 
(the average volume of 18 grams) that amount of the thoroughly mixed 
sample of milk to be tested is transferred to a test bottle, and 17.5 cc. of 
commercial sulphuric acid of a specific gravity of 1.82 to 1.84 are added 



a 



Fig. 46.— Babcock Test Bottles. A, Milk Bottle. B, Skimmed Milk Bottle. 

by means* of a graduate or an automatic burette, .shown in Fig, 44. The 
contents are then thoroughly mixed, (;luring which operation much heat is 
developed by the action of the acid on the proteins and milk sugar, and the 
mixture turns a very dark brown. The test bottles are then placed in the 
centrifuge pockets (an even number being always used, arranged opposite 
each other to properly balance) and whirled for at least five minutes. 
Hot water is then added up to the necks of the bottles, which are then again 
whirled for about two minutes. Enough hot water is then added to drive 
the fat into the neck of each bottle, and a final whirl of about a minute's 
duration is given, after which the bottles are removed from the pockets, 
and the percentage of fat is read, while still hot, from the graduated neck 
bv mcr.ns cf a pair of calipers. 



MILK. 



139 



The Wemer-Sclmiidt Method. — Ten cc. of milk are introduced by 
means of a pipette into a large test-tube of 50 cc. capacity, and 10 cc. of 
concentrated hydrochloric acid are added. The mixture is shaken and 
heated till the liquid turns a dark browTi, either by direct boiling for a 
minute or two, or by immersing the tube in boiling water for from five to 
ten minutes. The tube is then cooled by im- 
mersion in cold water, and 30 cc. of washed ether 
is added. The tube is closed by a cork provided 
with tubes similar to a wash-bottle, the larger 
tube being adapted to slide up and down in the 
cork, and preferably being turned up slightly at 
the bottom. The contents of the tube are 
shaken, the ether layer allowed to separate, and 
the sliding-tube arranged so that it terminates 
slightly above the junction of the two layers. 
The ether is then blown out into a weighed 
flask. A second and a third portion of ether 
of 10 cc. each are successively shaken vaxh. the 
acid Hquid and added to the contents of the 
weighed flask, from which the ether is subse- 
quently evaporated and the weight of the fat 
easily obtained. 

Instead of measuring the milk into the testing- 
lube, a known weight of milk may be operated on. A sour milk may be 
readily tested in this way. pro\-ided it is previouslv well mixed. 

Determination of Fat by the Wollny Milk-fat Refractometer.* — This 
instrument presents the same appearance as the butj'ro-refractometer, 
Fig. 36, with an arbitrar}- scale reading from o to ico, the equivalent 
readings in indices of refraction of ihe Wollny instnmient var\-ing from 
i.2>Z^2 to 1.4220. Exactly 30 cc. of the milk to be tested are measured 
into the stoppered flask .4, Fig. 48. This may be done by the use of 
the automatic pipette, which holds exactly 7^ cc, remoAing four pipettes 
full of the milk. .B is a numbered tin sampUng-tube in which the milk 
sample is kept for convenience, and into which the automatic pipette 
readily fits. Ha%ing measured 30 cc. of the milk into the flask A, 12 
drops of a solution of 70 grams potassium bichromate and 312.5 cc. of 
stronger ammonia in one Hter of water may be added as a presen-ative, 




Fig. 47- — ^The Werner-Schmidt 
Fat Apparatus. 



* Milch Zeit... 1900, pp. 50-53. 



I40 



FOOD INSPECTION yiND /iN/i LYSIS. 



if the sample is to be kept for some time before finishing the test. Twelve 
drops of glacial acetic acid are added to curdle the milk. The flask is 
then corked and shaken for one to two minutes in a mechanical shaker, 
after which 3 cc. of a standard alkaline solution are added, and the flask 
corked and shaken for ten minutes in the mechanical shaker, the tempera- 
ture being kept at 17.5° C. The standard alkahne solution is prepared 




Fig. 48. — Accessories for Carrying Out the Wollny !Milk-fat Process. 

by dissolving 800 cc. of potassium hydroxide in a liter of water, adding 
600 cc. of glycerin and 200 grams pulverized copper hydrate, the mixture 
being allowed to stand for several days before using, shaking at intervals. 
Finally 6 cc. of water-saturated ether are added to the mixture in the 
flask, using for convenience the automatic pipette fitted in the corked 
bottle as shown. The flask is again shaken for fifteen minutes in the 
mechanical shaker, and whirled for three minutes in the centrifuge, after 
which a few drops of the ether solution are transferred to the refractometer, 
and the reading taken. The percentage of fat is obtained by means of 
the following table: 



MILK 



141 



PERCENTAGES OF FAT CORRESPONDIXG TO SCALE READINGS ON THE 
WOLLXY REFRACTOMETER. 



Scale ' Per 

Reafl- Cent 

ing. Fat. 



0.00 
o.oi 
0.02 
0.03 
0.04 

0.05 

0.06 

0.08 

0.09 

O.IO 
O.II 

0.12 

8 I 0.13 

9 0-14 
22.0 0.15 



I 


0.16 


6 


2 

3 


0.17 
0.18 


7 
8 


4 


0.19 


9 


5 


0.20 


27.0 


6 


0.21 


I 


7 


0.22 


2 


8 


0.23 


3 


9 


0.24 


4 


23.0 


0.25 


5 


I 


0.26 


6 


2 


0.27 
0.28 


7 
8 


4 
5 


0.29 
0.30 


9 
28.0 


6 


0.31 


I 


7 


0.32 


2 


8 


0-33 


3 


9 
24.0 


0.34 
0.36 


4 
5 


I 
2 


0-37 
0.38 


6 

7 


3 


0-39 


8 


4 


0.40 


9 


5 


0.41 


29.0 

1 



Scale 
Read- 
ing. 



24-5 

6 

7 



3 
4 

5 

6 

7 
8 

9 
26.0 



Per I Scale 
Cent Read- 
Fat. I ing. 



0.41 

0.42 

0.43 
0.44 

0-45 
0.46 

0.47 
0.48 
0.49 
0.50 

°-5i 



0-53 
0.54 
0-55 
0-57 

0.58 

0-59 
0.60 
0.61 
0.62 

0.63 
0.64 
0.65 
0.66 
0.67 

0.68 
0.69 
0.70 
0.71 
0.72 

0-73 
0.74 

0-75 
0.76 
0.77 

0.78 
0.79 
0.80 
0.81 
0.82 

0.83 
0.84 
0.85 
0.86 

0.87 



Per 
Cent 
Fat. 



29.0 



7 
8 

9 
30.0 



3 
4 

5 

6 

7 
8 

9 
31.0 



7 
8 

9 
32.0 



7 
8 

9 



0.87 

0.88 
0.89 
0.90 
0.91 
0.92 



0-93 
0.94 

0-95 
0.96 
0.97 

0.98 
0.99 



•03 
.04 

•05 
.06 
.07 

.08 
.09 



•13 
.14 

•15 
.16 

•17 

,18 
,19 



Scale 
Read- 
ing. 



Per 
Cent 



33-5 



7 
8 

9 

34-0 



3 
4 
5 

6 

7 
8 

9 
35-0 

I 
2 

3 
4 

5 

6 

7 
8 

9 
36.0 



22 


9 


^i 


37-0 


24 


I 


25 
26 


2 
3 


27 
28 


4 

5 


29 


6 


30 
31 


7 
8 


32 

34 


9 

38.0 



Scale 1 Per 

Read- Cent 

ing. Fat. 



-34 38-0 



35 
36 
37 
38 
39 

.40 
■ 42 
■43 
■44 

•45 

.46 

-47 
.48 

■49 

.50 

•51 
-52 
-54 
•55 
-56 

-57 
-58 
•59 
.60 
.6i 

.62 
.64 

-65 
.66 
.67 

.68 
.69 
.70 

■71 

,72 

■73 

•75 
.76 
.78 
79 

80 
8i 
82 
84 



39-0 



40.0 



3 
4 

5 

6 

7 
8 

9 
41.0 



42.0 



1-85 

1.87 
1.88 
1.89 
1.90 
1. 91 

1.92 
1-93 
1-94 
1-95 
1.96 

1.98 
1.99 
2.00 
2.02 
2.03 

2.04 
2.05 
2.07 
2.08 
2.09 

2.10 
2.12 

2-13 
2.14 

2.15 

2.16 
2.18 
2.20 

2.21 
2-23 

2.24 
2-25 
2.26 
2.27 
2.28 

2.30 
2.32 

2-33 
2-34 
2-35 

2-37 
2.38 

2-39 
2.40 
2.41 



Scale Per 

Read- I Cent 

ing. I Fat. 



42.5 2.41 



7 
8 

9 
43 -o 



3 
4 

5 

6 

7 
8 

9 
44.0 



2 

3 
4 
5 

6 

7 
8 

9 
45 •© 



7 
8 

9 
46.0 

I 
2 
3 
4 
5 

6 

7 
8 

9 

47.0 



2-43 
2.44 
2.46 

2.47 
2.49 

2.50 

2.51 
2.52 

2.54 

2-55 

2.56 
2.58 
2.60 
2.61 
2.63 

2.64 
2.65 
2.67 
2.68 
2.70 

2.71 
2.72 
2.74 

2-75 
2.77 

2.78 
2.79 
2.80 
2.82 
2.84 

2.8s 
2.87 
2.88 
2.89 
2.90 

2.92 
2-93 
2-94 
2.96 



3.00 
3.01 
3.02 

3-05 



142 



FOOD INSPECTION AND ANALYSIS. 



PERCENTAGES OF FAT CORRESPONDING TO SCALE READINGS ON THE 
WOLLNY REFRACTOMETER —{Continued). 



Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


ing. 


Fat. 


ing. 


¥a.t. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


47.0 


3-05 


50-5 


3-59 


54-0 


4.18 


57-5 


4-78 


61.0 


5.44 


64.5 


6. 14 


I 


3.06 


6 


3.60 


I 


4.20 


6 


4.80 


I 


5-46 


6 


6.16 


2 


3.08 


7 


3.61 


2 


4-22 


7 


4.82 


2 


5-48 


7 


6.18 


3 


3.10 


8 


3-63 


3 


4-23 


8 


4.84 


3 


5-50 


8 


6.20 


4 


3-12 


9 


3-64 


4 


4-25 1 


9 


4.86 


4 


5-52 


9 


6.22 


5 


3-14 


51.0 


3-66 


5 


4.26 


58.0 


4.88 


5 


5-54 


65.0 


6.24 


6 


3-15 


I 


3-67 


6 


4-28 


I 


4.90 


6 


5-56 


I 


6.27 


7 


3.16 


2 


3.68 


7 


4-29 


2 


4-92 


7 


5-58 


2 


6.29 


8 


3-17 


3 


3-70 


8 


4-31 


3 


4-94 


8 


c;.6o 


3 


6.31 


Q 


3-18 


4 


3-72 


9 


4-33 


4 


4-95 : 


9 


5-61 


4 


6.34 


48.0 


3.20 


5 


3-74 


55-0 


4-35 


5 


4-97 


62.0 


5-63 


5 


6-36 


I 


3-21 


6 


3-76 


I 


4-37 


6 


4-98 


I 


5-65 


6 


6.38 


2 


3-23 


7 


3-78 


2 


4.38 


7 


5.00 


2 


5.66 


7 


6.40 


3 


3-25 


8 


3.80 


3 


4.40 


8 


5.02 


3 


5-68 


8 


6.42 


4 


3-27 


9 


3.82 


4 


4-42 


9 


5 -04 


4 


5-70 


9 


6.44 


5 


3-28 


52.0 


3-84 


5 


4-43 


59-0 


5.06 


5 


5-72 


66.0 


6.46 


6 


3-30 


I 


3-85 


6 


4-44 


I 


5.08 


6 


5-74 






7 


3-32 


2 


3-87 


7 


4-46 


2 


5-10 


7 


5-76 






8 


3-i?> 


3 


3-89 


8 


4.48 


3 


5-11 


8 


5-78 






9 


3-34 


4 


3-90 


9 


4-49 


4 


5-13 


9 


=;.8o 






49.0 


3-36 


5 


3-92 


56.0 


4-51 


5 


5-15 


63.0 


5-82 






I 


3.38 


6 


3-93 


I 


4-53 


6 


5-17 


' I 


5-84 






2 


3-40 


7 


3-95 


2 


4-55 


7 


5-19 


2 


5. 86 






3 


3-42 


8 


3-97 


3 


4-57 


8 


5.20 


' 3 


5-88 






4 


3-43 


9 


3-99 


4 


4-59 


9 


5.22 


4 


5-90 






5 


3-44 


53-0 


4.01 


5 


4.60 


60.0 


5-24 


5 

1 


5-92 






6 


3-45 


1 


4-03 


6 


4.61 


I 


5.26 


6 


5-94 






7 


3-46 


2 


4.04 


7 


4-63 


2 


5.28 


7 


5-96 






8 


3-48 


3 


4.06 


8 


4-65 


3 


5-30 


8 


5-98 






9 


3-5° 


4 


4.07 


9 


4-67 


4 


5-32 


9 


6.00 






50.0 


3-51 


5 


4.09 


57-0 


4.69 


5 


5-34 


64.0 


6.02 






I 


3-53 


6 


4.10 


I 


4.71 


6 


5-36 


I 


6.04 






2 


3-55 


7 


4.12 


2 


4-73 


7 


5-38 


i 2 


6.07 






3 


3-56 


8 


4.14 


3 


4-75 


8 


5-40 


3 


6.09 






4 


3-57 


9 


4.16 


4 


4.76 


9 


5-42 


4 


6.12 






5 


3-59 


54-0 


4.18 


5 


4.78 


61.0 


5-44 


5 


6.14 







The following table is of use for those who wish to employ the 
Wollny method, but have the Abbe refractometer instead of the milk-fat 
refractometer. 



MILK. 



143 



INDICES OF REFRACTION (n/,) CORRESPONDING TO SCALE READINGS O? 
THE WOLLNY MILK-FAT REFRACTOMETER. 



Refrac- 
tive 
Index, 



Fourth Decimal of n , 



Scale Readings 



1-333 
1-334 1 






0.0 


0. 1 


0. 2 


0-3 
1.2 


0.4 
1-3 


0-5 
1-4 


C 


0.6 


0-7 


' ' o'.8 * 


0-9 


I.O 


I.I 


1-5 


1.6 


^■35S 


1-7 


1.8 


1-9 


2.0 


2.1 


2.1 


2.2 


2-3 


2-4 


2-5 


1-336 


'■i 


2-7 1 


2.8 


2-9 


3-0 


3-1 


3- - 


3-3 


3-4 


3-5 


1-337 i 


3-6 


3-7 


3-7 


3-8 


3-9 


4.0 


4-1 


4-2 


4-3 


4-4 


1-338 


4-5 


4-6 


4-7 


4-8 


4-9 


5-0 


5-1 


5-2 


5-3 


5-4 


1-339 


5-5 


5-6 


5-7 


5-8 


5-9 


6.0 


6.1 


6.2 


6.3 


6.4 


1-340 


6-5 


6.6 


6-7 


6.8 


6.9 


• 6.9 


7-0 


7-1 


7-2 


7-3 


1-341 


7-4 


7-5 


7-6 


7-7 


7-8 


7-9 


8.0 


8.1 


8.2 


8.3 


1-342 


8.4 


8-5 


8.6 


8-7 


8.8 


8.9 


9-0 


9-1 


9-2 


. 9-3 


1-343 


9-4 


0-5 


9.6 


9-7 


9.8 


9-9 


10. 


10. 1 


10.2 


10.3 


1-344 


10.4 


10.5 


10.6 


10.7 


10.8 


10.9 


II. 


II. I 


II. 2 


11-3 


1-345 


II. 4 


II. 5 


11-5 


II. 6 


II. 7 


II. 8 


II. 9 


12.0 


12. I 


12.3 


1-346 


12.3 


12.4 


12-5 


12.6 


12-7 


12.8 


12.9 


13.0 


13-1 


13-2 


1-347 


^3-3 


13-4 


13-5 


13-6 


13-7 


13.8 


13-9 


14.0 


14. I 


14.2 


1-348 


14-3 


14.4 


14-5 


14.6 


14-7 


14.8 


14-9 


15-0 


15-1 


15-2 


1-349 


15-3 


15-4 


15-5 


15-6 


15-7 


15-8 


15-9 


16.0 


16. I 


16.2 


1-350 


16.3 


16.4 


16.5 


16.6 


16.7 


16.8 


16.9 


17.0 


17-1 


17.2 


1-351 


17-3 


17-4 


17-5 


17.6 


17.7 


17.8 


17.9 


18.0 


18. I 


18.2 


1-352 


18.3 


18.4 


18.5 


18.6 


18.7 


18.8 


18.9 


19.0 


19.1 


19.2 


1-353 


19-3 


19-4 


19-5 


19.6 


19.7 


19.8 


19.9 


20.0 


20.1 


20.2 


1-354 


20.3 


20.4 


20.5 


20.6 


20.7 


20.8 


20.9 


21.0 


21. I 


21.2 


1-355 


21-3 


21.4 


21-5 


21.6 


21.7 


21.8 


21.9 


22.0 


22.1 


22.2 


1-356 


22.3 


22.4 


22.5 


22.6 


22.7 


22.8 


22.9 


23-0 


23.1 


23.2 


1-357 


23-3 


23-4 


23-5 


23.6 


23-7 


23.8 


23-9 


24.0 


24.1 


24.2 


1-358 


24-3 


24-4 


24-5 


24.6 


24-7 


24.8 


24.9 


25.0 


25.1 


25.2 


1-359 


25-3 


25-4 


25-5 


25.6 


25-7 


25-8 


25-9 


26.0 


26.1 


26.2 


1-360 


26.3 


26.4 


26.5 


26.6 


26.7 


26.8 


26.9 


27.0 


27.1 


27-3 


1. 361 


27-4 


27-5 


27.6 


27.7 


27.8 


27-9 


28.0 


28.1 


28.2 


28.3 


1-362 


28.4 


28.5 


28.6 


28.7 


28.8 


28.9 


29.0 


29.1 


29.2 


29-3 


1-363 


29-4 


29-5 


29.6 


29-7 


29.8 


29-9 


30.0 


30.1 


30.2 


30.3 


1-364 


30-4 


30-5 


30.6 


30.7 


30.8 


31-0 


31-1 


31.2 


31-3 


31-4 


1-365 


31-5 


31-6 


31-7 


31.8 


31-9 


32.0 


32.1 


32.2 


32.3 


32-4 


1-366 


32-5 


32-7 


32-8 


32-9 


33-0 


33-1 


33-2 


33-3 


33-4 


33-5 


1-367 


33-6 


33-7 


33-8 


33-9 


34-0 


34-2 


34-3 


34-4 


34-5 


34-6 


1-368 


34-7 


34-8 


34-9 


35-0 


35-1 


35-2 


35-3 


35-4 


35-5 


35-6 


1-369 


35-7 


35-8 


36.0 


36-1 


36.2 


36-3 


36-4 


36-5 


36.6 


36-7 


1-370 


36-8 


36-9 


37-0 


37-1 


37-2 


37-3 


37-4 


37-6 


37-7 


37-8 


1-371 


37-9 


38-0 


38-1 


38.2 


38-3 


38-4 


38.5 


38.6 


38-7 


38.8 


1-372 


38-9 


39-0 


39-2 


39-3 


39-4 


39-5 


39-6 


39-7 


39-8 


39-9 


1-373 


40.0 


40.1 


40.2 


40-3 


40.4 


40.5 


40.7 


40.8 


40.9 


41.0 


1-374 


41-1 


41.2 


41-3 


41.4 


41-5 


41.6 


41.8 


41.9 


42.0 


42.1 


1-375 


42.2 


42.3 


42.4 


42-5 


42.6 


42.7 


42.8 


42.9 


43 -o 


43-1 


1-376 


43-2 


43-3 


43-4 


43-6 


43-7 


43-8 


43-9 


44.0 


44-1 


44.2 


1-377 


44-3 


44-4 


44-6 


44-7 


44-8 


44-9 


45-0 


45-1 


45-2 


45-3 


1-378 


45-4 


45-6 


45-7 


45-8 


45-9 


46.0 


46.1 


46.2 


46-3 


46.4 


1-379 


46.6 


46.7 


46.8 


46-9 


47.0 


47-1 


47-2 


47-3 


47-4 


47.6 



144 




lOOD INSriiCTtON /iND ANALYSIS. 








INDICES OF REFRACTION ( 


«/,) CORRESPONDING TO SCALE READINGS Ot 




THE 


WOLLNY MILK-FAT REFRACTOMETER- 


—{Continued). 




Rofrac- 








Fourth Decimal of w^. 








livc 




















Iniicx, 






















"O- 





1 


2 


3 


4 


6 


6 


7 


8 


9 












1 
Scale Readings. 








I.3S0 


47-7 


47-8 


47-0 


48.0 


48.1 


48.2 


48.3 


48.4 


48.6 


48-7 


1.381 


48.8 


48.9 


49.0 


49-1 


49-2 


49-3 


49-4 


49-6 


49-7 


49-8 


1.382 


49.9 


50.0 


SO- 1 


50 -2 


50-3 


50-4 


50.6 


50-7 


50-8 


50-9 


1-383 


51-0 


51 -I 


51.2 


51-3 


51-4 


51.6 


51-7 


51.8 


51-9 


52.0 


1.384 


52-1 


52.2 


52-3 


52-4 


52.6 


52-7 


52.8 


52.9 


53 -o 


53-1 


1-385 


53-2 


53-3 


53-4 


53-6 


53-7 


53-8 


53-9 


54-0 


54-1 


54-2 


1.386 


54-3 


54-4 


54-6 


54-7 


54-8 


54-9 


55-0 


55-1 


55-2 


55-3 


1-387 


55-4 


55-6 


55-7 


55-8 


55-9 


t;6.o 


56-1 


56.2 


56-3 


56-5 


1.388 


56.6 


56-7 


56.8 


56-9 


57-1 


57-2 


57-3 


57-4 


57-6 


57-7 


I-38CJ 


57-8 


57-9 


58.0 


58.1 


58.2 


58.3 


58-4 


58-6 


58.7 


58.8 


1-390 


58.9 


59-0 


59.1 


59-2 


59-4 


59-5 


59-6 


59-8 


59-9 


60.0 


I-391 


60.1 


60.2 


60.3 


60.4 


60.6 


60 -7 


60-8 


60.9 


61.0 


61. 1 


1.392 


61.3 


61.4 


61.5 


61.6 


61.8 


61.9 


62.0 


62.1 


62-2 


62.3 


1-393 


62.4 


62.6 


62.7 


62.8 


62.9 


63.0 


63 - 2 


63-3 


63-4 


63-5 


1-394 


63.6 


63.8 


63-9 


64.0 


64. 1 


64.2 


64-4 


64.5 


64.6 


64.7 


1-395 


64.8 


65.0 


65.1 


65.2 


65-3 


65.4 


6s -6 


65-7 


65-8 


65-9 


1.396 


66.0 


66.2 


66.3 


66.4 


66.5 


66.6 


66.8 


66.9 


67.0 


67.1 


1-397 


67.2 


67-4 


67-5 


67.6 


67.7 


67.8 


67.9 


68.1 


68.2 


68.3 


1.398 


68.4 


68.6 


68.7 


68.8 


68.9 


6() . 


6() . 1 


69-3 


69.4 


69 -5 


1-399 


69.6 


69.8 


69.9 


70-0 


70.1 


70-2 


70.4 


70-5 


70.6 


70.8 


1.400 


70.9 


71.0 


71. 1 


71.2 


71-4 


71-5 


71.6 


71-8 


71.9 


72.0 


1.401 


72.1 


72.2 


72.4 


72-5 


72.6 


72.8 


72-9 


73-0 


73-1 


73-2 


1.402 


73-4 


73-5 


73-6 


73-8 


73-9 


74.0 


74-1 


74-2 


74-4 


74-5 


1.403 


74-6 


74.8 


74-9 


75 -o 


75-1 


75-2 


75-4 


75-5 


75-6 


75-8 


1.404 


75-9 


76.0 


76-1 


76.2 


76.4 


76-5 


76.6 


76.8 


76.9 


77.0 


1.405 


77-1 


77-2 


77-4 


77-5 


77-7 


77-8 


77-9 


78.1 


78.2 


78.3 


1.406 


78.5 


78.6 


78.7 


78.8 


79-0 


79.1 


79-2 


79-4 


79-5 


79-6 


1.407 


79.8 


79-9 


80.0 


80.1 


80.2 


80.4 


80.5 


80.6 


80.8 


80.9 


1.408 


81.0 


81. 1 


81.2 


81.4 


81.5 


81.6 


81.7 


81.9 


82-0 


82.1 


1.409 


82.3 


82.4 


82. 5 


82.6 


82.8 


82.9 


83.0 


83.2 


83-3 


83.4 


1.410 


83.6 


83-7 


83.8 


84.0 


84., 


84. 2 


84.4 


84.5 


84.6 


84.8 


1.411 


84.9 


8t;.o 


8^.2 


85-3 


85.4 


85-5 


8s. 6 


85.7 


85-9 


86.1 


1.412 


86.2 


86.3 


86.5 


86.6 


86.7 


86.9 


87.0 


87.1 


87-3 


87.4 


1-413 


87-5 


87-7 


87.8 


87-9 


88.1 


88.2 


88.3 


88.5 


88. () 


88.7 


1-414 


88.9 


89.0 


89.1 


8g-3 


89.4 


89.6 


89-7 


89-9 


90.0 


90. t 


1-415 


90.2 


90.4 


90-5 


()0 - 6 


90 . 8 


90.9 


91.0 


91.2 


91-3 


9I-S 


1.410 


() 1 . 6 


1)1-7 


91.9 


92.0 


92-1 


92-3 


92-4 


92.5 


92.7 


92.8 


1-117 


9. '.9 


93-1 


93-2 


93-3 


93-5 


93-6 


93-8 


93-9 


94-0 


94.2 


1.418 


94-3 


94-4 


94-6 


94-7 


94.8 


05 -O 


95 • I 


95-3 


95-4 


95-6 


1.419 


95-7 


95-8 


96.0 


96.1 


96.3 


9'' -4 


9().6 


96.7 


96.8 


97.0 


1.420 


97-1 


97-3 


97-4 


97-6 


97-7 


07-8 


g8.o 


98.1 


98-3 


98.4 


1.421 


98.5 


98.7 


98.8 


99.0 


99-1 


99-3 


99-4 


99-5 


99-7 


99.9 


1.422 


too. 





















MILK. 145 

Determination of Proteins. -For determination of the total nitro- 
gen in milk, 5 cc. are measured direct into a Kjeldahl digestion- flask, 
or a known weight from a weighing-bottle may be used, and the regular 
Gunning method is employed as described on page 69, proceeding with 
the digestion at once without evaporation. 

The total nitrogen, multiphed by 6.38, gives the total proteins. By 
many the old factor of 6.25 is still employed, but in view of the fact that 
both casein and albumin have been found to contain 15.7% of nitrogen, 
there would seem to be the best reasons for employing 6.38 as a factor 



(^.)' 



Ritthausen's Method. — Ten grams of milk are measured into a beaker 
and diluted with water to about 100 cc. Five cc. of a solution of copper 
sulphate (strength of Fehling's copper solution, 34.64 grams CuSO^ in 500 cc. 
of water) are added and the mixture stirred. A solution of sodium hydrox- 
ide (25 grams to the liter) is added cautiously a little at a time, till the 
liquid is nearly, but not quite neutral, avoiding an excess of alkali, as 
this would prevent the complete precipitation of the i)roteins. Allow the 
precipitate to settle, and pour off the supernatant liquid through a weighed 
filter, previously dried at 130° C. Wash a number of times by decantation, 
ind transfer the precipitate to the fdter, being careful to remove the por- 
tions adhering to the sides of the beaker with a rubber-tipped rod. Wash 
thoroughly with water, and drain dry, after which the precipitate is washed 
BV'ith strong alcohol, dried, extracted with ether, preferably in a Soxhlet 
extractor, and then transferred on the filter to the oven, dried at 130° C, 
ind weighed. The filter and precipitate are then burnt to an ash in a 
porcelain crucible, and the weight of the residue subtracted from the first 
sveight gives that of the jjroteins. 

Richmond * recommends modifying this process to the extent of 
neutralizing the milk, using phenolphthalein as an indicator, before adding 
the copper sulphate solution, and using only 2.5 cc. of the latter. 

Determination of Casein. — Official Method oj the A. O. A. C. — Ten 
grams of the milk are placed in a beaker, and made up with water to about 
100 cc. at 40° to 42° C. One and one-half cc. of a 10% solution (by weight) 
of acetic acid are added, the mixture stirred, warmed to the above tem- 
perature, and allowed to stand for from three to five minutes, till a floccu- 
lent precipitate separates, leaving a clear supernatant hquid. Decant 

* Dairy Chem., p. 107. 



146 FOOD INSPECTION /IND ANALYSIS. 

upon a filter, wash with cold water two or three times by decantation, 
and finally transfer the v/hole of the precipitate to the filter, and, aftei 
filtering, wash two or three times. The filtrate should be clear or nearly 
so. If not, it can generally be made so by repeated filtrations, and the 
washing done afterwards. The filter containing the washed precipitate 
is transferred to the Kjeldahl digestion-flask and the nitrogen obtained 
by the Gunning process. Nx 6.38 = casein. 

Determination of Albumin. — Optional Methods of the A.O. A. C. — To 
the filtrate from the direct determination of casein by the acetic acid 
method as described in the preceding section, exactly neutralized with 
sodium hydroxide, 0.3 cc. of a io^/(, solution of acetic acid is added, 
and the mixture is boiled till the albumin is completely precipitated. 
The precipitate is collected on a filter and washed, the nitrogen being 
determined in the precipitate, and the factor 6.38 used in calculating 
the albumin therefrom. 

Lefjman and Beam's Modified Method j or Albumin and Casein. — Owing 
to the tedious processes of washing and filtering incidental to the above 
methods for determining casein, the following is suggested. Twenty cc. of 
the milk are mixed with saturated magnesium sulphate solution, and 
the mixture saturated with the powdered salt. The whole is then washed 
into a graduate with a little of the saturated solution, and the precipitate 
allowed to settle, leaving a clear supernatant layer. The volume of 
the mixture in the graduate is read, and as much as possible of the clear 
portion is withdrawn by a pipette and filtered. 

An aliquot part of the filtrate is then taken, and the albumin is precip- 
itated from it by a solution of tannin, after which the precipitate is washed 
in a filter and the nitrogen determined therein. Nx 6.38 = albumin. 

The casein is calculated by difference between the total proteins and 
the albumin. 

Determination of Nitrogen as Caseoses, Amido-compounds, Peptones, 
and Ammonia. — Van Slyke * proceeds as follows: The filtrate from 
the determination of the albumm, as above, is heated to 70° C, i cc. of 
50% sulphuric acid is first added, and aftei^'ards chemically pure zinc 
sulphate to saturation. The mixture is allowed to stand at 70° until the 
caseoses separate out and settle. Cool, filter, wash with a saturated zinc 
sulphate solution slightly acidified with sulphuric acid, and determine 
the nitrogen of the caseoses in the precipitate. 

* N, Y. Exp. Station, Bui. 215, p. 102. 



MILK. 



147 



For A::iido-com pounds and Ammonia treat 50 grams of the milk in a 
J50-CC. graduated flask with i gram sodium chloride and a 12% solution 
)f tannin, added drop by drop till no further precipitate is formed. Dilute 
o the 250-cc. mark, shake, and filter. Determine the nitrogen in 50 cc. 
)f the filtrate, the result being the combined nitrogen of the amido-com- 
jounds and ammonia. 

Distil with magnesium oxide 100 cc. of the filtrate from the tannin salt 
lOlution, receiving the distillate in a standardized acid, and titrating in 
he usual way for the ammonia. 

Calculate the nitrogen of the peptones by subtracting from the total 
litrogen that due to all other forms. 

Van Slyke has furnished the following unpublished analysis of a 
ample of milk three months old, kept under antiseptic conditions by 
:hloroform. 



Per Cent Per Cent 
Total N. Sol. Nitrogen. 


Per Cent 

N as Paranviclein. 

Caseoses, and 

Peptones. 


Per Cent 
N as Amides. 


0.561 i 0.099 

1 


0.074 


0.025 



Determination of Milk Sugar.— if a polariscope is available, the 
ugar of milk can most readily and conveniently be determined by 
tptical methods. In the absence of a polariscope, the reducing power of 
nilk sugar on copper salts may be utilized quite accurately in deter- 
nining the sugar, using either volumetric or gravimetric methods as 
lesired. 

Determination by Optical Methods. — i. Reagents. — Acid Nitrate 0} 
\lercury. — This solution is prepared by dissolving metallic mercury 
n twice its weight of nitric acid of specific gravity 1.42, and adding to 
he solution an equal volume of water. One cc. of this reagent will be 
ound sufficient to precipitate the proteins and fat completely from 65 grams 
if milk, but if more is employed the result of the analysis is not affected. 

Mercuric Iodide Solution. — 33.2 grams of potassium iodide are mixed 
vhh. 13.5 grams of mercuric chloride, 20 cc. of acetic acid, and 640 cc. 
ff water. 

Suhacetate of Lead Solution, U. S. P. See p. 586. 

Notes. — For the Laurent polariscope, in which the normal weight 
or sucrose is 16.19 grams, the corresponding normal weight for lac- 
ose is 20.496, while for the Soleil-Ventzke instrument, in which the su- 



148 



FOOD INSTECTION AND ANALYSIS. 



crose normal weight is 26.048 grams, the corresponding lactose normal 
weight is 32.975.* 

It is customar}' to employ three times the normal weight of milk 
in the case of the Laurent instrument (viz., 61.48 grams) and twice the 
normal weight in the case of the Soleil-Ventzke (viz., 65.95 grams). 

As it is more convenient to measure the milk than to weigh it, and 
as the volume varies with the specific gravity, the following table is use^ 
ful, showing the quantity to be measured in any case, having first deter- 
mined the specific gravity. 



Specific Gravity. 


Volume of Milk to be Used. 


For Polariscopes of 

which the Sucrose 

Normal Weight is 

16.19 Grams. 


For Polariscopes of 

which the Sucrose 

Normal Weight is 

26.048 Grams. 


1.024 
1.026 
1.028 
1.030 
1.032 
1-034 
I -035 


60.0 cc. 
59-9 CC. 
59.8 cc. 
59-7 cc. 
59.6 cc. 
59-5 cc. 
59-35 cc. 


64.4 CC. 
64.3 CC. 
64. 15 CC. 
64.0 cc. 
63.9 cc, 
63.8 cc. 
63-7 cc. 



For ordinary work it is sufficiently close to have a pipette gradu- 
ated to deliver 59.7 cc. if the Laurent instrument is used, and 64 cc. for 
the Soleil-Ventzke. 

2. Process. — Measure as above, the equivalent of 61.48 grams of 
the milk for the Laurent, or 65.95 grams for the Soleil-Ventzke, instru- 
ment into a loo-cc. graduated flask, add, in order to clarify, 2 cc. of acid 
nitrate of mercur)^ solution, or 30 cc, of mercuric iodide solution, or 10 cc. 
of lead subacetate solution. Shake gently and fill to the mark with 
■water. Then add from a pipette enough water to make up for the volume 
of the precipitated proteins and fat, insuring 100 cc. of sugar solution. 
If the Laurent instrument is used, the amount added as prescribed by 
the A. O. A. C. is 2.4 cc, and with the Soleil-Ventzke 2.6 cc. The con- 
tents of the flask are then shaken and poured upon a dr\^ filter. The 
filtrate, which should be perfectly clear, is polarized in a 200-mm. tube, 
and the reading, divided by 3 for the Laurent and by 2 for the Soleil- 
Ventzke, gives the percentage of lactose directly. 

Allowance for the Volume of the Precipitate. — This of course varies 

* [a]D for lactose= 52.53, [ajp for sucrose=66.5, hence for the Laurent instrument 

52.53 : 66.5 ;; 16.19 : 20.496, 
and for the Soleil-Ventzke instrument 52.53 : 66.5 ;: 26.048 : 32.975. 



J 



MILK. 149 

with the content in proteins, and fat, and while the above allowance gives 
in most cases sufficiently close results, it is not exact. Leffman and 
Beam * advise that the amount of water to be added above 100 cc. be 
calculated in each case from the percentage of proteins and fat previously 
found by analysis, multiplying the actual weight of the fat in grams in 
the sample taken by 1.075, ^^^ ^^^ weight of proteins, by 0.8, the sum 
of the two results being the volume in cubic centimeters occupied by 
the precipitate. 

All the calculations are avoided by employing the double-dilution 
method, which is to be recommended when very particular results are 
required. 

Wiley and Ewell's Double-dilution Method.j — Two flasks are em- 
ployed graduated at 100 and 200 cc. respectively, into each of which 
are introduced 65.95 grams of milk, if the Soleil-Ventzke instrument is 
used (or 61.48 grams in case the Laurent is used) and 4 cc. of the mer- 
curic nitrate solution are added, both flasks being filled to the mark and 
shaken. The contents are filtered and the polarization is made in each 
case in a 400-mm. tube. 

The second reading (that of the more dilute solution) is multiplied 
by 2, and the product subtracted from the first reading; the remainder 
is then multiplied by 2, and the product subtracted from the first read- 
ing (that of the stronger or 100 cc. solution). The result is the cor- 
rected reading, which, divided by 4, gives the exact per cent of milk sugar 
in the sample. This method depends on the fact that within ordinary 
limits the polarizations of two solutions of the same substance are 
inversely proportional to their volumes. 

Determination of Milk Sugar by Feeling's Solution.— Twenty- 
five grams of the milk (24.2 cc.) are transferred to a 250-cc. flask, 0.5 cc. of 
a 30% solution of acetic acid are added and the contents well shaken. 
After standing for a few minutes, about 100 cc. of boiling water are run 
in, the contents again shaken, 25 cc. of alumina cream are next added, 
the flask shaken once more, and set aside for at least ten minutes. The 
supernatant liquid is then poured upon a previously wetted ribbed filter, 
and finally the whole contents of the flask are brought thereon, and the 
filtrate and washings made up to 250 cc. The filtrate must be perfectly 
clear. The milk sugar in a solution thus precipitated would ordinarily 
not exceed ^ of i per cent. 

* Milk and Milk Products, p. 38. 

t Wiley's Agricultural Analysis, p. 278; Analyst, 21, 1896, p. 182. 



ISO FOOD INSPECTION AND ANALYSIS. 

Volumetric Fehling Process. — From a burette containing the clear 
milk sugar solution above prepared, run a measured volume into the 
boiling Fehling liquor containing 5 cc. each of copper and alkali solution 
till sufficient has been introduced to completely reduce the copper, con- 
ducting the operation in the manner described in detail on page 591, 

As 0.067 gram of milk sugar will reduce 10 cc. of Fehling solution 

(see p. 593), it follows that the number of cubic centimeters of sugar- » 

containing solution required for making the test (using preferably the! 

average of several determinations) will contain 0.067 gram of milk' 

sugar, from which the percentage is readily computed. Thus if 16 cc. 

of the milk sugar solution are necessary to reduce the copper, then 16 

cc. contain 0.067 gram milk sugar. 

250 cc. of solution contain 25 grams milk, 

ICC. " " " o.i " 

i6cc. " " " 1.6 " 

and 1.6 grams milk contain 0.067 gram milk sugar. Therefore the 

.067X100 _ 

sample contams ■ = 4.19%. 

Gravimetric Fehling Processes. — O^Sulllvan-Defren Method. — Twenty- 
five cc. of the above milk sugar solution are added to the hot mixture of 
I :; cc. each of Fehling copper and alkali solutions and 50 cc. water, pre- 
pared as directed on page 591. and the test carried out in accordance with 
the details there described. The weight of the cupric oxide, CuO, as 
formed, may be roughly calculated to anhydrous milk sugar by multiply- 
ing by 0.6024. 

For more accurate results, however, the Defren table, page 595, should 
be used. 

Soxhlet^s Method."^ — Twenty-five cc. of milk are diluted with 400 cc. 
t»f water in a half-liter graduated flask and 10 cc. of Fehling's copper solu- 
tion are added. Then 8.8 cc. of half-normal sodium hydroxide are am in, 
or a sufficient quantity to nearly but not quite neutralize, the solution 
being still slightly acid. The flask is filled to the mark, shaken, and the 
contents filtered, using a dry filter. 

One hundred cc. of the filtrate are added to 50 cc. of the mixed Fehling 
solution, which is boiled briskly in a beaker (using 25 cc. each of the 
copper and alkali solution), .\fter boiling for six minutes, filter rapidly 
through a Gooch crucible provided with a layer of asbestos as described on 
page 594, and wash with boiling water till free from alkali. The asbestos 

* U. S. Dept. of Agric, Bur. of Chem., Bull. 46, p. 41; Bui. 107 (rev.), p. 119. 



MILK. 151 

film with the adhering cuprous oxide is washed into a beaker by hot dilute 
nitric acid, and after complete solution of the copper is assured, it is again 
filtered and washed with hot water till a clean solution containing all the 
copper is obtained. Add 10 cc. of dilute sulphuric acid (containing 200 cc. 
of sulphuric acid, specific gravity 1.84 per liter) and evaporate on the steam- 
bath till the copper has largely crystallized, then carefully continue the 
heating over a hot plate till the nitric acid is driven out, as evidenced by 
the white fumes of sulphuric. Add 8 or 10 drops nitric acid (specific 
gravity 1.42) and rinse into a very clean tared platinum dish of about 
100 cc. capacity, in which the copper is deposited by electrolysis. See 
page 608. 

The weight of milk sugar is determined from that of copper found, 
from the table on page 152. 

If the apparatus for the determination of the copper by the elec- 
trolytic method is not at hand, the cuprous oxide may be weighed 
directly in the Gooch crucible. In order to facilitate drying, it should 
be washed successively with 10 cc. of alcohol, and 10 cc. of ether, after 
which it is dried thirty minutes in a water-oven at 100° C, cooled, and 
weighed. The weight of copper is obtained from the weight of the 
cuprous oxide by the use of the factor 0.8883. 

Munson and Walker Method. — The milk sugar solution is prepared as 
in Soxhlet's method. For details as to the copper reduction process see 
page 598. 

Relation between Specific Gravity, Fat, and Total Solids of Milk. — 
The close relationship existing between these factors has long been 
known, and many formulae have been devised, whereby, if two of them 
are known, the third may be computed with considerable approach to 
accuracy. The specific gravity and the fat are very readily determined 
by any dair}-man, by the aid of a lactometer and the Babcock apparatus. 
The total solids are ascertained with more difficulty, since the use of more 
involved and costly apparatus is necessary, besides considerable tech- 
nical skill. It is therefore common for producers to calculate the total 
solids from the fat and specific gravity, using one of the many tables pre- 
pared for the purpose, based on some one of the best accepted formulae. 
The total solids can thus be calculated to within two or three tenths of 
a per cent. 

The two most commonly used formulae for this purpose are those of 
Hehner and Richmond in England, and Babcock in the United States. 
Hehner and Richmond's formula is 

7 = 0.255+ i.2F-fo.i4, 



152 



FOOD INSPECTION AND ANALYSIS. 



SOXHLETS TABLE FOR 


THE DETERMIN.\TION OF LACTOSE.* 


Milli- 


1 

Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


of Cop- 


of Lac- , 


of Cop- 


of Lac- 


of Cop- 


of Lac- 


of Cop- 


of Lac- 


of Cop- 


of Lac- 


per. 


tose. 1 


per. 


tose. 


per. 


tose. 


per. 


tose. 


per. 


tose. 


lOO 


71.6 


161 


117. 1 


221 


, 1 

162.7 ; 


281 


209.1 


341 


256-S 


lOI 


72.4 


162 


117. 9 


222 


163.4 


282 


209.9 


342 


257-4 


102 


73-1 


163 


118. 6 


223 


164.2 


283 


210.7 


343 


258.2 


103 


73-8 


164 


"9-4 


224 


164.9 1 


284 


211. 5 


344 


2S9-0 


104 


74.6 


165 


120.2 


225 


165-7 


285 


212.3 


345 


259.8 


105 


75-3 


166 


120.9 


226 


166.4 


286 


213.1 


346 


260.6 


106 


76.1 


167 


121. 7 


227 


167.2 1 


287 


213-9 


347 


261.4 


107 


76.8 


168 


122.4 


228 


167.9 


288 


214.7 


348 


262.3 


108 


77-6 


169 


123.2 


229 


168.6 


289 


215-5 


349 


263.1 


109 


78.3 


170 


123.9 


230 


169.4 ! 


290 


216.3 


350 


263.9 


no 


79.0 


171 


124.7 


231 


170. 1 


291 


217.1 


351 


264.7 


III 


79-8 


172 


125-5 


232 


170.9 


292 


217.9 


352 


265.5 


112 


80.5 


173 


126.2 


233 


171. 6 


293 


218.7 


353 


266.3 


113 


81.3 


174 


127.0 


234 


172.4 i 


294 


219-5 


354 


267.2 


114 


82.0 


175 


127.8 


235 


173-1 ' 


295 


220.3 


355 


268.0 


115 


82.7 


176 


128.5 


236 


173-9 


296 


221 .1 


356 


268. 8 


116 


83-5 


177 


129.3 


237 


174.6 1 


297 


221 .9 


357 


269.6 


117 


84.2 


178 


130-1 


238 


175-4 - 


298 


222.7 


358 


270.4 


118 


85-0 


179 


130.8 


239 


176.2 


299 


223-5 


359 


271.2 


119 


85-7 


180 


131.6 


240 


176.9 


300 


224.4 


360 


272.1 


120 


86.4 


181 


132-4 


241 


177.7 


301 


225.2 


361 


272.9 


121 


87.2 


182 


133-1 


242 


178.5 


302 


225.9 


362 


273 ■ 7 


122 


87-9 


183 


133-9 


243 


179-3 


303 


226.7 


363 


274-5 


123 


88.7 


184 


134-7 


244 


180. 1 


304 


227.5 


364 


275 -3 


124 


89-4 


185 


135-4 


245 


180.8 


305 


228.3 


365 


276.2 


125 


90.1 


186 


136.2 


246 


181. 6 


306 


229.1 


366 


277.1 


126 


90.9 


187 


137.0 


247 


182.4 


307 


229.8 


367 


2779 


127 


91.6 


188 


137-7 


248 


183.2 


308 


230.6 


368 


27S.S 


128 


92-4 


189 


138.5 i 


249 


184.0 


"309 


231-4 


369 


279.6 


129 


93-1 


190 


139-3 


250 


184.8 


310 


232.2 


370 


280.5 


130 


93-8 


191 


140.0 


251 


185.5 


311 


232.9 


371 


281.4 


131 


94-6 


192 


140.8 


252 


186.3 


312 


233-7 


372 


282.2 


132 


95-3 


193 


141.6 


253 


187. 1 


i-^i 


234.5 


373 


283.1 


^2,2, 


96.1 


194 


142.3 


254 


187.9 


314 


235-3 


374 


283.9 


134 


96.9 


195 


143 -I 


255 


188.7 


315 


236.1 


375 


284. 8 


135 


97-6 


196 


143-9 


256 


189.4 


316 


236.8 


376 


285.7 


136 


98-3 


197 


144.6 


257 


190.2 


317 


237-6 


377 


286.5 


137 


99-1 


198 


145-4 


258 


191.0 


318 


238.4 


378 


287.4 


138 


99-8 


199 


146.2 


259 


191.8 


319 


239-2 


379 


288.2 


139 


100.5 


200 


146.9 


260 


192.5 


320 


240.0 


380 


289.1 


140 


101.3 


201 


147-7 


261 


193-3 


321 


240.7 


381 


289.9 


141 


102.0 


202 


148.5 


262 


194.1 


322 


241.5 


382 


290.8 


142 


102.8 


203 


149.2 


263 


194.9 


3^2, 


242.3 


383 


291.7 


143 


103-5 


204 


150.0 


264 


195-7 


324 


-'43 -I 


384 


29-^ -5 


144 


104.3 


205 


150-7 


265 


196.4 


325 


243-9 


385 


293-4 


145 


105. 1 


206 


151-5 


266 


197.2 


326 


244.6 


386 


294.2 


146 


105.8 


207 


152.2 


267 


198.0 


327 


245-4 


387 


295 • I 


147 


106.6 


208 


153-0 


268 


198.8 


328 


246.2 


388 


296.0 


148 


107.3 


209 


153-7 


269 


199-5 


329 


247-0 


389 


296.8 


149 


108.1 


210 


154-5 


270 


200.3 


330 


247-7 


390 


297.7 


150 


108.8 


211 


155-2 


271 


201.1 


22,^ 


248.5 


391 


298.5 


151 


109.6 


212 


156.0 


272 


201.9 


332 


249-2 


392 


299.4 


152 


no. 3 


213 


156.7 


273 


202.7 


333 


250.0 


393 


300.3 


153 


III. I 


214 


157-5 


274 


203-5 


334 


250.8 


394 


301-1 


154 


III. 9 


215 


158.2 


275 


204.3 


335 


251.6 


395 


302.0 


155 


112. 6 


216 


159-0 


276 


205.1 


336 


252.5 


396 


302.8 


156 


113-4 


217 


159-7 


277 


205.9 ' 


337 


253-3 


397 


303-7 


157 


114. 1 


218 


160.4 


278 


206.7 


338 


254-1 


398 


304.6 


158 


114. 9 


219 


161.2 


279 


207.5 


339 


254-9 


399 


305 • 4 


159 


115. 6 


220 


161.9 


280 


208.3 


340 


255-7 


400 


306.3 


160 


116. 4 



















* Wiley, Principles and Practice of Agricultural Analysis, Vol. III. pp. 163-165. 



MILK. 

wheie T is the per cent of total solids, S the lactometer 
reading, and F the fat. An ingenious instrument known 
as Richmond's milk-scale (Fig. 49) is useful in making 
the calculation, instead of employing either the formula or 
a tabic. This is constructed on the principle of the slide 
rule, and by its use the specific gravity may be corrected 
to the proper temperature, and the solids calculated from 
the fat and specific gravity. 

Babcock's formula for solids not fat is as follows : 



Solids not fat ■■ 



looS-FS 



IOC- 



-l)(lOO-F)2.5, 



1.0753/^5 

S being the specific gravity, and F the percentage of 
fat. On this formula he has prepared a table * by means 
of which one may calculate solids not fat agreeing quite 
closely with results obtained by gravimetric analysis.f 
The table on page 154 has been recomputed and enlarged 
from that of Babcock, so as to express results in total 
solids rather than solids not fat. 

Calculation of Proteins. — Van Slyke's { formula for 
calculating proteins {P) from the fat {F) is: 
P=(i^-3)Xo.4+2.8. 

Olsen § has devised the following formula for calcu- 
lating proteins from total solids {TS): 

P=TS-—. 
1-34 
Approximately 0.8 X proteins = casein. 

The proteins being thus calculated, the sugar may be 
computed by difference. These calculations, while only 
approximate, give quite satisfactory results for normal, 
healthy milk, especially from herds. 

Determination of Acidity. — While milk is still fresh, 
i.e., before it has begun to undergo lactic fermentation, 
it will show an acid reaction, which is sometimes expressed 
in terms of lactic acid. In view of the fact that 

* U. S. Dept.of Agric, Div. of Chem., Bui. 47, p. 123; Bui. 107 (rev.) 
p. 225. 

t For approximate work Babcock has suggested the following simpli- 
fied formulae: Solids not fat = o.25G+o.2i^ and total solids=o.25G-f- 
1.2F, G being the lactometer reading and F the fat. 

t Jour. Am. Chem. Soc. 30, igoS, p. 1182. 

§ Jour. Ind. and Eng. Chem., i, 1909, p. 253. 



W 



^ 



lO 



CO 



^^ 



^CD 



L 



-Oi\ 



't 



!co 



P 




••^ 



JQ 



J CD 



p^ 



154 



FOOD INSPECTION yIND ANALYSIS. 



TABLE SHOWING PER CENT OF TOTAL SOLIDS IN MILK CORRESPONDING 
TO QUEVENNE LACTOMETER READINGS* AND PER CENT OF FAT.f 



Per 

Cent 












Lactometer Reading at i 


5-5° C. 




























1 


of Fat. 


23 


23 


24 


25 


26 


27 


28 


29 


30 


31 


32 


33 


34 


35 1 36 


o.o 


5 -SO 


5.75 


6.00 


6.25 


6. 50 


6.75 


7 .00 


7.2s 


7-50 


7-75 


8.00 


8.2s 8.50 


8.7s! 9.00 


o.x 


S.62 


5.87 


6.12 


6.37 


6.62 


6.87 


7.12 


7.37 


7.62 


7-87 


8.12 


8.37 8.62 


8.87 9.1.. 


O. 3 


5-74 


5-99 


6. 24 


6.49 


6.74 


6.99 


7.24 


7.49 


7-74 


7-99 


8.24 


8.49 8.74 


8.99 


9.24 


0.3 


S-86 


6. II 


6.36 


6.61 


6.86 


7. II 


7 -.56 


7.61 


7.86 


8. II 


8.36 8.61I 8.86 


9. II 


936 


0.4 


5 .08 


6.23 


6.48 


6.73 


6.98 


7.23 


7-48 


7-73 


7-98 


8.23 


8.48 


8.73 8.99 


9 .23 


9-48 


o.S 


6. 10 


6.35 


6.60 


6.85 


7.10 


7.3; 


7 .60 


7-85 


8.10 


8.35 


8.60 


8.85 9.10 


9-35 


9.60 


0.6 


6.22 


6.47 


6.72 


6.97 


7.22 


7.47 


7.72 


7-97 


8.22 


8.47 


8.72 


8.97 9.22 


9-47 


9-72 


0.7 


6.34 


6.59 


6.84 


7.09 


7.34 


7.59 


7.84 


8.09 


8.34 


8.59 


8.84 


9 . 09 9 . 34 


9-59 


9.84 


0.8 


6.46 


6.71 


6.96 


7.21 


7-46 


7.71 


7.96 


8.21 


8.46 


8.71 


8.96 


9.21 9.46 


9-71 


9.96 


0.9 


6.58 


6.83 


7.08 


7-33 


7.58 


7.83 


8.08 


8.33 


8.58 


8.83 


9.08 


9-33 9.58 


9.83 10.08 


1 .0 


6. 70 


6.95 


7. 20 


7-45 


7.70 


7-95 


8.20 


8.45 


8.70 


8.95 


9. 20 


9. 45 9-70 


9.95(10. 20 


I.I 


6.82 


7.07 


7.32 


7-57 


7.82 


8.07 


8.32 


l-v 


8.82 


9-07 


9-32 


9.571 9.82 


10.07110. 32 


1.2 


6.94 


7.19 


7-44 


7.69 


7-94 


8.19 


8.44 


8.69 


8.94 


9.19 


9-44 


9.69I 9.94 


1 . 1 9 1 . 44 


1.3 


7.06 


7.31 


7.56 


7.81 


8.06 


8.31 


8.56 


8.81 


9.06 


9 31 


9 -56 


9. 81 ' 10. 06 


10.31:10.56 


1.4 


7.18 


7-43 


7.68 


7.93 


8.18 


8.43 


8.68 


8.93 


9.18 


9-43 


9-68 


9.93;io.i8 


io.43|io.68 


i.S 


7.30 


7.55 


7.80 


8.05 


8.30 


8.55 


8.80 


9.05 


9 30 


9-55 


9 -So 


10.05 10. 30 


10.55 10.80 


1.6 


7.42 


7.67 


7.92 


8.17 


8.42 


8.67 


8.92 


9.17 


9.42 


9.67 


9-82 


10. 1710. 42 


10.67110.92 


1.7 


7-54 


7.79 


8.04 


8. 29 


8.54 


8.79 


9-04 


9.29 


9-54 


9-79 


10.04 


10. 29' 10. 54 


10. 79'i I .04 


1.8 


7.66 


7.91 


8.16 


8.41 


8.66 


8.91 


9. 16 


9.41 


9-66 


9. 91 


10.16 


10.41 jio.66j 10.91111 . 17 


1.9 


7.78 


8.03 


8.28 


8.53 


8.78 


9.03 


9.28 


9.53 


9.78 


10.03 


10.28 


10.5s 10.78 1r.04l11.29 


2.0 


7.90 


8.15 


8.40 


8.65 


8.90 


9.15 


9.40 


9.6s 


9.90 


10. IS 


10.40 


io.66'io.9i II. 16 II. 41 


2. 1 


8.02 


8.27 


8.52 


8.77 


9.02 


9.27 


9. 52 


9.77 


10.02 


10.27 


10.52 


10.78i11.03 ii.28]ii.53 


2. 2 


8.14 


8.39 


8.64 


8.89 


9.14 


9-39 


9-64 


9.89 


10.14 


10.39 


10.64 


io.9o!ii . 15 II .40 


II .65 


2.3 


8.26 


8.51 


8.76 


9.01 


9.26 


9.51 


9.76 


10.01 


10. 26 


10.51 


10.76 


1 1 . 02J 1 1 . 27 11.52 


11.77 


2.4 


8.38 


8.6? 


8.88 


9.13 


9.38 


9.63 


9.88 


10.13 


10.38 


10.63 


10.88 


1 1 . 14I1 1 .39 II .64 


11.89 


2.S 


8.50 


8.75 


9.00 


9.25 


9.50 


9-75 


10.00 


10. 25 


10. 50 


10.75 


II .00 


II . 26 1 1 . 51 II .76112.01 


2.6 


8.60 


8.87 


9.12 


9-37 


9.62 


9.87 


10.12 


10.37 


10.62 


10.87 


tl.I2 


ii.38'ii.63|ii.88 12.13 


2.7 


8.74 


8.99 


9.24 


9-49 


9-74 


9.99 


10. 24 


10.49 


10.74 


10.99 


11.24 


II . 5o!i I . 75:12. 00I12. 25 


2.8 


8.86 


9. II 


9.36 


9.61 


9.86 


10. II 


10.36 


10.61 


10.86 


11 .11 


11.37 


II .62 


II .87 12.12I12.37 


2.9 


8.98 


9-23 


9.48 


9.73 


9.98 


10.23 


10.48 


10.73 


10.98 


11.23 


11.49 


11.74 


11.99 12.24 1 2 . 49 

1 


30 


9. 10 


9-35 


9.60 


9-85 


10. 10 


10.35 


10.60 


10.85 


II . 10 


11.36 


11.61 


11.86 


12. II 12.36 12.61 


31 


9. 22 


9.47 


9.72 


9.97 


10. 22 


10.47 


10.72 


10.97 


11.23 


11.48 


11.73 


11.98 


12.23 12.48,12.74 


3-2 


9-34 


9-59 


9-84 


10 .09 


10.34 


10.59 


10.84 


I ' .09 


11.35 


II .60 


11.85 


12.10 I2.35li2.6i|i2.86 


3-3 


9.46 


9-71 


9.96 


10.21 


10.46 


10.71 


10.96 


11.22 


11.47 


11.72 


11.97 


12.22 12.48 12.73 12.98 


3-4 


9-S8 


9-83 


10.08 


10.33 


10.58 


10.83 


II .09 


11.34 


ii-SO 


11.84 


12.09 


12.34 12.60112.85,13. 10 


3-5 


9.70 


9-95 


10. 20 


10-45 


10. 70 


10. 95 


II . 21 


11.46 


II. 71 


II .96 


12.21 12.46 12.72 12.97 13.22 


3.6 


9.82 


10.07 


10.32 


10.57 


10.82 


11.08 


11.33 


11.58 


11.83 


12.08 


12.3.3I12.58 l2.84li3-09!i3-34 


3-7 


9-94 


10. 29 


10.44 


10.79 


10.94 


1 1 . 20 


II. 45 


I 1 . 70 


11-95 


I 2 . 20 


I 2.45 I 2.70 12 .96 


13-21 13.46 


3.8 


10.06 


10.31 


10.56 


10.81 


II .06 


11.32 


11-57 


11.82 


12.07 


12.32 


12.57 12.82 13.08 


13-3313-58 


3-9 


10.18 


10.43 


10.68 


10.93 


II. 18 


11.44 


II .69 


11.94 


12.19 


12.44 


12.69 12.94 13.20 

1 


13-45 13-70 


4.0 


10.30 


10-55 


10.80 


II .05 


11.30 


11.56 


II. 81 


I 2.06 


12.31 


12.56 


12.81 13.06 13.32 


I3S7 13.83 


41 


10.42 


10.67 


10.92 


II. 17 


II .42 


11.68 


11-93 


12.18 


12.43 


12.68 


12.93 '318 


13-44 


13-691I3-9S 


4.2 


10. 54 


10.79 


1 1 .04 


11 . 29 


11.54 


11.80 


I 2 .05 


12.30 


12.55 


12.80 


13.05 13-31 


13-56 


13-82 14.07 


4-3 


10.66 


10.91 


1 1 . 16 


II .41 


II .66 


II .92 


12.17 


12.42 


12.67 


12.92 


13.18 13-43 


13-68 


1 3 . 94 


14.19 


4-4 


10.78 


11.03 


11.28 


11-53 


11.78 


12.04 


12. 29 


12.54 


12.79 


13.04 


13.30 13-55 


13-80 


14.06 


14.31 


4-5 


10.90 


II. IS 


II .40 


II -65 


11.90 


12.16 


12.41 


12.66 


12.91 


13.16 


13.42 13-67 


13.92 


14.18 


14.43 


4.6 


II .02 


11.27 


11.52 


11.78 


12.03 


12.28 


12.53 


12.78 


13.03 


13.28 


13.54 13-79 


14-04 


14-30 


14.55 


4-7 


1 1 . 14 


II .40 


11.65 


II .90 


12.15 


I 2 .40 


12.65 


12.90 


13.15 


13-40 


13.66 13.91 


14. I () 


14-42 


14.67 


4.8 


II . 27 


11.52 


11.77 


12.02 


12. 27 


12.52 


12.77 


13.02 


13.27 


13.52 


13.78 14.03 


14.28 


14.54 


14-79 


4-9 


11-39 


II .64 


11.89 


12.14 


12.39 


12.64 


12.89 


13.14 


13.39 


13-64 


13.90 14-15 


14.40 


14.66 


14.91 


S-o 


II. 51 


II . 76 


12.01 


12. 26 


12.51 


12.76 


13.01 


13.26 


13-51 


13-76 


14.02 14.27 


14-52 


14-78 


IS. 03 


S-i 


11.63 


11.88 


12.13 


12.38 


12.63 


12.88 


13.13 


13.38 


13-63 


13.89 


I4.14>4.39 


14.64 


14-90 


15.15 


S-2 


11-75 


12.00 


12.25 


12.50 


12.75 


13-00 


13.25 


13-S0 


13-75 


14.01 


14.26 14.51 


14. 76 15 .02 


15.27 


S-3 


11.87 


12.12 


12.37 


12.62 


12.87 


13- 12 


13.37 


13-62 


13-87 


1413 


14. 38114. 63 


14.88 15.14 


15.39 


S-4 


11.99 


I 2 . 24 


12.49 


12.74 


12.99 


13-24 


13.49 


13-71 


14.00 


14-25 


14.50:14.76 


IS. 01 15.26 


15.51 


S-S 


12. II 


12.36 


12.61 


12.86 


13-11 


13.36 


13.61 


13.86 


14.12 


14-37 


14.62,14.88 


15.13 15.38 


15.63 


5-6 


12.23 


12.48 


12.73 


12.98 


13-23 


13.48 


13-73 


13-99 


14.24 


14-49 


14.75 15.00 


15.25 


15-50 


15.7s 


S.7 


12.35 


12.60 


12. 8s 


13. to 


13-35 


13-60 


13-85 


14. II 


14.36 


14-61 


14.87 15.12 


15-37 


15.62 


15.87 


5-8 


12.47 


12.72 


12.97 


13-22 


13-47 


13-72 


13-97 


14.22 


14-48 


14.74 


I4.99'l5.24 


15-49 


15. 74 


IS. 99 


5-9 


12.59 


12.84 


13.09 


13.34 


13-59 


13.84 


14. 10 


14.35 


14.60 


14.86 


IS. II 15.36 


15.61 


15.86 


16. 13 


6.0 


12.71 


12.96 


13-21 


13.46 


13.71 


13-96 


14.22 


14.47 


14.72 


14.98 


15.23 15.48 

1 


15.73 


15.98 


16. 24 



♦The lactometer reading is expressed in whole numbers tor c<jnvenience. The true specific gravity 
corresponding to a given lactometer reading is obtained by writing i.o before the lactometer reading. 
Thus, 1.026 is the specific gravity corresponding to lactometer reading 26, etc. 

t An. Rep. Mass. State Board of Health, 1901. p. 445. (Analyst's Reprint, p. 25.) 



MILK. J-- 

the acidity of "sweet" milk is due partly to the presence of acid phos- 
phates and partly to dissolved carbonic acid in the milk, and not to lactic 
acid, which is probably absent, a better plan is to express the acidity in 
terms of the number of cubic centimeters of tenth-normal alkali necessary 
to neutralize a given quantity of the milk, either 25 or 50 cc, using phenol- 
phthalein as an indicator. 

If it is desired to calculate the acidity in terms of lactic acid, multiply 
the number of cubic centimeters of tenth-normal alkali used by 0.897, ^-nd 
divide by the number of cubic centimeters of milk titrated, the result 
being the percentage of lactic acid. 

Detection of Boiled Uilk.—Slorch's Method."^— Shake 5 cc. of the 
milk in a test-tube with one drop of a 2 9c solution of hydrogen peroxide 
and two drops oi 3. 2% solution of paraphenylenediamin. If the milk 
has not been heated beyond 80'^C., a dark violet color appears at once, 
but if it has been pasteurized or boiled, no color appears. Siegfeld and 
Samson t find that addition of two drops of formalin (1:1) to each 100 
cc. of milk previous to boiling causes it to react similar to raw milk. 

MODIFIED MILK. 

A comparison of the composition of cow's milk and human milk, as 
in the following table by Dr. Emmett Holt,J shows verj' marked differ- 
ences. 

Woman's Milk, Cows Milk, 

Average. Average. 

Fat 4.00 3.50 

Sugar ,....,. 7.00 4-30 

Proteins ,...„... 1.50 4.00 

Ash , 0.20 0.70 

Water 87 . 30 ^7 - 5° 

The per cent of fat in the two kinds of milk is nearly the same. There 
is, however, too little sugar and an excess of proteins and ash in the milk 
of the cow, assuming human milk as the ideal infant food, so that in 
basing a diet for infants on the basis of human mUk considerable modi- 
fication is necessar}'. Moreover, aside from the actual variation in the 
amount of ingredients, there are certain inherent differences in the 
character of the same ingredient, as found in the milk of the cow and in 

* Copenhagen Expt. Sta., 40th Rep. t Molk. Ztg., 21, 1907, p. 103. 

X "Infancy and Childhood." 



156 



FOOD ANALYSIS AND INSPECTION. 



human milk. The proteins of cow's milk are, for instance, found to be 
much more difficult of digestion than those of woman's milk, and the 
same is probably true of the fat. Aside from the mere statement of a 
few of these differences, it is obviously beyond the scope of this work to 
discuss this phase of the subject in detail, reference being made, how- 
ever, to such books as Dr. T. M. Rotch's "Pediatrics," and "Infancy 
and Childhood" by Dr. Emmett Holt, for full particulars. So great 
has been the demand by physicians for "modified milk" for infant 
feeding, that laboratories for this exclusive purpose have been established 
in many of the larger cities, in which not only is milk prepared in 
accordance with certain fixed formulae supposed to be adapted to average 
infants of varying age, but milk of any desired composition is prepared, 
in accordance with special prescriptions of physicians to apply to indi- 
vidual cases. 

Methods and Ingredients. — The proteins and the ash in cow's milk 
are much higher than in human milk, and both are brought to the proper 
degree of reduction by diluting the milk with water. Milk sugar is 
increased by the addition of lactose, and the fat is increased or diminished 
by addition of cream or by skimming. 

The dilution of cow's milk with a measured amount of water shows 
the following results on the proteins and ash: 





Cow's Milk. 


Diluted 
Once. 


Diluted 
Twice. 


Diluted 
Three Times. 


Diluted 
Four Times. 


Proteins 


Per cent. 
4.0c 
0.70 


Per cent. 
2.00 

0-35 


Per cent. 
1-33 

0.23 


Per cent. 
1 .00 
0.18 


Per cent. 
0.80 


Ash 


0.14 







The ingredients commonly employed for modifying milk are (i) cream, 
containing 16% of fat, (2) centrifugally skimmed milk, otherwise known 
as "separator milk" from which the fat has been removed, (3) milk 
sugar, or a standard solution of milk sugar of, say, 20% strength, and 
(4) lime water. Unusual care should be taken in the selection of the 
milk supply to insure cleanness, purity, and freshness, as well as in the 
care of utensils, etc., used in the laboratory, which should in all cases 
be scrupulously clean. Samples prepared in accordance with a given 
formula or formula; are pasteurized in separate bottles, or, if desired, 
sterilized, and after stoppering with cotton are kept on ice. 

ForniulcB. — It is obviously impossible to establish formulae univer- 
sally applicable even to healthy infants, but the following may be 
regarded as typical formula;, representing the composition of modified 
milk to suit the needs of an average growing infant during its first year: 



MILK. 



^57 



Period. 


Fat. 


Proteins. 


Sugar. 


Third to fourteenth day 

Second to sixth week 


Per cent. 

2 

2-5 

3 

3-5 

4 

3-5 


Per cent. 
0.6 

o.S 
I.o 

1-5 

2 
2-5 


Per cent. 
6 
6 
6 
7 
7 
3-5 


Sixth to eleventh week 

Eleventh week to fifth month. . 

Fifth to ninth month 

Ninth to twelfth month 



Milk according to the above formulae can 
be ven,' simply prepared by the aid of a spe- 
cially made graduate known as the "Materna" 
and shown in Fig. 50. 

PREPARED MILK FOODS. 

Milk Powder. — There arc numerous brands 
of desiccated milk or milk powder on the 
market, sold in bulk and by the can, and largely 
used by bakers and manufacturers of milk 
chocolate. Many of these, purporting to con- 
tain all the ingredients of milk excepting water, 
have been found by the author to be pulverized 
dried skimmed milk. The following are analyses 
of whole milk, half-skim milk, and skim milk 
powders : 

Whole Milk, 
Powder.* 

Moisture 3.62 

Fat 26.75 

Proteins (NX 6. 25) 32.06 

Milk sugar 3 1 - 9° 

Ash 5.67 




Fig. 50. — The "Materna" 
(Graduate for Modifying 
Milk. 



Half-skim Milk, 


Skim Milk, 


Powder.* 


Powder. t 


5-01 


8.16 


15.26 


1-73 


38-39 


33-84 


34-67 


49-35 


6.67 


6.87 



100.00 100.00 99-95 

The fat in the skim milk powder corresponds to about 0.16% fat 
in the original milk. 

Jensen | states that the casein of dried milk no longer has the power 

* C. Huyge, Rev. gen. du Lait, 3, 1904, p. 400. 

t Analysis by the author. 

X Molkerei Ztg., Berlin, 15, 1905, p. 565. 



158 FOOD INSPECTION AND ANALYSIS. 

of swelling when mixed with water. To obviate this difficulty, Hatmaker 
adds to the milk i to 3% of sodium bicarbonate, and Elkenberg 2% of 
cane-sugar. A Swiss milk powder examined by Jensen contained an 
excess of sodium and a low acidity, indicating the addition of an alkaline 
sodium salt. 

Artificial Albuminous Foods. — The albumin and casein of milk have 
furnished the basis of a variety of food preparations, some of which are 
intended for the use of invalids and people of weak digestion, and others, 
from their comj)actness, for travellers and campers. Among these foods 
are the following: 

Nutrose. — This is a caseinate of sodium formed by the action of the 
alkali upon dried casein. It is soluble in water. 

Eucasin is a caseinate of ammonium, a soluble powder somewhat 
similar to nutrose. 

Plasmon. — This is a yellowish powder, prepared by treatment with 
sodium bicarbonate of the curd precipitated from skimmed milk. The 
compound is kneaded in an atmosphere of carbon dioxide, and reduced 
to a soluble powder. 

The following analysis of plasmon was made by Woods and Merrill ; * 



Water. 


Proteids. 


Fat. 


Carbohydrates. 


Ash. • Fuel Value. 


8.5 


75-0 


0.2 


8.9 


7-4 


2044 



Sanose. — This is also a powder, containing 80% of pure casein and 
20% of albumose, obtained from the white of egg. The powder possesses 
a slight taste and an odor suggestive of milk. By briskly stirring the powder 
with water, an emulsion may be made much resembling milk, but on 
standing it soon breaks up. 

Sanatogen is a grayish-white, tasteless powder, containing 95% of 
casein and 5% sodium glycero-phosphate. When treated with cold 
water it swells, forming on heating a milk-like emulsion. 

Koumis is a stimulating beverage, prepared by allowing milk to undergo 
alcohohc, lactic, and proteolytic fermentations. The original koumis 
was made by the Tartar tribes of Asia from mare's milk, which contains 
more lactose than cow's milk, and apparently lends itself more readily 
to fermentation. Only a limited amount of koumis is now made from 
mare's milk, the milk chiefly used for this preparation being that of the 
cow, treated with yeast and sometimes added sugar. Koumis is a 
beverage much more commonly used in Europe than in America. 

* Maine E,\p. Station, Bulletin 178, p. loi. 



MILK. 



IS9 



The following analyses were made by Vieth:* 



Mare's milk 92.07 

Cow's milk 90-57 

Skimmed milk 92-52 



Water. 



Alco- 
hol. 



Fat. 



^ . Albu- , Albu- 
Uasein. _,;_ min- 



2.98 
1.04 
0-57 



1.30 0.83 
1.38 1.88 
0-33 2.03 



0.24 
0.20 
0.07 



0.77 
0.77 
0.63 



Lactic 
Acid. 



1.27 
1.40 
0.56 



Sugar. 



0.23 
2.18 
2-45 



Ash. 



0-35 
0.58 
0.84 



Kephir. — This is a fermented milk product similar to koumis, excepting 
that the fermentation is induced by a fungus known as kephir grains. 
The proteolytic fermentation is less pronounced in kephir than in koumis. 
Konig gives the following table as the mean of twenty-eight analyses: 



Water. : ^^^'^ Casein. ^'^- Albu- 
gen. nun. 



Hemi- 
albumin. 



Pep- 
tone. 



Fat. 



Lac- 
tose. 



Lactic 
Acid. 



Alco- 
hol. 



I Ash. 



91.21 3.49 



2-53 I 0-36 ' 0.2I I 0.21 I 0.039 1.44 



2.41 



•75 0-68 



ADULTERATION OF MILK. 

Systems of Milk Inspection. — A typical method of general food inspec- 
tion has already Vjeen outhned (see pp. 6 and 8), which may easily be modi- 
fied to include the inspection of milk in connection with other foods, or to 
provide for a system of milk inspection exclusively. In the examination 
of such a perishable food as milk, it has not been found practicable for 
the analyst to reserve for the benefit of the defendant a sealed sample, 
as in the case of other foods, but experience has shown it had best be made 
the duty of the collector or inspector to give a sealed sample of milk to 
the dealer, when the latter requests it at the time of taking the sample. 
For this purpose the collector is provided with small bottles and sealing 
pharaphemaha, in addition to the tagged sample bottles or cans in which 
he collects the milk. The collector should use the same precautions 
for obtaining a perfectly fair representative sample as does the chemist 
in making the analysis, i.e., he should carefully pour the milk from the 
original container into an empty can or vessel and back again, before 
taking his sample. 

Each sample is properly numbered by the collector in presence of the 
dealer, and the data as to the taking of the sample entered at once under 
the proper number in the collector's book. If a sealed sample is given, 



* Richmond Dairy Chemistry, p. 241 et seq. 



l60 FOOD INSPECTION AND ANALYSIS. 

• 
it should bear the same number as the sample resen-ed for analysis, and 
a receipt should invariably be required from the dealer, as e\'idence that 
his request for a sealed sample has been compUed with. 

Milk Standards Fixed by Law. — In localities where a systematic form 
of milk inspection prevails, there is usually in force a statute fixing the 
legal standard for the total solids, and in many cases for the fat or for 
the solids exclusive of fat. In some states the statute is so drawn that 
any deviation from the legal standard constitutes an adulteration in the 
eye of the law, and hence the oflFender, who has such milk in his possession 
with intent to sell, is liable to the same fine as if he actually added water 
or a foreign substance to the milk. 

In other states a distinction is made by the statute between milk that 
is simply below the legal standard of total solids, and milk containing 
actually added ingredients (water or otherwise), a much hghter fine being 
imposed for the former than for the latter offense. Where such a dis- 
tinction prevails, it often becomes incumbent upon the analyst to show 
to the satisfaction of the court, in case of milk low in sohds, whether or 
not the milk has been fraudulently watered after being dra^^Ti from the 
cow, it being well understood that cows may give milk below the standard. 
Pure milk that is low in sohds may owe its deficienc}- either to poor 
feeding, or to an inherent tendency on the part of the cow to give milk 
always of poor quahty. Thus the Holstein cow, more than any other 
breed, is open to the charge of sometimes giving milk below the standard.* 
That the Holstein cow is a favorite with the producer is by no means 
strange, from the fact that no other breed can with moderate feeding 
be made to give so large a quantity of milk. 

Wherever there is a statute fixing the standard for milk, it commonly 
provides also that the addition of any foreign substance whatsoever con- 
stitutes an adulteration. 

U. S. Standards.f— 5/a«^ar(/ milk is the fresh, clean, lacteal secre- 
tion obtained by the complete milking of one or more perfectly healthy 

* This statement should not be taken as condemning the Holstein, for it is true that cows 
of this breed often give milk, far above the standard. A large number of samples of mill; 
of known purity from Holsteins analyzed by the wTiter have been found to be of excellent 
qualitv. It is a curious fact that among the samples of known purity analyzed by the Massa- 
chusetts Board of Health, both the lowest and highest total solids on record came from a 
Holstein cow; the lowest recorded total solids in a 'known purity" milk being 9.96 per 
cent, (seventh annual report of Massachusetts State Board of Health, Lunacy, and Charity, 
p. 160), and the highest being 17.06 per cent, (twenty-second annual report of the Massa- 
chusetts State Board of Health, p. 405). 

tV. S. Dept. of .\gric., Off. of Sec, Circ. 19. 



MILK. i6l 

COWS, properly fed and kept, excluding that obtained within fifteen days 
before and ten days after calving, and contains not less than 8,5% of 
solids not fat, nor less than 3.25% of milk-fat. 

Standard Skim-milk is skim-milk containing not less than 9.25% of 
milk soHds. 

Forms of Adulteration.— Milk is ordinarily adulterated (i) by 
watering, (2) by skimming, (3) by both watering and skimming, and 
(4) by the addition of one or more foreign ingredients. 

Watering and Skimming. — The fact that milk is found below the 
standard of total solids, while more often due to an excess of water, may 
also be due to a deficiency in fat. In one case the milk is commonly 
termed watered, and in the other skimmed, using the terms broadly and 
not necessarily meaning actual and fraudulent tampering with the milk. 
In a third case, and almost invariably fraudulently, both watering and 
skimming may be found to have been practiced on the same sample. 
The analyst judges which of these causes have produced a milk low in 
solids, by a careful study of the relation between the percentages of total 
sohds, fat, and solids not fat. 

If both the total solids and solids not fat are abnormally low, and 
the proportion of fat to solids not fat about the same as, or higher than, 
in a normal milk, it is generally safe to assume that the sample has been 
watered; if both the total sohds and the fat are well below the standard, 
and the solids not fat nearly normal, then the milk has undoubtedly been 
skimmed; if, in the third place, the total sohds and the soHds not fat are 
proportionally reduced below the standard, while the ratio of fat to solids 
not fat is abnorfnally small, it is safe to adjudge the milk to be low by 
reason of both skimming and watering. 

Milk of Known Purity. — It is difficult to place the minimum figure 
for total solids, below which a milk sample may safely be pronounced 
by the analyst as fraudulently w'atered after having been drawTi from 
the cow. Nearly nine hundred sr.mples of milk of known purity from 
various breeds of cow, milked in the presence of an inspector, have been 
analyzed in the Department of Food and Drug Inspection of the Massa- 
chusetts State Board of Health, extending over a period of fifteen years, 
and among these are many samples from Holstein cows. It is extremely 
rare that any of these known purity samples have been found with total 
solids as low as 11%, though there are instances where total solids have 
run as low as 10%. 



1 62 FOOD INSPECTION AND ANALYSIS. 

It is safe to assume that in the few cases on record showing less than 
10.75% of total solids, either there was something decidedly abnormal 
about the health of the cow, or, through some accident, the cow was only 
partially milked, it being a well-known fact tnat the last fraction of the 
milking includes the larger percentage of fat. (See page 128.) 

It is therefore nearly always safe to condemn a milk standing below 
10,75 ^s fraudulently watered, if at the same time it has a proportionately 
high per cent of fat. 

The average total solids of 800 samples of milk of known purity analyzed 
by the Massachusetts Board up to and including the year 1890 amounted 
to about i3i%. 

It is rare indeed to find a herd of ten or more well-fed cows of mixed 
breeds in which the average milk of the herd falls below 125% of 
solids. 

The milk of forty-seven Holstein cows, examined in 1885, was 
found to contain an average of 12.51% of total solids, while the 
milk of eleven Jerseys examined in the same year averaged 14.02% 
of solids. These examples represent the two extremes commonly met 
with. 

Variation in Standard. — In Massachusetts the law fixes a different 
standard for total soHds in milk during the summer, or pasture-fed season, 
from that in force during the winter, or stall-fed period. From April 
to September inclusive the legal standard is 12% of total solids, of which 
9% are solids not fat, and from October to March inclusive it is 13%, of 
which 9.3% are solids not fat. Bearing on the question of difference in 
normal quality of milk during the two periods, averages were taken of the 
milks collected by the corps of inspectors of the Massachusetts Board of 
Health during a month in each period, December and June being selected 
as most typical, and during these months all the samples were analyzed 
both for total solids and fat. The samples were taken from stores, milkmen, 
and producers, and represented as nearly as possible the milk as actually 
sold to the consumers. In making the averages, all samples of skimmed 
milk, as well as all samples standing above 17% of total solids, or under 
iO'75%> were deducted. The results are summarized as follows: 



MILK. 



163 



QUALITY OF MILK SOLD IN MASSACHUSETTS CITIES AND TOWNS IN 

WINTER AND SUMMER. 





December. 




Number 

of 
Samples. 


Total Solids. 


Fat. 


Solids 
not Fat. 
Average 
Per Cent. 




Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Cities 

Towns 

Simimary 


403 

99 

502 


16.86 
15.48 
16.86 


10.88 
12.02 
10.88 


13.21 
13-44 
13-32 


8.50 
6.65 
8.50 


2.40 

3-5° 
2.40 


4-37 
4-48 
4.42 


8-74 
8.96 
8.85 



Cities . . . , 
Towns . . . 

Summary . 



Jtme. 



Number 

of 
Samples. 



3" 
76 

387 



Total Solids. 



Highest Lowest 
Per Cent. Per Cent. 



16.90 

IS-71 
16.90 



IO-75 
10.99 

10-75 



Average 



Fat. 



Highest 



Per Cent, i Per Cent. 



12.67 
12.63 
12.65 



8.80 
7.10 
8.80 



Lowest 
Per Cent. 



2.10 
3.00 
2.10 



Average 
Per Cent. 



4-03 
4.09 
4.06 



Solids 
not Fat. 
Average 
Per Cent. 



8-54 
8-54- 
8-54 



It is interesting to note that the average for total solids of the 88g 
samples examined for both months stands at just 13%, of which 4.24% is 
fat and 8.76 is solids not fat. 

Rapid Approximate Methods of Determining the Quality of Milk. — 
The Lactometer. — A rough idea of the quality of milk can be gained by the 
use of the lactometer (page 131), but, in view of the fact that a low specific 
gravity may be the result either of a watered milk or of a milk high in fat, 
good judgment is necessar}" in connection with its use. A milk of good 
standard quality should have a specific gravity between the limits of 
1.027 and 1-033. -^ watered milk would run below the former and a 
skimmed milk above the latter figure, though a milk unusually rich in fat 
would also run low. It should easily be apparent from the taste and appear- 
ance of the milk, whether a low specific gravity is due to watering or 
unusual richness in fat. The fact should also be recognized, that a milk 
sample may be far below the standard, and still show a specific gravity 
within the limits of pure milk, by skillfully subjecting the milk to both 
skimming and watering. 

The Lactoscope. — Feser's lactoscope (Fig. 51) gives an approximation to 
the amount of fat in milk, and its use, especially in connection with the 
lactometer, is of some value. This instrument consists of a graduated glass 
barrel, a, into the bottom of which is accurately fitted the stopper, bearing 



l64 FOOD INSPECTION ^ND ANALYSIS. 

a white glass cylinder, having black lines thereon. Four cc. of milk are 
introduced into the barrel by means of a pipette, c, and water is added 
with thorough mixing till the translucence of the mixture Ls sufficient to 
allow the black lines to be perceptible through it. The height of the level 
of milk and water in the Ijarrel a is then read off, the number indicating 
roughly the percentage of fat in the sample. 

As in the case of the lactometer, the purity of a milk sample cannot 
be positively established by the lactoscope alone. For instance, a watered 
milk abnormally high in fat would often be found to read within the limits 
of pure milk, when as a matter of fact its total solids would be below stand- 
ard. By a careful comparison of the readings of both the lactoscope and 
lactometer, however, it is rare that a skimmed or watered sample could 
escape detection. 

Thus, if the specific gravity by the lactometer is well within the limits 
of pure milk, and the fat, as shown by the lactoscope, is above 3^ per 
cent., the sample may be safely passed as pure, or as conforming to the 
standard. 

A normal lactometer reading in connection with an abnormally low 
lactoscope reading shows both watering and skimming, and with an 
abnormally high lactoscope reading shows a milk high in fat, or a cream. 
With the lactoscope reading below three, and a low lactometer reading, 
watering is indicated. A lactometer reading above thirty-three, and a 
low lactoscope reading, indicate skimming. 

Ilceren's Pioscope. — This instrument consists of a hard-rubber disk, 
having in the center a shallow receptacle, the circular rim of which is raised 
above the level of the disk. Into this receptacle are introduced a few 
drops of the milk to be tested, and a circular cover-glass containing a 
number of variously tinted segments is placed over the receptacle, which 
spreads the milk out into a thin layer, and causes it to assume a tint against 
the black background that can be matched with one of the colors on the 
glass, the various tints indicating milks of various grades from the very 
poorest to rich cream. This test is at best a very rough one. 

Examination of the Milk S^rnm.— Detection of Added Water.— 
This may often be detected by determining the specific gravity or the 
degree of refraction of the milk serum, since it has been found that under 
fixed conditions the composition of the milk serum, or clear " whey," 
is more constant than that of the milk itself. Hence any considerable 
amount of watering is manifest from the physical constants of the serum. 
In using this method the analyst should carefully work out his own 



MILK. 



i6s 



standards for comparison, by personal experiment on milk of known 
composition to which varying amounts of water have been added, using 




100 



80 



'A A 



Fig. 51.— Feser's Lactoscope. 

the same conditions for obtaining the serum in all cases. Woodman's 
method* is as follows: To 100 cc. of the milk at a temperature of about 
20° C. are added 2 c c. of 25% acetic acid, specific gravity i.o35o> ^" ^ 

* Jour. Am. Chem. Soc, 21, 1899, p. 503- 



1 66 



l-OOl) INSPHCriON AND AN.'II.YSIS. 



beaker, and the Ix-aker, covered with a watch-glass, is heated in a water- 
bath for 20 minutes at a temperature of 70° C. After this the beaker is 
placed in ice water for 10 minutes and the .solution fihcred. 

Specific Gravily. — The specific gravity of the clear filtrate, obtained 
by the method described above, is taken at 15° C. with the We.stphal 
balance. 

Immersion Refractomeler Reading. — The instrument u.scd is the Zeiss 
immersion or dipj)ing refractometer described on ])ages iii to 121. The 
serum, ])rej)ared as directed in a preceding paragraj)h, is examined in 
one of the small beakers accompanying the ai)|)aratus at a temjjerature 
of 20° C. 

Constants of the Serum. — The tliree tables which follow show the 
variation of specific gravity and immersion refractometer reading on milk 
of different composition. 

Analyses of whole milk submitted by the author to varying degrees 
of watering, up to 50% of added water, are given in the following table: 



CONSTANTS OF MILK AND MILK SERUM. A WHOLE MILK 
SYSTEMATICALLY WATERED. 



Determinations on Milk. 


On Milk Serum. 


Added 

Water, 

Per Cent. 


Total 

Solids. 

Per Cent. 


Water, 
Per Cent. 


Fat. 
Per Cent. 


Solids 
not Fat, 
Per Cent. 


Ash, 
Per Cent. 


Specific 
Gravity 
at 1 5° C. 


Specific 
Gravity 
at is° C. 


Immersion 
Refrac- 
tometer 
Reading 
at 20° C. 



10 
20 
30 
40 

50 


12.65 

^^■33 
10. 10 

8-95 
7.67 

6.43 


87-35 
88.67 
89.90 
91.05 
92-33 
93-57 


4.00 
3-5° 
3.10 
2.80 
2.40 
2.00 


8.6s 

7-83 
7.00 
6.15 
5-27 
4-43 


0.65 
0.60 

0-53 
0.48 
0.40 
0.38 


I -0315 
1.0278 
1.0252 
1. 02 1 1 
I .0192 
1.0154 


I .0287 
I .0260 
1.0230 
I . 0200 
I .0167 
I .0140 


42.40 

39-75 
36.90 
34.10 
31.10 
28.45 



The first table on |). 167 shows a centrifugally .skimmed milk, .sy.stemat- 
ically watered up to 50 A' of added water, as in the preceding table. It 
will be ob.served that both the si)ecific gravity and immersion refractom- 
eter readings of the serum of the whole milk, agree very closely with 
those of the skimmed milk in ca.ses having a corresponding amount of 
added water. 

The second table on p. 167 shows analyses of milk selected from a 
wide range of samj)les regularly collected and examined in the routine 
of food inspection by the Massachusetts State Board of Health, 



MILK. 



167 



CON'ST.\XTS OF MILK AND MILK SERUM. A SKIMMED MILK 
SYSTEMATICALLY WATERED. 





Deteminations on ililk. 


On Miik Serum. 


1 
Added 1 


Total 


Water, 


Pat 


Solids 


Ash. 


1 
^ . ., i ^ - Immersion 
Specific ! Specific Refrac- 


Water. ' 


SoUds, 


Per Cent. Per Cerit 


not 


rat. 


Per Cjmt 


Gra'.-'-ty | Gravity 1 tr/rr.eUiT 


Percent. : Per Cent. 1 " 


Per Cent. 1 1 at i ;' 


^. at I s C. j Reading 
; at 20'' C. 


i 


9.05 90.95 0.03 , 9 


02 0.64 


1.0350 1.0296 , 42.85 


10 1 


8.14 91-85 j 0.03 1 8 


II 


0.60 


1. 03 1 


7 1.0260 , 39-60 


20 1 


7-27 


92.73 ; 0-02 


7 


25 


0.56 


1.0278 1.0230 


36-85 


30 1 


6-41 


93-59 0.02 


6 


39 


0.48 


1.0247 1.0200 


34 00 


40 


5-50 


94.50 O.OI 


5 


49 


0.44 


1.0209 I. 0170 


31.20 


5"^ 


4.61 


95.39 1 O.OI 


4 


60 


0-39 


I. 0172 I. 0140 


28.50 


CONSTANTS OF i 


IILK .\ND MILK 
Detenninations on MiiV. 


SERUM. LABO 


R.\TORY S.\MPLES 




] 


On Milk Serum. 


Total Solids, 


Water. | Pat, 


SoKds 
not Pat, 


Ash, 


Specific 
Gra-zity 
at 15' C. 


Specific InMnersion 
Gra-/ity ' Ketractom- 
atis'C. ,««• Read- 


Per Ceat. 


Percent. Per Cent. 


Per Cent. 


Percent. 




1 








ing at 20' C 


16.45 
i5-9<' 


83-55 
84.10 


8.20 


8.2c 




1 . 05 c c 


1 . 02 7 J. <lo r 


7.00 


8. 


90 


0.69 




— j>j 
.0277 


I . 0285 ' 42 


00 


14-37 


85.63 


5-50 


8. 


88 


0.58 




0282 


1.0280 I 42 


40 


14-17 


85.83 


4-85 


9 


32 


0.62 




0313 


I. 0281 1 44 


20 


14.04 


85.96 


4-95 


9- 


09 


0.60 




0303 


1.0274 


42 


70 


13.80 


86.20 


5-00 


8 


80 


0.65 




0302 


1.0289 


42 


75 


13-59 


86.41 


4-30 


9 


29 


0.64 




0321 


1.0285 


44 


50 


13-39 


86.61 


4.40 


8. 


99 


0.50 




0324 


I . 0285 


43 


70 


13.28 


86.72 


4.40 


8. 


88 


0.60 




0299 


1.0289 


42 


65 


13.12 


86-88 


4.00 


9- 


12 


0-59 




0317 


1 . 0280 i 43 


75 


13.00 


87.00 1 4.30 


8. 


70 


0.56 




0310 


1.0266 


42 


60 


12.90 


87.10 3.85 


9 


05 


0.61 




0318 


1.0289 


43 


40 


12-80 


87.20 4.30 


8- 


50 


0.46 




0304 


1.0277 


42 


70 


12.70 


87.30 1 3-80 


8. 


90 


0-53 




0314 


I- 0280 


43 


10 


12-63 


87-37 ■ 3-50 


9- 


13 


0.65 1 I 


0323 


1.0277 


43 


65 


12.62 


87.38 4.10 


8. 


52 


0.52 I 


0298 


1-0272 


42 


40 


12.57 


87-43 1 3-70 


8. 


87 


0.68 I 


0317 


1.0278 


43 


45 


12.47 


87.53 1 3.60 


8- 


87 


0.65 




0303 


I . 0282 


43 


15 


12.36 


87.64 3.20 


9- 


16 


0-55 




0327 


I . 0282 


43 


25 


12. 30 


87.70 , 3.20 


9- 


10 


0.62 




0327 


1.0283 


44 


00 


12- 16 


87.84 ; 4.35 


7- 


81 


0.49 




0275 


1.0265 


41 


10 


12.00 


88.00 1 3.40 


8. 


60 


0.62 




0275 


1.0280 


41 


75 


11-86 


88.14 1 3-60 


8. 


26 


0.49 




0306 


1.0266 


42 


40 


11-67 


88.33 ! 3-95 


7- 


77 


0.48 




0265 


I . 0240 


39 


30 


ir.6o 


88.40 2.75 


8. 


85 


0.65 




0320 


I . 0282 


43 


55 


11-50 


88.50 . 3.45 


8- 


05 


0.51 




0290 


1.0269 


41 


40 


11.40 


88.60 f 3.10 


8- 


30 


0.60 




0297 


1.0278 


42 


00 


11.25 


88.75 \ 2. So 


8- 


45 


0.58 




0280 


1.0274 


40 


90 


11.07 


88.93 1 300 


8. 


07 


0.62 




0290 


1.0270 


40 


75 


10.69 
ro-25 


89.31 { 2.95 
89.75 ' 3^^ 


7- 
6- 


74 
95 






0288 


1.0262 


39 
36 


85 
40 


, , 

0.5s 




0230 


1.0223 


8-3-t 


91 .66 2 .20 


6.14 


0.33 


1.0224 


1 . 0207 


34.70 



l6o FOOD INSPECTION AND ANALYSIS. 

A comparison of the immersion refractometer readings of the serum 
of milk of varying quality shows at once that the refraction of the serum 
is a general index to watering, A reading below 40 with the above 
conditions carefully observed would be suspicious of added water, though 
39 might more safely be placed as a limit, below which milk could be 
declared fraudulently watered. The analyst need not hesitate in testify- 
ing to the presence of added water, when in addition to giving a refraction 
reading lower than 39 under the above conditions, the solids not fat stand 
below 7.3 f^,. 

The tables on page 169 are of interest, as they show, in summarized 
form, refractometric and analytical results from a large number of milk 
samples from three widely separated localities, namely, Massachusetts, 
New Jersey, and Great Britain : * 

Nitrates. — The presence of nitrates in milk furnishes strong evidence 
of watering. Pure milk, free from contamination with stable filth, 
contains no nitrates; well water, however, often contains a sufficient 
amount to enable the detection of a 10% admixture in milk. 

Richmond f employs for this test a solution of diphenylamin in con- 
centrated sulphuric acid (o.i gram to 100 cc). One cc. of the mixture 
is placed in a small porcelain crucible, and a drop of the milk serum is 
run down the side and allowed to flow over the surface. If a blue color 
appears within 10 minutes, the presence of nitrates is indicated. A 
brownish color always forms on standing for a longer time, whether or 
not nitrates are present. 

Patrick finds that the delicacy of the test is greatly increased by 
adding to the reagent a small amount of sodium chloride some time 
before using. 

Systematic Examination of Milk for Adulteration.— If a 
large number of samples of milk have to be examined daily for adul- 
teration, it may be an advantage to submit all to a preliminary test with 
the lactoscope and lactometer, excluding from further analysis, as above 
the standard, such samples as pass certain prescribed limits which experi- 
ence has proved these tests to be capable of showing to an experienced 
observer, and submitting the remainder to a chemical analysis. In 
using such an instrument as the lactoscope for this purpose, the individual 
element is a most important consideration, and the use of this instrument 

* An. Rep. Mass. State Board of Health, 1906, p. 3S4. 
t .Analyst, 18, 1893, p. 272. 



MILK. 



169 



JO uopoBJja'5j 



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';b^ jou spijog 



■;u3o jaj 'jbjI 



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J3d 'spiios ib;ox 



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-lUBg JO jaqiun^Nj 



O 00 C^0O O t^ a- t^oo r- 



\n o Trmro'^r»"^t^ f* f^ 



vo ^^t'd-w^^ONNwi-iOO 



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'IB^ jou 'spiios 



•}U90 jaj 'IBJ 



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J3<J 'SpilOg IBJOX 



•sajd 
-uiBg JO jaquinfj 



•3^°^ }BUirU3g 

JO uoijOBJja'a 



•juao J3(j 
•IBJ ?ou spHOg 



■;U33 J3d '%V^ 






sajd 
-uiBg JO jaquinjvi 



Com" 

O -^tj ^ 

'■3 S£^ c 

n! c o S 
ICT3 

•— i-i"t: u 

^ o is «> 



\0 »0 t-- ro N 



N O 



CMiO 000 00 



00 00 



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o o 

o o 



rt rf r^ ro 



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ro P< M M M O O 



S •/) S '-^ s ^ a =^ s >« s =« 

fcc| tC^ bc| tc| tsc| bD| 

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i 



170 FOOD INSTECTION AND ANALYSIS. 

in the milk laboratory should be limited only to a skillful operator, 
accustomed to interpret its results. 

The method used in the writer's laboratory has been to submit all 
samples to the regular test for solids, and such samples as fall below 
the legal standard for solids, are further examined for fat. 

Total Solids, Ash, and Fat. — It is presupposed that the analyst is 
equipped with a sufficient number of platinum dishes for the number 
of milk samples daily analyzed. It is a convenience to have these dishes 
numbered, and instead of weighing each dish, to have a system of num- 
bered counterweights (Fig. 52, .4) corresponding to the dishes. The 
counterweights in use by the author for this purpose are easily made 
from half-inch lead pipe, cut to the appropriate length and flattened. 
Each weight is then carefully adjusted to its appropriate dish, by trim- 
ming off the weight with a knife, or by adding bits of lead scraps, if 
necessary, by simi)ly prying open in the center, inserting the required 
amount of scrap, and then closing by a blow of the hammer, the weight 
being plainly numbered before final adjustment. A rack is provided 
by the side of the balance-case (Fig. 52) with slits for holding the weights 
in their appropriate places. Such a set of counterweights is not difficult 
to make, requires very little care to keep in adjustment, and is an 
immense labor-saving device. 

Details of Manipulation. — The following method of examining large 
numbers of milk samples is the one in use in the laborator}' of the Massa- 
chusetts State Board of Health and is given in some detail, as long exper- 
ience has proved it to be rapid, easy, and accurate. 

From 12 to 20 samples of milk are conveniently weighed out at a 
sitting, the unopened sample cans or bottles being contained in a tray 
at the left of the operator on a low stand, another low stand and tray 
being at his right hand for the cans, after removing the weighed portions, 
and a third tray on the table at the right of the balance for the platinum 
dishes with the weighed samples. The analyst enters the number of 
the platinum dish in his note-book, or on a card,* in Hne with the number 
of the milk sample, verifies the correctness of the counterweight, and 
weighs out exactly 5 grams of the milk with the aid of a pipette, after 
first having thoroughly mixed the sample. This operation is repeated 
with all the samples, the platinum dishes containing the weighed amounts 

* Specially ruled library cards, as shown on page 172, are useful for this purpose. 



MILK. 



171 



of each being placed in succession on the tray, which is finally carried to 
the water-bath and the dishes transferred thereto. The time required 
for weighing out 12 samples of milk in this maniK-r is about fifteen minutes. 
The water-bath is inclosed in a hood, and the sliding front is so arranged 
that it can be shut down and locked, so that if the analyst has to leave 




Fig. 52. — Set of Gjunterweights for Numbered Piatinum Dbhes, in a Convenient Rack- 

A. One of the Counterweights. 

B. Platinum Dishes. 

the laborator}' during the three hours required for the evaporation, he 
can swear in court that the samples could not be tampered v^ith during 
his absence (see page 21). 

When ready to make the second weighings for the total solids, c^ch 
dish is taken from contact ^sith the steam, and, while still hot, is wped 
'"• -with a soft towel, till twelve of the dishes are placed on the tray, 
ich is then taken to the balance. Experience has shown that with 
:nar\' rapidity in weighing, twelve of the residues may be thus deak 
v/.th at a time without the need of a desiccator, the gathering of mobture 
during that time being inappreciable, excepting in ven' damp weather, 
when a less ntunber of dishes shoidd be removed at a time from the bath- 
In making the second weighing, and employing the coimterReight as 



172 




FOOD 


INSPECTION AND ANALYSIS. 








Date.. 


Sl^U^SMCOH 


7 


/90V 






Inspector's 
Number. 


No. of 


WtT«MtdL/e. 
5" G ramx. 


Total 
Solids. 


No. of 
Botlle 


Fat. 


So\\.dt -not 
Tat 


'Rtma.rHS' 


. ZG^Z f 


1 


.6^6'g' 


JZ.9\ 










16^^ 


2 


hi>'3 


J3.0i> 










i6V6 


,? 


GOI 1 


IX.OZ 










lh^9 


V 


S'<fS6 


yy.96 


3 


3 Zif 


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XG6-0 


,r 


72.6? 


J^S'S 










2.66-^ 


6 


An^ 


^.36" 


"r 


Z.SO 


s-^s 




Z(^6^^ 


7 


.^223 


'J3.6S 










Z(,6'(> 


,f 


.6301 


JX.GO 










Z(y5-S 


9 


^9Z^ 


/3.9y 










2^i.O 


JO 


fyJSS 


12.Z1 










T^bbl 


// 


.^5-96- 


9.19 


S 


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9.0^ 




Xhb^ 


/^ 


^693 


9.39 


6 


(LS6' 


6.6*1 




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6i-30 


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Xi>(>2 


J^ 


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^293 


1Q..S9 










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7393 


1^.19 








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17 


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7.80 




Ik^O 


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. (,6-31 


J3.0G 











































































































































Specimen Card for Analy.st's Records of Milk Analyses. To he filed in a cabinet. 



MILK. 



173 



before, the exact net weight of the residue is at once ascertained and 
entered in the appropriate column in the note-book. IMultiplied by 
20 it gives at once the percentage of total solids. 

It is a great saving of time to weigh out exactly 5 grams as above 
described. The knack of quickly measuring out the exact amount is easily 
acquired with practice, the 5 -gram weight is the only one required for 
the operation with the counterweight of the dish, and the laborious figuring 
of percentage due to using a fraction above or below the 5 grams of milk 
is avoided. 

Such samples as are found to stand below the standard of total soHds 
are further examined for fat by the Babcock process (p. 136), entering 
the number of the fat bottle in the note-book in the appropriate column, 
and subsequently the percentage of fat. 

Ordinarily the specific gravity is not determined, excepting in some 
cases of badly watered milk, when, for purposes of a check, it is customary 
to take the specific gravity, and calculate the solids from the gravity and 
the fat by Babcock's formula (p. 153), or the Richmond shding scale, and 
compare the result with the figure directly determined. 

The ash is rarely weighed except in special cases. 

The dishes containing the drx residues are easily cleaned by first 
burning to an ash and cooling, after which they are treated successively 
with strong nitric acid, which is poured from one to another, the dishes 
being rinsed thoroughly with water and finally heated to redness. 

A convenient device for ashing a large number of residues for purposes 
of cleaning the platinum dishes and for final heating is the incinerator 
shown in Fig. 53, made of Russia iron. 



^2c>^ 




Fig. 53. — A Sheet-metal Incinerator, Specially Useful for Ashing Milk Residues. 



ADDED FOREIGN INGREDIENTS. 



Passing over such mythical and impossible adulterants as chalk, and 
the almost as rarely used substances calves' brains, starch, glycerin, 



174 FOOD INSPECTION AND AN/iLYSlS. 

sugar, etc., often discussed in manuals on milk, but with few authentic 
instances of their actual occurrence, the commonly found adulterants 
may be divided into two classes: coloring matters and preservatives. 

The coloring matters almost exclusi\ely used are annatto, azo-colors, 
and caramel. The preservatives commonly met with are formaldehyde, 
boric acid, borax, and sodium bicarbonate. Rarely salicylic and benzoic 
acids are found. 

Coloring Matters. — While it is more often true that an artificially 
colored milk is also found to be watered, the coloring being added to 
cover up evidence of the watering, it is not uncommon to find added 
coloring matter in milk above the standard.* 

About 95% of the milks found colored in Massachusetts show on 
analysis the fraudulent addition of water. 

Statistics of the Massachusetts State Board of Health show that out 
of 48,000 samples of milk collected throughout the state and analyzed 
during nine years (from 1894 to 1902 inclusive) 342 samples or 0.7% 
were found to contain foreign coloring matter. Of these samples, about 
67% contained annatto, approximately 30% were found with an azo- 
dye, and about 3% with caramel. 

Until comparatively recently annatto was employed almost exclu- 
sively for this purpose. Caramel is least desirable of all the above colors 
from the point of view of the milk-dealer, in that it is difficult to imitate 
with it the natural color of milk, by reason of the fact that the caramel 
color has too much of the brown and too little of the yellow in its com- 
position. Annatto, on the other hand, when judiciously used and with 
the right dilution, gives a very rich, creamy appearance to the milk, even 
when watered, which accounts for its popularity as a milk adulterant. 
Of late, however, the use of one or more of the azo-dyes has been on 
the increase, and so far as a close imitation of the cream color is con- 
cerned, these colors are quite as efficient as annatto. 

Appearance of Artificially Colored Milk. — The natural yellow color 
of milk confines itself largely to the cream. An artificial color, on the 
contrary, is dissipated through the whole body of the milk, so that when 
the cream has risen in a milk thus colored, the underlying layers, instead 
of showing the familiar bluish tint of skimmed milk, are still distinctly 
tinged below the layer of the fat, especially if any considerable quantity 
of the color has been used. This distinctive appearance is in itself often 

* In one instance an azo-dye was found by the writer in a milk that contained over 
17% of total solids. 



MILK. 175 

sufiBcient to direct the attention of the analyst to an artificially colored 
milk, in the coui^e of handling a large number of samples. 

Nature of Annatto. — Annatto, amatto, or annotto is a reddish-yellow 
coloring matter, derived from the pulp inclosing the seeds of the Bixa 
orellana, a shrub indigenous to South America and the West Indies. 

A solution of the coloring matter in weak alkah is the form usually 
employed in milk. 

Nature of "Anilin Orange." — Of the coal-tar colors employed for 
coloring milk, the azo-dyes are best adapted for this purpose and are 
most used. A few samples of these commercial "milk improvers" have 
fallen into the hands of the Department of Food and Drug Inspection 
of the Massachusetts Board of Health, and have proved, on examination, 
to be mixtures of two or more members of the diazo-compounds of anilin. 
A mixture of what is known to the trade as "'Orange G" and "Fast Yel- 
low" gives a color which is practically identical with one of these prep- 
arations, secured from a milk-dealer and formerly used by him. 

For purposes of prosecution or otherwise, it is obviously best in our 
present knowledge of the subject to adopt a generic name such as "a 
coal-tar dye"' or "anUin orange''* to designate this class of coloring 
matters in milk, rather than to particularize. 

Systematic Examination of Milk for Color. — The general scheme 
employed by the writer for the examination of milk samples suspected 
of being colored is as follows : j About 1 50 cc. of the milk are curdled by 
the aid of heat and acetic acid, preferably in a porcelain casserole over 
a Bunsen flame. By the aid of a stirring-rod. the curd can nearly always 
be gathered into one mass, which is much the easiest method of separa- 
tion, the whey being simply poured off. If, however, the curd is too 
finely divided in the whey, the separation is effected by straining through 
a sieve or colander. AH of the annatto, or of the coal-tar dye present 
in the mUk treated would be found in the curd, and part of the caramel. 
The curd, pressed free from adhering liquid, is picked apart, if necessar}*, 
and shaken with ether in a corked flask, in which it is allowed to soak 
for several hours, or until the fat has been extracted, and with it the 
annatto. If the milk is uncolored, or has been colored with annatto, 
on pouring off the ether the curd should be left perfectly white. If, on 

* The term " anilin orange" has been so commonlv applied during the last eight years 
to any color or mixture of colors of this class in complaints in the Massachusetts courts, as 
to have acquired a special meaning perfectly well understood. 

t Jour. Am. Chem. Soc., 22, 1900, p. 207. 



176 FOOD INSPECTION AND ANALYSIS. 

the other hand, anilin orange or caramel has been used, after pouring 
off the ether the curd will be colored more or less deeply, depending on 
the amount of color employed. In other words, of the three color- 
annatto, caramel, and anilin orange, the annatto only is extracted b 
ether. If caramel has been used", the curd will have a brown color a 
this stage; if anilin orange, the color of the curd will be a more or le^- 
bright orange. 

Tests for Annatto. — ^The ether extract, containing the fat and the 
annatto, if present, is evaporated on the water-bath, the residue is made 
alkaline with sodium hydroxide, and poured upon a small, wet filte: 
which wiE hold back the fat, and, as the filtrate passes through, will aUov: 
the annatto, if present, to permeate the pores of the filter. On washing 
off the fat gently under the water-tap, all the annatto of the milk used 
for the test will be found to have been concentrated on the filter, giving 
it an orange color, tolerably permanent and var\'ing in depth with the 
amount of annatto present. As a confirmatory test for annatto, stan- 
nous chloride may afterward be applied to the colored filter, producing 
the characteristic pink color. 

Tests for Caramel. — The fat-freed curd, if colored after the ether 
has been poured off, is examined further for caramel or anilin orange, 
by placing a portion of the curd in a test-tube, and shaking vigorously 
with concentrated hydrochloric acid. If the color is caramel, the acid 
solution of the colored curd wiU gradually turn a deep blue on shaking, 
as would also the white fat-free curd of an uncolored milk, the blue colora- 
tion being formed in a very few minutes, if the fat has been thoroughly 
extracted from the curd; indeed, it seems to be absolutely essential for 
the prompt formation of the blue color in the acid solution that the curd 
be free from fat. Gentle heat will hasten the reaction. It should be noted 
that it is only when the blue coloration of the acid occurs in connectior 
with a colored curd that caramel is to be suspected, and if muchcaramt-' 
be present, the coloration of the acid solution will be a brownish blue. I: 
the above treatment indicates caramel, it would be well to confirm its 
presence, by testing a separate portion of the milk in the following manner.* 

About a gill of the milk is curdled by adding to it as much strong 
alcohol. The whey is filtered off, and a small quantity of subacetate o: 
lead is added to it. The precipitate thus produced is collected uj-on a 
small filter, which is then dried in a place free from hydrogen sulphide. 
A pure milk thus treated yields upon the filter-paper a residue which i:r 

* See Nineteenth Annual Report of the Mass. State Board of Health Ci387), p. 183. 



MILK. 



177 



either wholly white, or at most of a pale straw color, while in the presence 
of caramel, the residue is a more or less dark-brown color, according to the 
amount of caramel used. 

Tests for Coal-tar Dye. — If the milk has been colored with an azo-dye, 
the colored curd, on applying the strong hydrochloric acid in the test-tube, 
will immediately turn pink. If a large amount of the anilin dye has been 
used in the milk, the curd will sometimes show the pink coloration when 
hydrochloric acid is applied directly to it, before treatment with ether, 
but the color reaction with the fat-free curd is very dehcate and unmistak- 
able.* 

Lythgoe'\ has shown that the amount of anihn orange ordinarily 
present in a milk for the purposes of coloring can be detected by adding 
directly to say 10 cc. of the sample an equal c^uantity of strong hydro- 
chloric acid and mixing, whereupon the pink coloration is produced, if 
the dye is present in more than minute traces. The test is more deh- 
cate if carried out in a white porcelain dish. It had best be used as a 
preliminar)' test only, and confirmed by a subsequent test on the fat-free 
curd as above. 

SUMMARY OF SCHEME FOR COLOR ANALYSIS. 

Curdle 150 cc. milk in casserole with heat and acetic acid. Gather curd in one mass. 
Pour off whey, or strain, if curd is finely divided. Macerate curd with ether in corked flask. 
Pour off ether. 



Ether Extract. 

Evaporate off ether, treat residue with 
NaOH and pour on wetted filter. After 
the solution has passed through, wash off 
fat and dry filter, which if colored orange, 
indicates presence of annatto. (Confirm 
by SnClj.) 



Extracted Curd. 

(i) If Colorless. — Indicates presence of 
no foreign color other than in ether extract. 

(2) // Orange or Bro-u'uish. — Indicates 
presence of anilin orange or caramel. 
Shake curd in test-tube with concentrated 
hydrochloric acid. 



If solution gradu- If orange curd im- 
ally turns blue, in- I vtediately turns pink, 
dicative of caramel, indicative of anilin 
(Confirm by testing orange, 
for caramel in whey 
of original milk.) 



Nature of Preservatives Used in Milk.— In most locahties 
having pure food laws preservatives in milk are regarded as adulterants. 

* Occasional samples of milk colored with a coal-tar dye of a different class from those 
already described have recently been found in Massachusetts. In these cases the color 
of the separated fat-free curd does not change when treated with hydrochloric acid. The 
color of the curd is, however, very marked, being deep orange, bordering on the pink. 

t Jour. Am. Chem. Soc, 22, 1900, p. 813. 



178 FOOD INSPECTION AND ANALYSIS. 

Their use, however, seems to be on the decrease. Of 6,i86 samples of milk 
examined by the Massachusetts State Board of Health during one year 
(1899) 71 samples, or 1.2%, were found to contain a preservative. Of 
these 55 were found with formaldehyde, 13 containing boric acid, borax, 
or a mixture of the two, and 3 contained carbonate of soda. 

Comparative tests have been made in the writer's laboratory of the 
keeping qualities of these commonly used milk preservatives, when present 
in varying strength, the milk being kept during the experiment at the tem- 
perature of the room, which at that season of the year (February) was about 
20° C* The preservatives were added about five hours after milking. 
The samples were titrated for acidity each morning, the acidity being 
expressed by the number of cubic centimeters of decinormal sodium 
hydroxide necessary to neutralize 5 cc. of the milk. 

The proportions of preservatives used in this experiment, as shown in 
the table on page 179, were intended to cover a wide range, from the 
weakest that could aid in preserving the milk up to a strength limited 
only by being perceptible to the taste. The table opposite shows the 
results. 

Formaldehyde, the most commonly used preservative for milk, is sold to 
the trade under various names, such as "Preservaline," "Freezine," "Ice- 
line," etc., all being dilute aqueous solutions of formaldehyde, containing 
from 2 to 6 per cent of the gas, being nearly always diluted from the 40% 
solution known as formalin. These preparations are usually accompanied 
by directions, which specify the amount to be used, varying from a table- 
spoonful of the solution in 5 to 10 gallons of the milk. It is commonly 
used in the strength of i part of the gas in 20,000, and rarely less than 
I part in 50,000. The antiseptic power of formaldehyde increases in a 
marked degree as the strength of the preservative is increased. Milk 
treated with i part in 10,000, for instance, according to the table was 
found to keep sweet 5 J days. In the strength of i part to 5000, the milk 
did not curdle for 10^ days, while i part of formaldehyde to 2500 parts of 
milk kept the milk from curdling for 55 days, the acidity up to that time 
being nearly normal. 

Formaldehyde is thus shown to be decidedly the most efficient of all 
milk preservatives, besides being inexpensive and convenient to use. 

Whether the growth of other bacteria than those that produce lactic 
fermentation is inhibited by formaldehyde in milk is not definitely settled. 
The claim has been made that pathogenic varieties are destroyed by its use. 
* Thirty-first Annual Report Mass. State Board of Health, 1899, p. 611. 



MILK. 



179 



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l8o FOOD INSPECTION AND ANALYSIS. 

Whether or not formaldehyde in milk is harmful to processes of diges- 
tion, when present in the amount commonly used, is still an open question.* 

Carbonate and Bicarbonate of Soda. — These substances are occasion- 
ally used in milk, though, as the above table shows, they possess little 
or no value as milk preserv^atives. They do, however, serve to neutralize 
the acidity of slightly soured milk and to postpone the time of actual 
curdling. 

Salicylic and Benzoic Acids, in view of the much more efficient anti- 
septics at hand, are now rarely used as milk preservatives, though the 
analyst should be on the outlook for them. Salicylic acid is a poor milk 
preservative, in view of the fact that it affects the taste of the milk, when 
present in sufficient quantity, to be of service. 

Detection of Formaldehyde. — Hydrochloric Acid Test.-\ — Commercial 
hydrochloric acid (specific gravity 1.2) containing 2 cc. of 10% ferric 
chloride per liter is used as a reagent. Add 10 cc. of the acid reagent to an 
equal volume of milk in a porcelain casserole, and heat slowly over the 
free flame nearly to boiling, holding the casserole by the handle, and giving 
it a rotary motion while heating to break up the curd. The presence of 
formaldehyde is indicated by a violet coloration, varying in depth with 
the amount present. In the absence of formaldehyde, the solution slowly 
turns brown. By this test i part of formaldehyde in 250,000 parts of 
milk is readily detected before the milk sours. After souring, the limit 
of delicacy proves to be about i part in 50,000. 

Various aldehydes, when introduced into milk, give color reactions 
under the above treatment, but formaldehyde alone gives the violet colora- 
tion, which is perfectly distinguishable and unmistakable. 

Hehner's Sulphuric Acid Test. — To 5 to 10 cc. of milk in a wide test- 
tube add about half the volume of concentrated commercial sulphuric 
acid, I pouring the acid carefully down the side of the tube, so that it forms 
a layer at the bottom without mixing with the milk. A violet zone at 

* Milk-dealers are led to believe, by artful dealers in preservative preparations, that the 
chemist cannot detect them. The manufacturer of a widely used preservative, a yfeak solu- 
tion of formaldehyde, issues an attractive pamphlet in which he makes the following remark- 
able claims: 

"It is not an adulterant. It immediately evaporates, so that no trace of it can be found 
as soon as it has rendered all the bacteria inert. No chemical analysis can prove its pres- 
ence in milk, quantitatively or otherwise." 

t Annual Report Mass. State Board of Health, 1897, p. 558; also 1899, p. 699. 

J The coloration produced seems to depend on the presence of iron salts in the acid, 
hence the use of commercial acid is recommended. If only pure acid is available, a little 
ferric chloride should be added 



MILK. i8l 

the junction of the two liquids indicates formaldehyde. This test mav 
be combined with the Babcock test for fat, noting whether a violet 
color forms on addition of the commercial sulphuric acid to the milk 
in the test bottle. 

Confirmatory Tests u-ith Distilled Milk. — If it is desired to confirm 
the above tests by further e^■idence, loo to 200 cc. of the milk sample 
are subjected to distillation, and the first 20 cc. of the distillate are used 
for testing. 

(i) To a few drops of this distillate in a test-tube add a drop of Schiff's 
reagent.* In presence of any aldehyde, a pink coloration will soon be 
perceptible, deepening in mtensity on standing. 

12) Add to 5 cc. of the milk distillate a few drops of a i^ aqueous 
solution of resorcin or phenol, and proceed as directed on page 820 Cpre- 
servativesj. The crimson color indicates formaldehyde, and not other 
aldehydes. 

(3j Use I or 2 cc. of the milk distillate and apply the phenylhydrazine 
test, page 820. 

(4) A small amount of the distillate from milk (which prior to distilling 
is acidified slightly with sulphuric acid to fix any free ammonia) is treated 
with a few drops of Xessler's reagent. t Traces of formaldehyde produce 
a yellow coloration, while if considerable fonnaldehyde be present, the 
color darkens on standing and a grayish precipitate may be formed. 

Detennination of Formaldehyde in Milk.i — To 100 cc. of milk add 
I cc. of 1:3 sulphuric acid and subject to distillation in a 500-cc. Kjeldahl 
nitrogen-flask, using a low circular evaporating burner to avoid frothing. 
According to Smith, the first 20 cc. of the distillate, or one-fifth the 
original volume, contain ver}' nearly one-third of the total formaldehyde. 
Collect 20 cc. of the distillate and determine the fonnaldehyde therein 
by the potassium cyanide method, as follows :§ 

Treat 10 cc. of tenth-normal silver nitrate with 6 drops of 50^ nitric 
acid m a 50-cc. flask, add 10 cc. of a solution of potassium cyanide con- 
taining 3.1 grams of KCX in 500 cc. of water, and make up to the 50-cc. 
mark. Shake, filter, and titrate 25 cc. of the filtrate with tenth-normal 
ammonium sulphocyanate,!' using ferric chloride as an indicator. 

* Table of reagents. No. 226. 

t Table of reagents, Xo. 187. 

i Smith, Jour. .\in. Chem. Soc., 25, 1903, pp. 1032 and 1037. 

§ Zeits. anal. Chem., 36, pp. 18-24. 

H Theoretically 7.6 grams per liter- On account of the deliquescent nature of the salt 
weigh out 8 grams, make up to a liter, and titrate against tenth-normal silver nitrate for 
its exact value, using ferric chloride as an indicator. Sutton, Volumetric .Analysis, Sth Ed. 
P- 155- 



1 82 FOOD INSPECTION AND ANALYSIS. 

Acidify another portion of lo cc. of tenth-normal silver nitrate with 
nitric acid, add lo cc. of the potassium cyanide solution to which the 
above 20 cc. of the formaldehyde distillate has been added. Make up 
the whole to 50 cc, filter and titrate as before 25 cc. of the filtrate with 
tenth-normal ammonium sulphocyanate for the excess of silver. 

The amount of potassium cyanide used up by the formaldehyde, in 
terms of tenth-normal ammonium sulphocyanate, is found by multiplying 
by two the difference between the two results, and the total formal- 
dehyde is calculated by multiplying by 3 the amount found in the 20 cc. 
of distillate. 

The reaction that takes place between the formaldehyde and the 
potassium cyanide probably results in the formation of an addition 
product as follows: 

CH20+KCN = KO.CH2CN. 

Detection of Boric Acid. — This is best accomplished by the turmeric- 
paper test applied either directly to the milk or to the ash (page 823). In 
the former case 10 cc. of milk are thoroughly mixed with 6 drops of 
concentrated hydrochloric acid, after which the tumeric paper is mois- 
tened with the mixture and dried. 

Determination of Boric Acid. — Use the method of Thompson.* Add 
10 cc. of a I : I solution of sodium hydroxide to 100 cc. of the milk, evaporate 
to dn'ness in a platinum dish, and proceed as described on page 823. 

Detection of Carbonate and Bicarbonate of Soda. — The addition 
of carbonates is manifest by the effervescence caused by treating the 
milk-ash with acid. Effervescence in the milk-ash is quite perceptible, 
when as much as 0-05% of sodium carbonate is present. 

Schmidt's method of detecting sodium carbonate or bicarbonate, 
when present to the extent of 0.1% or more, is as follows: Ten cc. of 
milk are mixed with an equal volume of alcohol, and a few drops of a 
1% solution of rosolic acid are added. If carbonate is present, a rose- 
red color will be produced, while pure milk shows a brownish-yellow 
coloration. The suspected sample thus treated should be compared 
with a similarly treated sample of pure milk at the same time. 

Detection of Benzoic Acid. — Shake 5 cc. of hydrochloric acid with 
50 cc. of the milk in a flask. Then add 150 cc. of ether, cork the flask 
and shake well. Break up the emulsion which forms by the aid of a 
centrifuge, or, in the absence of a centrifuge, extract the curdled milk 
by gently shaking with successive portions of ether, avoiding the forma- 

* Jour. Soc. Chem. Ind., 12, p. 432. 



MILK. 



183 



tion of an emulsion. A volume of ether largely in excess over that of 
the curdled milk has been found to be less apt to emulsionize.* Transfer 
the ether extract to a separator)^ funnel, and separate the benzoic acid 
from the fat by shaking out with dilute ammonia, which takes out the 
former as ammonium benzoate. Evaporate the ammonia solution in 
a dish over the water-bath till all free ammonia has disappeared, but 
before getting to dryness, add a few drops of ferric chloride reagent. 

The characteristic flesh-colored precipitate indicates benzoic acid. 
Care should be taken not to add the ferric chloride till all the ammonia 
has been driven off, otherwise a precipitate of ferric hydrate is formed. 

Detection of Salicylic Acid. — d) To 50 cc. of the milk add i cc. of 
acid nitrate of mercury reagent (p. 147), shake and filter. The filtrate, 
which should be perfectly clear, is then shaken with ether in a separator}' 
funnel, the ether extract evaporated to dryness, and a drop of ferric chloride 
reagent apphed. If salicylic acid be present, a violet color will be pro- 
duced. In carr}'ing out the test it should be noted that a small portion 
only of the salicyHc acid is in the filtered whey, the larger part being left 
in the curd. The color test is, however, so deUcate as to show its presence, 
when an appreciable amount is used. 

(2) Proceed exactly as directed for benzoic acid (p. 182). On apply- 
ing the ferric chloride to the final solution, after evaporation of the 
ammonia, a violet color shows the presence of saUcylic acid. 

Routine Inspection of Milk for Preservatives. — It was the writer's 
custom in Massachusetts to examine all the samples of milk collected 
during the months of June, July, August, and September for the com- 
monly used preservatives, in addition to the regular analysis for total 
solids and fat. The number of samples thus examined amounted to 
upwards of 500 per month, varying from 10 to 60 per day. The results 
of such an examination during four years are thus shown : f 
PRESERVATRTS IN MILK. 



Year. 


Number 
Samples containing 
Examined. Form- 
aldehyde. 


Per Cent 
containing 

Form- 
aldehyde. 


Number 

containing 

Boric 

Acid. 


Per Cent 

containing 

Boric 

Acid. 


Carbonate.^ tive 


1898 


1046 
2105 
20l8 

2154 
1934 


26 

55 
61 

42 
29 


2-5 
2.6 

3-0 
1.9 

1-5 


II I.O 


4 1 AT 


1800 


13 
6 

12 


0.6 

o'3 

n r 


3 

_ 


71 
67 

54 

A i 


1000 


IQOI 


IQ02 . 


I_L 0.7 — 






Totals. . . . 


9257 


213 


2-3 


56 , 0.6 1 7 1 376 



* WTien this process is used the ether may readily be recovered by distillation, 
t An. Rep. Mass. State Board of Health, 1902, p. 474; Analyst's Reprint, p. 22. 



1 84 FOOD INSPECTION AND ANALYSIS. 

Such a system by no means involves a large amount of time or labor, 
and is really essential before passing judgment upon the purity of the 
milk, since, unlike added color, there is nothing in the physical appear- 
ance of the milk to suggest the presence of preservatives, nor are they 
rendered apparent by the taste, if skilfully used. 

The methods employed are carried out as follows : * 

(i) Formaldehyde. — After having been examined for total solids 
and fat, the milk samples are arranged in order in their original con- 
tainers, and about lo cc. of each sample are poured into a casserole and 
tested in succession by means of the hydrochloric acid and ferric chloride 
test (p. i8o). A large stock bottle, which may be fitted with a siphon 
if desired, is kept on hand containing the hydrochloric acid reagent. 
Less than one minute is required in making the formaldehyde test for 
each sample. 

2. Carbonate and Boric Acid. — These tests have been so simplified 
as to be, as it were, a side issue in the process of cleaning the platinum 
dishes used for the determination of total solids. The various residues 
from the total solids are burnt to an ash in the original numbered dishes 
in succession, these dishes, after incineration, being arranged side by side 
on a flat tray. By means of a pipette, one or two drops of dilute hydro- 
chloric acid are introduced into each dish in succession, noting at the 
time any effervescence that may ensue, which is in itself an indication 
of sodium carbonate. After every milk ash has been acidulated, a few 
cubic centimeters of water are added to each dish by means of a wash- 
bottle, the dissolving of the ash being hastened by giving a rotary motion 
to the tray containing the dishes. A strip of turmeric-paper is then allowed 
to soak for a minute or so in each dish, after which it is withdrawn from 
contact with the solution and allowed to adhere to the side of the dish 
above the liquid, where it remains until dry. If the paper when dry 
is of a deep cherry-red color, turning a dark olive when treated with 
dilute alkali, the presence of boric acid is assured. These methods 
are, of course, preliminary tests for quickly singling out the preserved 
samples. Such confirmatory tests as are desired may in all cases be 
employed. 

Another method of drying the strips outside the dishes is as follows: 

In a part of the laboratory free from dust, two long sections of glass 
rod or tubing are placed in parallel lines over a strip of filter-paper, 

* Leach, Analyst, XXVI, p. 289. An. Rep. Mass. State Board of Health, 1901, p. 447 
Food and Drug Reprint, p. 27. 



MILK. 1 85 

with numbers marked on the paper at close intervals corresponding to 
the numbers of the platinum dishes. The strips of turmeric-paper, after 
soaking, are removed from the dishes and placed across the glass tubes, 
over the numbers corresponding to those of the dishes from which they 
were taken. Here they arc allowed to stand till dry, being kept in posi- 
tion by a third section of tube or rod placed over them. When dry, the 
color of the turmeric strips will indicate whether or not boric acid is present, 
and also the position will show in what sample to look for it. 

Cane Sugar. — This is alleged to be added for the purpose of increasing 
the total sohds of milk, but if present to any marked degree, it could 
hardly fail of detection by reason of the sweet taste imparted to the milk. 
Cane sugar in milk may be detected * by boiling 5 to 10 cc. of the sample 
with about o.i gram of resorcin and a few drops of hydrochloric acid foi 
a few minutes. In the presence of cane sugar, a rose-red color is pro- 
duced. 

According to Richmond, cane sugar may be estimated by first ascer- 
taining the total polarization of the sample as in the estimation of milk 
sugar (p. 147). The milk sugar is then determined by Fehling's solution 
(pp. 149 to 150) either volumetrically or gravimetrically. The difference 
between the anhydrous milk sugar found by the latter, or FehHng method, 
and that calculated by dividing the polarization by 1.217 will give the 
percentage of cane sugar present. 

Cotton's t method of detecting cane sugar, when present to the extent 
of 0.1%, consists in mixing in a test-tube 10 cc. of the suspected milk 
with 0.5 gram of powdered ammonium molybdate, and adding to the 
mixture 10 cc. of dilute hydrochloric acid (i to 10). Ten cc. of milk of 
known purity, or 10 cc. of a 6% solution of milk sugar are similarly treated 
by way of comparison. Both tubes are placed in a water-bath and 
the temperature gradually raised to 80° C. If cane sugar is present, an 
intense blue coloration is produced, while the genuine milk or the solution 
of milk sugar remains unchanged at the temperature of 80°. If the tem- 
perature is raised to the boiHng-point, however, the pure milk or milk 
sugar solution may also turn blue. 

Detection of Starch in Milk. — A small quantity of milk is heated in 
a test-tube to boiling, cooled, and a drop of iodine in potassium iodide 
added. A blue coloration indicates starch. 

* Richards and Woodman, Air, Water, and Food, p. i66. 
t Abs. Analyst, 1898, p. 37. 



1 86 FOOD INSPECTION AND ANALYSIS. 

Condensed Skimmed Milk as an Adulterant. — The use of condensed 
unsweetened skimmed milk to raise the solids of a skimmed or watered 
milk above the standard has been noted in Massachusetts. This sophis- 
tication is rendered apparent by the abnormally high solids not fat of 
the sample, which in some instances have exceeded ii%. A solid not fat 
in excess of io% is suspicious of this form of adulteration. By fixing a 
legal standard for both fat and solids not fat, such tampering with milk 
may readily be checked. 

Analysis of Sour Milk. — It occasionally becomes necessary for the 
analyst to deal with samples of sour milk, especially in the summer-time, 
when the milk has been brought from a long distance. While the process 
of lactic fermentation results in the formation of traces of volatile acids, 
unless the sample has become so badly curdled as to render an even homo- 
geneous mixture of the various parts impossible, a fair determination of 
the solids and fat can readily be made. Experience has proved that, 
excepting in instances of milk so badly soured as to have become actually 
putrid, the analysis of sour milk, if carefully made, should not differ 
materially from that of the same milk before souring. 

Care must be taken to secure an even emulsion of the curd and whey. 
This may sometimes be accomplished by repeatedly pouring the sample 
back and forth from one container to another. Again, it is sometimes 
necessary to use an egg-beater of the spiral wire pattern, which preferably 
should easily fit the can or milk-container. Unless a fine, even emulsion 
can be secured, it is impossible to make a satisfactory analysis of sour 
milk. With such an emulsion results can be relied on. 

In measuring portions of the thoroughly mixed sample of sour milk 
for analysis, a pipette should be used having a large opening.* 



CONDENSED MILK. 

Canned condensed milk has become a very important article of food, 
its use having increased considerably during the last few years. The 
universally accepted meaning of the term ' ' condensed milk" in this country 
is milk both condensed and preserved with cane sugar, being what is com- 
monly known in England as "preserved milk." The unsweetened variety 
is more often termed ' ' evaporated cream " and sold as such. It is, however, 

* A pipette open to the full size of the tube is convenient for this work. 



MILK. 



1S7 



as found on the market usually nothing better than condensed ordinan- 
milk, having no added sugar, and has generally no resemblance in com- 
position to cream other than in consistency. 

Condensed milk is usually prepared by boihng milk in vacuum-pans 
under diminished pressure to the proper degree of concentration. Up- 
wards of 350 samples of sweetened condensed milk have been analyzed 
in full in the laboratory of the Massachusetts State Board of Health in the 
course of eight years, representing no less than no brands, together with 
about 30 samples (representing 8 brands) of the unsweetened variety. 

In A'iew of the fact that a considerable number of the condensed-milk 
samples are shown by their analysis to have been produced from skimmed 
milk, the fat content in the samples analyzed varying from a mere trace 
to 12%, it is obvious that the typical composition of condensed milk could 
not fairly be shown by giving maximum, minimum, and mean resuhs 
from the entire tabulated series, nor would it be possible to draw a hard- 
and-fast Une excluding certain samples known to be adulterated in making 
up the averages. It has therefore been thought best to select a few typical 
brands and give their analyses in full. 

COMPOSITION OF SWEETENED CONDENSED MILK. 



L 



Points to be Noted. 



Total iw'ater -J ilk Cane Milk i Pro- ^ pg^^. 

Solids,' pgj. Solids, Sugar, Sugar, | teins, i pgj.' 

Ps'" Cent. P*^^ P^^ P^^ P^"" Cent. 
' Cent. I ' I Cent. Cent, i Cent. Cent. 



Fat in 

Ash, , Origi- 

Per ' nal 

Cent, ^ilk, 

I Per 

Cent. 



High in fat, much added 

sugar J79.17 

High fat, low milk sugar. ..' 68.70 
Low fat, high milk sugar; 

low proteins 69.30 

Normal constituents 

throughout* 74-29 

Condensed from skimmed , , 

milk ' 69 . 30 30 . 70 

Condensed from centrifu- 

gally skimmed milk 69.06 30.94 



20.83 
32.30 



30.70 
25.71 



31.32 47.8s 
30.27 38.43 

31.83 I 37-47 

32.37 I 41.92 

29.1s 40.15 

25. 88 43-18 



9-57 
6.38 

i6.7S 

11.97 

11.89 



7-95 
10.70 



6-34 



12.00 j 
1 1 . 46 



1.80 !4.6o 
1.73 



8.46 I 10.65 
12.15 I 3-o6 
II . 55 1 II . 78 0.09 



I -54 
1 . 29 

2.05 

2.46 



S-63 
2.77 
4.^6 
I . II 
Trace 



COMPOSITION OF UNSWEETENED CONDENSED MILK. 



Points to be Noted. 



Total .„. . 
SoUds, ' Water, 
Per I Per 
Cent. Ceiit- 



Milk i Pro- 1 _. ^ 

S^ar, teiQ ! Fat. 

Per ; pgj. Per 

Cent. I Cent. Cent. 



Ash, 
Per 
Cent. 



Fat. in,. No. of 
On&inal Times 
Milk. , Con- 
^er densed. 
Cent. 



High in fat ! 36 . 00 

Low in proteins i 31-25 

Normal constituents throughout* 28 . 16 

Condensed from skimmed milk . . | 35.17 



64.0c 
86.75 
69.24 
64.83 



10.65 
13-40 



11.63 
7.02 
8.66 

15-37 



12.00 
9.60 

8.10 
4. 20 



4.61 
4.18 

3. 68 
I. 28 



* Can be taken as being verj* near the average for all constituents in honest condensed milk of 
fair quality. 



1 88 FOOD INSPECTION ^ND ANALYSIS. 

In the case of sweetened condensed milk it will be observed that 
the proteins as a rule run considerably lower than the sugar, whereas 
in ordinar}^ cow's milk the percentage of proteins and milk sugar are 
more nearly alike. In making the above analyses all the reducing sugar 
was reckoned as milk sugar, whereas it is possible that a small amount 
of the cane sugar is inverted in the process of manufacture, and thus 
increases the amount of reducing sugar. 

U. S. Standards.* — Standard condensed milk and standard sweetened 
condensed milk are condensed milk and sweetened condensed milk re- 
spectively, containing not less than 28% of milk solids, of which not less 
than 27.5% is milk fat. Standard condensed skim-milk is skim- 
milk from which a considerable portion of water has been evapo- 
rated. 

ANALYSIS OF CONDENSED MILK. 

Preparation of the Sample. — For the analysis of condensed milk 
the following system of procedure has been adopted in the laboratory 
of the Massachusetts State Board of Health. The sample is first thor- 
oughly mixed, best by transferring the entire contents of the can to a 
large evaporating-dish, and working it thoroughly with a pestle till 
homogeneous throughout. Forty grams of the mixed sample are weighed 
out, preferably in a tared weighing-tray for sugar analysis, transferred 
by washing to a graduated loo-cc. sugar-flask (or if desired it is weighed 
directly into the flask) and made up to the mark with water. 

Total Solids. — An aliquot part of this mixed solution is further diluted 
with an equal amount of water, and 5 cc. of the diluted mixture, corre- 
sponding to I gram of the condensed milk, is pipetted into a tared platinum 
dish, such as is used for ordinary milk, the pipette being rinsed into the 
dish by means of a wash-bottle. The dish with its contents is then placed 
on the water-bath, and distilled water added by the wash-bottle till the 
dish is nearly full. It is allowed to remain in contact with the live steam 
of the water-bath for at least two hours after the last traces of water have 
been evaporated off to leave an apparently dry residue. It is then trans- 
ferred to a desiccator, cooled, and weighed. I 

It is of great importance to have the sample very dilute to properly 
determine the total solids in this manner. Formerly the sample was 
evenly distributed over asbestos fiber in the dish, but more accurate 
results were found possible by the above method. The character of 
the residue should be noted. It should not, excepting in the case of a 

* U. S. Dept. of Agric, Off. of Sec, Circ. 19. 



MILK. iSc, 

skimmed milk, be caked down hard and glossy on the bottom of the 
dish, but, if the operation is properly carried out, should have a well-sepa- 
rated fat layer at the top, and the residue should resemble in appearance 
that from ordinar}' milk. This result is accomplished by the extreme 
dilution of the sample. 

Ash. — The residue from the total solids as above obtained is care- 
fully burnt, cooled, and weighed as in the case of ordinary milk (p. 134). 

When the total solids are not to be determined, as in cases where 
the quality of the milk used in preparation of the sample is decided by 
the fat and ash alone (see p. 192), 12.5 cc. of the above 40*^ solution, 
corresponding to 5 grams of the sample, are evaporated to dr}-ness on 
the water-bath, and the residue burnt to an ash in the muffle or over a 
low flame. 

Fat. — The Authors Method. "^ — Fifteen cc. of the 40% solution pre- 
pared as above described, corresponding to 6 grams of the original con- 
densed milk, are measured into an ordinar}- test-bottle of the Babcock 
centrifuge. This is filled nearly to the neck with water, and 4 cc. of a 
solution of copper sulphate of the strength of Fehling's copper solution 
are added. The contents are thoroughly shaken, and the precipitated 
proteins, carr\'ing with them the fat are rapidly separated out by whirl- 
ing the fat bottle in the centrifuge, preferably without heating. The 
writer prefers an electric centrifuge of the Robinson type (p. 137) for 
this purpose, as the heat of the steam-driven machine cakes the precipitate 
down, so that it is harder to wash. If desired, the precipitate may be 
allowed to settle out of itself, which it does more quickly in the cold. 

The supernatant liquid containing the sugar is drawn off by means of 
a pipette of large capacity, having a stem sufficiently small to pass easily 
into the neck of the milk-bottle, a small wisp of absorbent cotton being 
first twisted over the bottom of the pipette to ser\-e as a filter. On with- 
drawing the pipette with the sugar solution, the cotton is wiped off into 
the bottle by rubbing against the inner side. 

The precipitated proteins and fat are given two additional washings, 
as above, by shaking thoroughly with water introduced nearly to the 
neck of the bottle, separating out in each case by centrifuge or by settling, 
and finally removing the washings with the pipette, two of such extra 
washings being found nearly always sufficient to remove all the sugar. 
If the precipitate is caked down hard after treatment with the centrifuge, 

* 28th An. Rep. Mass. State Board of Health, 1896, p 630, and Jour. Am. Chem. Soc., 
22, 1900, p. 589. 



I go FOOD INSPECTION AND /iN A LYSIS. 

it may be necessar)' to employ a stiff platinum wire as a stirrer to aid in 
mixing with the wash-water. 

Finally, enough water is added to amount approximately to the nor- 
mal volume of 17.6 cc. usually employed for the Babcock test, 17.5 cc. 
of sulphuric acid are added, and the test continued from this point on 
as in the ordinary Babcock process of milk-testing, multiplying the read- 
ing obtained by three to give the correct percentage of fat in the 
sample. 

For condensed milk containing no added cane sugar, these precau- 
tions are, of course, unnecessary, the ordinary Babcock method being 
directly employed with a weighed portion of the milk. 

Proteins. — Five cc. of the 40% solution originally prepared, corre- 
sponding to 2 grams of the condensed milk, are diluted further to about 
40 cc, and just enough of the Fehling copper solution is added, drop 
by drop, to precipitate the albuminoids, taking care to avoid a Targe 
excess. As a rule, 0.6 cc. of copper solution is ample for this. Nearly 
neutralize with sodium hydroxide, stopping just short of alkalinity, i.e., 
leaving the solution still slightly acid. An excess of alkali tends to dis- 
solve the casein and cause turbidity in the filtrate. Pass through a 
weighed filter-paper, wash, dry in an air-oven at 100° C, and weigh. The 
filter with the dry precipitate is then carefully burnt in a porcelain cru- 
cible,, and the difference between the weight of the dry precipitate and 
the weight of the ash is the weight of the proteins and fat. Expressing 
this in percentage, and deducting from it the per cent of fat previously 
obtained, the result is the per cent of proteins. 

Milk SugSLT.— Volumetric Process. — The filtrate and the washings 
from the preceding operation are made up to 100 cc. with water, and the 
amount of reducing sugar, obtained volumctrically by Fehling's solution, 
is reckoned as milk sugar. The titration is conducted in the manner 
described on p. 591. 

Assuming the solution to be exactly of the strength above described, 

100X0-067 
the milk sugar is calculated as follows : — ^-^ = Z-, where L is the 

»J y\ 0.02 

per cent of lactose or milk sugar, and 5' the number of cc. of milk 
solution, prepared as above required to reduce 10 cc. of Fehling's 
solution. Calculation may be avoided by the use of the following 
table, which may be employed when the above details are minutely 
carried out: 



MILK, 



191 



PER CENT MILK SUGAR CORRESPONDING TO NUMBER OF CUBIC 
CENTIMETERS USED. 

Strength of solution 2 grams in loo cc. 



Cu. Cm. 


Per Cent. 


Cu. Cm. 


Per Cent. 


i Cu. Cm. 


Per Cent. 


Cu. Cm. 


Per Cent. 


18.0 


18.61 


25.0 


13-40 


32.0 


10.47 


39-0 


8-59 


18.5 


18 


10 


25-5 


13-14 


32-5 


10.31 


39-5 


8.49 


19.0 


17 


(^3 


26.0 


12.89 


33-0 


10.15 


40.0 


8.37 


19-5 


17 


18 


26.5 


12.64 


33 - 5 


10.00 


40.5 


8.27 


SCO 


16 


75 


27.0 


12.41 


34-0 


9-85 


41.0 


8.17 


20.5 


16 


34 


27.5 


12.18 


34-5 


9.71 


41-5 


8.07 


21.0 


15 


95 


28.0 


11.97 


35-0 


9-57 


■42.0 


7-98 


21-5 


15 


5« 


28.5 


11-75 


35-5 


9-43 


42-5 


7.88 


22.0 


15 


22 


29.0 


11-55 


36.0 


9-30 


43-0 


7-78 


22.5 


14 


89 


29-S 


11-35 


36-5 


9.17 


43-5 


7.70 


23.0 


14 


5b 


30.0 


II. 16 


37-0 


9-05 


44-0 


7.61 


23-5 


14 


25 


30-5 


10.89 


37-5 


8-93 


44-5 


7-53 


24.0 


13 


95 


31.0 


10. So 


38.0 


8.81 






24-5 


13 


67 


31-5 


10.63 


38-S 


8.70 







Gravimetric Methods. — Lactose may be determined in the 40% 
solution of the condensed milk by the O'Sullivan-Defrcn method (page 
150), the Soxhlet method (page 150), or the Munson and Walker method 
(page 151), the solution being treated exactly as if it were milk. 

Cane Sugar. — This is obtained by difference, deducting the milk 
solids (the sum of the milk sugar, proteins, fat, and ash) from the total 
solids first obtained. 

Fat in Sweetened Condensed Milk. — Judgment as to the quahty of 
a given brand of condensed milk is naturally based more on its fat content 
than on any other one factor, in that, of all its constituents, the fat is the 
only one that can conveniently be tampered with to the detriment of its 
value as a food. Hence, an accurate method for the determination of 
the most important ingredient, the fat, is of great importance. 

The Babcock process without modification cannot be used, on account 
of the charring by the sulphuric acid acting on the cane sugar. 

The Adams-Soxhlet method is unreliable, because the large amount ox 
cane sugar is again a disturbing factor, enclosing the fat particles so firmly, 
when dried on the extraction coil, as to render its complete removal by 
the extracting ether difficult if not impossible.* In 1895 the writer's 
method described on page 189 was devised, and with certain minor modifi- 
cations has been used ever since with highly satisfactory results, proving 
itself to be not only much quicker than the Adams-Soxhlet extraction 



* When ordinary ether is used for the Soxhlet e.xtraction, the results may not appear too 
low because the alcohol and water present in the ether dissolve not only fat but also sugar, 
which goes in with and is weighed as fat. With ether carefully dehydrated and freed from 
alcohol or with benzine or petroleum ether, the fat results will always be found far too low 
when the extraction is conducted under ordinary conditions. 



192 FOOD INSPECTION AND ANALYSIS. 

method and easier of manipulation, but, indeefl, more accurate, by reason 
of the fact that the cane sugar with all its attendant troubles is first elimi- 
nated. 

Calculation of Fat in Original Milk. — The "fat in the original milk," 
as expressed in the tables on page 187, was calculated by assuming a 
percentage of solids not fat of 9.3 in the original milk, this being the standard 
fixed by the Massachusetts law. Calculate first the fat and the milk 
solids to the basis of the cane-sugar-free sample. This is done by divid- 
ing the per cent of each as found in the sample by 100 less the percentage 
of cane sugar, and multiplying the result by 100. Ascertain the dif- 
ference between the milk soHds and the fat thus obtained in the cane- 
sugar-free sample, and divide this percentage of milk solids not fat bv 
9.3. The result is the "number of times condensed " (if cane sugar were 
not present as a diluent). 

The per cent of fat in the cane-sugar-free sample, divided by the 
number of times condensed, as above obtained, gives the percentage of 
fat in the original milk. 

The above calculation from the solids not fat of the factor desig- 
nated as "the number of times condensed," necessitates determinations of 
fat, ash, proteins, and milk sugar, in fact, a complete analysis of the sample. 

A simpler method of calculating the " number of times condensed," 
involving determinations of fat and ash only in the sample, consists in 
dividing the per cent of ash found in the condensed milk by 0.7, this 
figure being the assumed ash of normal, standard milk. Then, by divid- 
ing the fat in the sample by the " number of times condensed " as last 
calculated, the result is the fat in the original milk. If this is found 
to be well below 3/,, there is reason to suspect that skimmed milk was 
used in its preparation. 

The " fat in the original milk " as thus calculated is, of course, an 
arbitrary factor and is useful only in deciding whether or not skimmed 
milk has been used in preparing the sample. By assuming the above 
very reasonable figures for the solids not fat, or for the ash of natural 
milk (according to which method is used for calculation), it is readily 
seen that the highest result is obtained for the " fat in the original milk " 
and hence the benefit of the doubt as to the use of skimmed milk is 
given to the manufacturer. 

Other Methods for Protein and Cane Sugar. — If desired, the proteins 
of condensed milk can be calculated from the total nitrogen obtained 
by the Gunning or Kjeklahl method, as in ordinary milk ({). 145). 

Bigelow and McElroys Polarimetric Method for Cane Sugar* — 26.048 

* Jour. .Am. Chem. Soc, 15, p. 668. 



MILK. 



19- 



grams of the mixed sample of condensed milk are transferred to a loo-cc. 
graduated sugar-flask and dissolved in water, which is boiled to make 
sure of normal rotation. The solution is then clarified by the addition 
of an acetic acid solution of mercuric iodide * and, if necessar)', alumina 
cream, the volume is made up to loo cc, shaken, and filtered through 
a dn." filter. Rejecting the first part of the filtrate, a further portion is 
polarized. For inversion, another sample of 26.048 grams is weighed 
out as before and dissolved, but before clarifying, is heated to 55° C. 
and treated with half a cake of compressed yeast, the heating \N-ith the 
yeast being continued at 55° for five hours. The clarifjing solution 
is added before cooUng, and, after cooling, making up to 100 cc, and 
filtering as before, the invert reading is obtained with the polariscope. 
By this process of yeast inversion the cane sugar only is inverted, the 
lactose remaining unchanged. It is best to work -^ith several samples 
and use the mean of the readings both for direct and invert figures. It is 
also best to use the double dilution method (p. 140) to compensate for 
the volume of the precipitated fat and proteins. 

The per cent of cane sugar is calculated by the formula of Clerget, 

a-h 



S = 



142.66 

2 



S being the per cent of cane sugar, 
a the direct reading, 

h the invert reading and / the temperature at which the obserN'ation is 
made. 
The above process presupposes the absence of invert sugar in the 
sample, a supposition which Wiley claims it is fair as a rule to assimie. 

CREAM. 

Composition. — Cream varies in composition according to the method by 
which it is obtained, i.e., whether (i) by allowing it to separate from the 
milk set in shallow pans, whence it is removed by hand-skimming, (2) by 
setting in deep vessels surrounded by cold water (as for example in the 
"Cooley" creamer) the skimmed milk being conmionly drawn off from 
below, or (3) by the centrifugal separator. Most of the hea\y cream 
found in the market at the present time is the product of the third or sepa- 
rator process. 

* Prepared by dissohing 53 grains of potassium iodide, 22 grams mercuric chloride, and 
32 cc. of strong acetic add in water and making up to i liter. 



194 



FOOD INSPECTION yiND ANALYSIS. 
COMPOSITION OF CREAM. 



Character of Cream. 





1 


-< 






46 


Konig 


Mean 


68.82 


18 


Leach 


Maximum 


S4-8o 






Minimum 


46.76 






Mean 


SI. 68 


18 


Leach 


Maximum 


8,V2Q 






Minimum 


70.50 






Mean 


77.89 



By natural separation 

By centrifugal separator 
"Heavy" cream 

"Light" cream 



3-76 



22.66 

46.40 
38.10 
42.02 
21.60 
8.60 
13.86 



4-23 



0-53 



31-18 

53-24 
45 -20 
48.32 
29.50 
16.71 
22.11 



8.42 

8.50 
4.20 
6.30 

9-3° 
7.22 

8.25 



Methods of Analysis. — The total solids, ash, sugar, and proteins are 
determined by similar processes to those used in milk analysis. 

Fal. — The most convenient method of estimating fat is slightly modi- 
fied from the regular Babcock process. The specific gravity of cream 





varies between such wide limits that it is 
best to weigh rather than measure the 
sample. Two varieties of cream bottle 
are in common use (Fig. 54) for the 
Babcock process, with a capacity for 
measuring 25 to 30 per cent of fat. 

Approximately 10 grams of the well- 
mixed cream sample are transferred to 
one of these cream bottles, previously 
tared, and the weight of the cream ac- 
curately obtained. A convenient pipette 
to use for the purpose is one the end of 
which has been broken off to the full size 
of the tube. 

Fig. 55 shows a cream-test scale spe- 
cially designed for weighing the sample^ 
provided with a sliding poise for counter- 
balancing the bottle, and a second weight 
for weighing the cream. The scale is 
delicate to o.oi gram when loaded. 
Five to 6 cc. of water are added to the 
cream in the bottle, after which the regular amount of sulphuric acid 
used in the Babcock milk test (17.5 cc.) are measured in, and the test 
continued in the regular manner employed for milk. The reading of 




Fig. 54. — Varieties of Babcock Test 
Bottle for Cream. 



MILK. 



195 



the fat is multiplied by 18 and the product, divided by the weight of 
cream taken, gives the per cent of fat. 

U. S. Standards.* — Standard Cream is cream containing not less than 
i87c of milk fat. 

Standard Evaporated Cream is cream from which a considerable portion 
of water has been evaporated. 

Adulteration of Cream. — In some localities fat standards are fixed 
for cream both "heavy" and "light," those falling below such standards 
being deemed adulterated. 

The same preservatives are employed in cream as in milk, and are 




Fig. 55. — A Babcock Cream-test Scale. 



detected in the same way. The color reaction for formaldehyde, by heat- 
ing with hydrochloric acid and ferric chloride, is not as delicate in the case 
of cream as of milk, by reason of the large amount of fat. Before making 
the test the sample is preferably diluted with an equal volume of water, the 
heating is done in a casserole as with milk, but finally pour into a test- 
tube, and observe the color of the aqueous layer. 

Gelatin in Cream. — Gelatin has been found by the writer in a number 
of samples of Massachusetts cream, its use being to increase the consistency. 
It was possible in one instance to obtain a sample of the adulterant used 
in the form of a powder, which proved on analysis to be chiefly gelatin 

* U. S. Dept. of Agric, Off. of Sec, Circ. 19. 



196 FOOD INSPECTION AND ANALYSIS. 

with a small mixture of boric acid, these ingredients serving the two-fold 
purpose of thickening and preserving the cream. 

Gelatin is best detected in cream or milk by the method of Stokes.* 
He uses for reagents (i) acid nitrate of mercury, prepared by dissolving 
metallic mercury in twice its weight of concentrated nitric acid (sp. gr. 
1.42) and diluting with twenty-five times its bulk of water, and (2) a 
saturated aqueous solution of picric acid. 

To about 10 cc. of the cream add the same amount of the acid nitrate 
of mercury solution and 20 cc. of cold water. The mixture is shaken vigor- 
ously and allowed to rest for five minutes, after which it is filtered. If 
much gelatin is present, the filtrate will not be clear, but opalescent. To 
the whole or a part of the filtrate a few drops of the picric acid solution 
are added, and if gelatin be present in any considerable amount, a yellow 
precipitate is formed. Avoid an excess of acid nitrate of mercury, as this 
would cause a precipitate with picric acid. 

If gelatin is present in small amount only, a cloudiness is produced, 
best seen against a dark background. In the absence of gelatin, the 
solution will remain perfectly clear after adding the picric acid. The 
reaction is delicate to i part of gelatin in 10,000 parts of milk or cream. 

Sucrate of Lime in Milk and Cream. — In the process of pasteuriz- 
ing cream, a process which is becoming more and more prevalent, the 
consistency becomes reduced, so that while the value of the cream is actu- 
ally enhanced on account of its freedom from bacteria and its increased 
capacity for keeping, its apparent richness is impaired when compared 
with untreated cream of the same composition. To restore this reduced 
consistency, Babcock and Russell f have shown that sucrate of lime may 
be used to advantage. They have appHed the term "viscogen" to this 
compound, and have suggested that cream so treated, in order to be sold 
legally, should be known by some distinctive trade name as "visco- 
cream" or "pasteurized visco-cream. " 

' ' Viscogen " is prepared by dissolving 2 J parts by weight of cane sugar 
in 5 parts water, and adding thereto, after straining, i part of quicklime 
slaked in 3 parts water. After shaking and settling, the supernatant 
liquid is syphoned off and bottled for use. It will thicken cream, milk, 
or condensed milk. The amount recommended to be added to cream 
should be two-thirds of the amount found by experiment necessary to 
neutralize its acidity. 

* Analyst, 22, p. 320. 

t Wisconsin Exp. Station Bulletin, 54. 



MILK. 



197 



Sucrate of lime in milk or cream is indicated by the presence of 
sucrose, in connection with an abnormally high alkalinity of ash and 
excessi\'c calcium oxide. These tests are carried out as follows: 

Lythgoe's Modification of Baier and Neuman's Test for Detecting 
Sucrose.* — To 25 cc. of milk or cream, add 10 cc. of a 5% solution of 
uranium acetate, shake well, allow to stand for 5 minutes, and filter. 
To 10 cc. of the clear fihrate (in the case of cream use the total filtrate, 
which will be less than 10 cc.) add a mixture of 2 cc. saturated ammo- 
nium molybdate and 8 cc. dilute hydrochloric acid (i part 25% acid 
and 7 parts water), and place in a water-bath at a temperature of 80° C. 
for 5 minutes. If the sample contains sugar, the solution will be of a 
Prussian blue color. This should always be compared in a colorimeter 
with the standard prussian blue solution, prepared by adding a few drops 
of potassium ferrocyanide to a solution of i cc, of 1% ferric chloride 
in 20 cc. of water. 

It has been claimed that pure milk will give this test. Occasional 
samples of pure milk will give a pale blue color, but this can be entirely 
removed by filtration and the filtrate will be green, while the color due 
to sugar will pass through the filter, giving the usual blue solution 
characteristic of adulterated samples. The color produced is due to a 
reduction of the molybdic acid, and is produced by levulose and dextrose, 
as well as by sucrose. Solutions of i gram of lactose, levulose, dex- 
trose, and sucrose in 35 cc. of water were used in comparing the amount 
of color produced when heated with the mol}'bdenum reagent for 5 
minutes. Lactose produced no color, levulose gave a heavy blue, sucrose 
a weaker blue, and dextrose the weakest blue, the colors of the last three 
corresponding in intensity as 10:3:1. 

Stannous chloride and ferrous sulphate give this blue color, but the 
reaction takes place in the cold, and, in small quantities, the color dis- 
appears on heating. In order for the color to persist after heating, the 
sample of cream must contain these substances to the extent of 1%, 
calculated as the metal. In this case the sample will be completely 
coagulated, and the taste will be very disagreeable. Hydrogen sul- 
phide will also give the blue color, but it will disappear on heating. If 
the solution does not show the blue color before heating, it is free from 
hydrogen sulphide, ferrous sulphate, and stannous chloride. 

As a confirmatory test for sugar, the resorcinc test may be applied 

* Zeits. Unters. Nahr. Genussm., i6, 1908, p. 51. 



igS FOOD INSPECTION AND ANALYSIS. 

to the serum prepared with uranium as described above. This test is 
given by sucrose and levulose, but not by dextrose or lactose. 

Determination of Alkalinity of Ash and Calcium Oxide. — Weigh 

25 grams of cream into a platinum dish, place in an oven at about 
125-150° C, over night, and burn to an ash in a muffle at a low-red 
heat. Dissolve the ash in 20 cc. N/io sulphuric acid, boil to expel 
the carbon dioxide, and titrate back with N/io sodium hydroxide, 
using phenolphthalein as the indicator. Express results as cc. N/io 
acid required to neutralize the ash of 100 grams of cream. 

Make the final solution of the above determination acid with acetic 
acid, heat to boiling, add i gram of sodium acetate, and to the clear 
solution add an excess of ammonium oxalate, boil for a few minutes, 
filter, and wash with water. Dissolve the calcium oxalate in hot dilute 
sulphuric acid, and titrate hot with N/io potassium permanganate. 
The number of cubic centimeters of N/io permanganate, multiplied by 
0.0112 (4X0.0028), gives the percentage of CaO in the sample. 

The alkalinity of the ash of 100 grams of a sample of cream treated 
by the writer with 5 cc. of viscogen per quart was found to be 18.8, in 
terms of N/io acid, added in excess and titrated back with N/io alkali, 
using phenolphthalein. The alkalinity of the ash of 100 grams of pure 
cream (7 samples) varied between 6.4 and 13.6. The calcium oxide 
and alkalinity of ash diminish as the fat increases. Cream samples 
treated with calcium sucrate, having a fat content from 26 to 33%, show 
as a rule an alkalinity of ash of from 14 to 18, and a CaO content of 
from 0.15 to 0.175%. Creams of the same class untreated show in general 
alkalinity of ash not exceeding 12.5 and a CaO content not exceeding 

0-I35- 

With higher fat contents both constants drop. For example, a cream 

of 45% fat containing calcium sucrate had an alkalinity of ash of 10.2 

and a CaO content of 0.12%. Cream of about 45% fat untreated had 

an ash alkalinity of 6.5 and a CaO content of 0.103%. 

ICE CREAM. 

For many years a wide variety of iced foods have been made and 
sold under the general name of ice cream, many of which are largely 
composed of ingredients other than milk or cream. In the study and 
classification of foods of such a miscellaneous nature as ice cream, in its 
popularly accepted meaning, it is not always easy to satisfactorily define 



MILK. 



199 



and fix standards. Whether, for example, the product should consist 
exclusively of frozen cream, sugar and flavoring, or v^hether eggs and 
other materials should be allowed under the unqualified name of ice 
cream, is a subject of some controversy. 

Properly speaking, many mixtures sold under the name should be 
otherwise designated, as, for example, " frozen custard," to specify more 
aptly their nature and composition. The following standards show 
the attitude of the government in this regard: 

U. S. Standards.* — Ice cream is a frozen product made from cream 
and sugar with or without a natural flavoring, and contains not less than 
14% of milk fat. 

Fruit ice cream is a frozen product made from cream, sugar, and 
sound, clean, mature fruits, and contains not less than 12% of milk fat. 

Nut ice cream is a frozen product made from cream, sugar, and sound, 
non-rancid nuts, and contains not less than 12% of milk fat. 

Fillers or Stiff eners. — In the manufacture of commercial " ice 
cream " substances are frequently added to cause the product to hold 
stiff and keep its consistency for many hours after freezing. The 
thickeners or fillers most commonly thus used are starch, gelatin, and 
gums such as gum tragacanth. Agar-agar and commercial casein are 
also said to be employed for this purpose. 

Preparations are on the market sold for thickening ice cream, con- 
sisting, as a rule, of one or more of the above-named substances. 

METHODS OF ANALYSIS. 

Fat. — H award'' s Method.^ — With a wide-mouthed, free-flowing pipette, 
weigh 18 grams of the freshly melted and mixed sample into a Babcock 
cream bottle. Add 3 cc. of chloroform, and water to about three-fourths 
the capacity of the bottle. Shake, add 10 cc. of Fehling copper solution, 
shake again, and whirl for three minutes in the centrifuge. The fat is 
confined to the underlying chloroform layer. If the supernatant liquid 
is turbid, gum tragacanth or gelatin is probably present, in which 
case add 2 or 3 cc. of N/io alkali, which causes these substances to pre- 
cipitate. 

Remove most of the supernatant liquid by aspiration through a narrow 
tube inserted in the cream bottle. Repeat the washing once, and then 

* U. S. Dept. of Agric, Office of Secretary, Cir. 19. 
f Jour. Am. Chem. Soc,. 29, 1907, p. 1623. 



200 FOOD INSPECTION AND ANALYSIS. 

blow in steam through a narrow tube till the chloroform is completely 
expelled. Cool, add water to a volume of 17.5 cc, and proceed as in the 
Babcock process for fat in milk. 

Second Method.'^ — Nine grams of the sample are weighed into the 
test bottle, and 30 cc. of a mixture of equal parts by volume of concen- 
trated hydrochloric acid and 80% acetic acid are added. Heat on the 
water-bath till the mixture darkens, but avoid charring. Whirl in the 
centrifuge, and read the percentage of fat directly, after adding hot water 
to run the fat layer into the neck. If charring has interfered with the 
fat reading, add ether after whirling to dissolve the fat layer, and draw 
off the ether solution into another bottle. Evaporate off the ether, fill 
with hot water, and again whirl and read. 

Examination of the Fat. — Enough of the fat is usually obtained 
from its determination in the Babcock bottle, as above, to examine its 
character with the refractometer. Cottonseed and other oils are some- 
times used as substitutes for milk fat. If a large amount of fat is 
needed, Howard suggests removing 30 to 40 cc. of the cream layer to a 
fat bottle, adding i cc. of acid nitrate of mercury and 20 cc. of petro- 
leum ether, and whirling in a centrifuge, afterwards removing the ethereal 
layer, washing with water, and evaporating the ether. 

Detection of Thickeners. — Patrick's Method. -\ — Add 25 cc. of water 
to 50 cc. of the sample, and boil till any thickener present is dissolved. 
Add 2 cc. of a 10% solution of acetic acid, heat to boiling, add 3 heap- 
ing teaspoonfuls of kieselguhr, and after shaking pass at once through 
a plaited filter. To 3 cc. of the clear filtrate add 12 cc. of 95% alcohol 
and mix thoroughly, thus precipitating the milk proteins not already 
removed, and also the gums and some of the gelatin, if much is present. 
Add 3 cc. of a mixture of 95 cc. of 95% alcohol and 5 ct. of concen- 
trated hydrochloric acid. This acidified alcohol dissolves completely the 
milk proteins, and, if a clear solution then remains, no gums or vegetable 
jellies have been used as thickeners. Turbidity does not, however, 
necessarily indicate presence of a thickener, as it may be caused by a 
large amount of eggs, or by the souring of the ice cream. Dilute the 
mixture, if turbid, by adding 3 cc. of water. Any precipitate due to 
gelatin or eggs will be dissolved at this dilution, but not that due to 
vegetable gums. If gum tragacanth be present, the precipitate will be 



* Rep. Illinois State Food Commissioner, 1906, p. S^. 
t U. S. Dept. of Agric, Bur. of Chem., Bui. 116, p. si5. 



MILK. 20I 

Stringy and cohesive, especially after shaking, while agar-agar or other 
vegetable thickeners will cause a fine flocculent precipitate. 

Souring of the ice cream sometimes produces a turbidity or precip- 
itate under the above conditions, which is not always dissolved after 
diluting wuth water. Formation of such a precipitate (due to sourness) 
may, however, apparently be prevented by the previous addition of 
formaldehyde to the sample. 

Howard'' s Test for Gums. — Precipitate lo cc. of the melted sample 
with acetone, and wash with 2 or 3 portions of dilute alcohol, using 
the centrifuge. Boil the washed residue with 6 to 8 cc. of water and 
I cc. of io9^ sodium hydroxide solution for half a minute. Cool, let 
stand a few minutes, filter, and heat the filtrate to boiling. Add one 
and one-half volumes of w^arm alcohol and shake. If agar-agar or gum 
tragacanth be present, a flocculent precipitate will immediately sepa- 
rate. Disregard a mere turbidity. To prove the absence of any con- 
siderable quantity of milk proteins in the precipitate, dissolve in cold 
water and saturate the solution with ammonium sulphate. 

Gelatin. — Use the method of Stokes (p. 196) on 10 to 15 cc. of the 
sample, disregarding a faint cloudiness at the end. 

Starch is detected by the usual iodine test. 

Preservatives. — Formaldehyde and boric acirl are tested for as in 
milk. 

BUTTER. 

The value of butter as a food depends almost entirely on its fat con- 
tent, although minute quantities of protein and milk sugar are also in- 
cluded in its composition. 

Hence butter is more logically treated in detail under the heading of 
fats (page 529). 

CHEESE. 

Nature and Composition. — Cheese consists principally of the curd 
and fat removed in a mass from milk, which has been curdled by the 
natural souring of the milk, or by the action of rennet. The separated 
mass of curd and fat, after being compressed, is allowed to undergo certain 
changes, w^hich constitute the ripening or curing, due to the action of 
micro-organisms and enzymes. Sometimes cream is used as the source 
of cheese and sometimes skimmed milk. During the ripening process, 
which requires from a few weeks to several months, the characteristic 



202 



FOOD INSPECTION AND ANALYSIS. 



flavor is developed by the changes which the proteins undergo, and the 
digestibihty of the cheese is improved. The nature of the proteolytic 
changes that take place during ripening are very little understood, but a 
variety of complex nitrogenous products are formed, which Van Slyke 
divides as follows: paracasein, unsaturated paracasein lactate, para- 
nuclein, caseoses (albumoses), peptones, amides, and ammonia. Besides 
nitrogenous bodies and fat, which are its chief constituents, cheese con- 
tains notable quantities of water, milk sugar, lactic acid, and mineral 
matter. 

In some kinds of cheese salt and coloring matter are added. 

Varieties. — Well-known cheeses of commerce are often named from 
districts, towns, or localities where they originated or are still made. 
They may be classified as cream, whole-milk, or skimmed-milk cheese, 
according to the quaHty of the product from which they are made, or 
again as hard, medium, or soft, according to whether (i) they are pressed, 
or (2) allowed to drain for days and sometimes weeks without pressure 
to a firm consistency, or (3) are made in the space of a few hours, being 
quickly drained on a sieve by hand pressure. 

Cheddar Cheese, which is the common cheese of the United States 
(though originally made some 250 years ago in England and still made 
there), is a type of the hard cheese. Stilton, an English, and Gruyhre, a 
Swiss cheese, belong to the medium class, and soft cheeses are represented 
by Brie and Neujchatel, both French cream cheeses. Other well-known 
varieties are Edam, a round, mild, long-keeping Dutch cheese, Camembert, 
a rich cream cheese, and Roquefort, made originally from ewe's milk in 
the French town of that name, and ripened in caves in the mountains. 
It is flavored by a peculiar mold. 

The following table, compiled by Woll,* shows the average composition 
of various cheeses of commerce, both foreign and domestic: 



Water. 


Casein. 


Fat. 


Sugar. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


34-38 


26.38 


32.71 


2-95 


32-59 


32-51 


26.06 


4-53 


30-35 


28.85. 


35-39 


1-59 


50-35 


17.18 


25. 12 


1.94 


44-47 


14.60 


33-70 


4.24 


31.20 


27.63 


33-16 


2.00 


36.28 


24.06 


30.26 


4.60 


35-80 


24-44 


37-40 




38.60 


25-35 


30-25 


2.03 



Ash. 



Cheddar 

Cheshire 

Stilton 

Brie 

Neufchatel 

Roquefort 

Edam 

Swiss 

Full cream, mean of 143 analyses. 



Per cent. 
3-58 
4.31 
3-83 
5-41 
2-99 
6.01 

4-90 
2.36 
4-07 



* Dairy Calendar, p. 223. 



MILK. 



203 



Van Slyke has furnished the following analysis of the nitrogen com- 
pounds in a sample of normal American Cheddar cheese six months 
old and cured at 60° F. : 



Per Cent i Per Cent 
N in 1 Water- 
Cheese, soluble N. 


Per Cent 

Xas 

Paracasein 

Mono- 

lactate. 


Per Cent Per Cent 
N as Para- N as 
nuclein. Caseoses. 


Per Cent 

N as 
Peptones. 


Per Cent 

N as 
Amides. 


Per Cent 

N as 
Ammonia. 


3.80 


. 1 
1.46 0.94 


1 
0.14 1 0.22 


0.18 


0.79 


0-13 



U. S. standards.* — Cheese is the sound, solid, and ripened product 
made from milk or cream by coagulating the casein thereof with rennet 
or lactic acid, with or without the addition of ripening ferments and 
seasoning, and contains, in the water-free substance, not less than 50% 
of milk fat. By act of Congress, approved June 6, 1896, cheese may 
also contain added coloring matter. 

Skim-milk Cheese is defined the same as cheese except that it is 
made from skim milk, and no minimum percentage of fat in the water- 
free substance is specified. 

Adulteration, — Cheese is commonly adulterated in two ways: first, 
by the partial or total substitution for the milk fat of a foreign fat, as 
oleomargarine or lard, and, second, by using skimmed milk as a mate- 
rial for its manufacture. 

In many localities a standard percentage for fat in cheese is fixed by 
law, as in the case of the U. S. standard noted above, all samples falling 
below that standard, unless sold as skim-milk cheese, being deemed adul- 
terated. 

Some states have specific standards for varying grades of cheese, 
classified as to their fat content. Thus under the Pennsylvania law f 
cheese is divided into five grades, as follows: 

Full-cream cheese must contain not less than 32% butter fat. 

Three-fourths cream cheese must contain not less than 24% butter 
fat. 

One-half cream cheese must contain not less than 16% butter fat. 

One-fourth cream cheese must contain not less than 8% butter fat. 

All cheese having less than 8% fat must be branded " Skimmed Cheese." 

The term "filled cheese" is commonly apphed to a product in which 
a foreign fat, as oleo oil or lard, has been used. Filled cheese is more 

* U. S. Dept. of Agric, Off. of Sec, Circ. 19. 
t Penn. Laws, C901, Act. 95, p. 128. 



204 FOOD INSPECTION AND ANALYSIS, 

commonly found in localities where a carefully enforced fat-standard 
law prevails, but, in the absence of a standard for fat in cheese, the manu- 
facturer can cheapen his product much more readily and conveniently 
by selling a skim-milk cheese in place of the whole-milk article, though 
not without producing a sensibly inferior product. 

METHODS OF ANALYSIS. 

Obtaining a Representative Sample. — Method of the A.O. A. C* — By 
means of a cheese-trier remove, if possible, three cyhndrical plugs from 
the cheese perpendicular to the surface and in length equal to about half 
the thickness of the cheese, one at the centre, one near the circumference, 
and one midway between the two. About one inch in length is cut off 
from each plug from the end having the rind, and this is discarded. The 
remaining portions of the plugs are then finely divided and mixed as 
intimately as possible. 

In place of the plugs a narrow, wedge-shaped segment may be cut from 
the cheese, reaching from the circumference to the center, the portions 
near the rind being removed, and the remainder of the piece being finely 
divided and mixed as before. Analyses should immediately be begun 
after obtaining the sample. 

Determination of Water.-^Two or three grams of the sample are 
carefully weighed in a tared platinum dish, and dried to constant weight 
in an oven at ioo° C. The loss of weight is reckoned as water. f 

Determination of Ash. — Ignite the residue from the moisture determina- 
tion at a low, red heat, cool in a desiccator, and weigh. 

Determination of Fat. — Lythgoe's Modified Babcock Method. — Weigh 
accurately about 6 grams of the sample in a tared beaker. Add lo cc. 
of boihng water, and stir with a rod till the cheese softens and an even 
emulsion is formed, preferably adding a few drops of strong ammonia to 
aid in the softening and emulsionizing, and keeping the beaker in hot 
water till the emulsion is tolerably complete and free from lumps. 

If the sample is a full-cream cheese, which is usually evident from 
its taste and appearance, a Babcock cream-bottle is employed. The 
contents of the beaker, after cooUng, are transferred to the test-bottle 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 46, p. 55. 

t Previously ignited sand or asbestos is recommended by some as an absorbent to be 
placed in the dish, but the writer gets better results in most cases directly as above. 



MILK. , 205 

as follows: Add to the beaker about half of the 17.6 cc. of sulphuric 
acid regularly used for the test, stir with the rod and pour carefully into 
the bottle, using the remainder of the acid in two portions for washing 
out the beaker. Finally proceed as in the regular Babcock test for milk. 
Multiply the fat reading by 18 and divide by the weight of the sample 
taken to obtain the per cent of fat. 

Short's Method.^ — Grind to a uniform powder 2 to 5 grams of the 
sample, and about twice its weight of anhydrous copper sulphate. Place 
a layer of anhydrous copper sulphate about 2 cm. thick on the bottom 
of the inner tube of a Johnson or Knorr extractor, add the ground mix- 
ture, and rinse the mortar first with a little anhydrous copper sulphate 
and finally with ether. Extract for 16 hours, evaporate the ether from 
the extraction-flask, and dry the fat in a boiling-water oven to constant 
weight. 

Werner-Schmidt Method. — Boil 2 to 3 grams of the sample in the 
Werner-Schmidt tube (p. 139) with 5 cc. of water and 10 cc. of con- 
centrated hydrochloric acid till, with constant shaking, all but the fat is 
dissolved. Cool, add 25 cc. of ether, and shake the tube well. Draw 
off as much as possible of the ether, after separation, in the usual manner, 
and extract with four or five additional portions of the solvent. 

Distil off the ether from the combined extractions, and weigh the fat. 

Determination of Protein. — From i to 2 grams of the cheese are 
treated by the Gunning or Kjeldahl method, adding after partial diges- 
tion a piece of copper sulphate the size of a pea to aid in the con- 
version.! NX 6.25 ^protein. 

Separation and Determination of Nitrogen Compounds. — Methods of 
Van Slyke. — Twenty-five grams of the sample are mixed in a porcelain 
mortar with an equal volume of clear quartz sand. Transfer the mix- 
ture to a 450-cc. Erlenmeyer flask, add about 100 cc. of water at 50° C., 
and keep the temperature at 50° to 55° C. for half an hour with frequent 
shaking. Decant the liquid through an absorbent-cotton filter into a 
500-cc. graduated flask. Treat the residue with repeated portions of 
100 cc. each of water, heating, shaking, and decanting as above till the 
nitrate, or water extract, at room temperature amounts to just 500 cc. 
exclusive of the fat floating on top, and use aliquot parts of this water 
extract for the various determinations. 

* U. S. Dept. of Agric, Div. of Chem., Bui. 35, pp. 15, 17, 225. 
t Van Slyke, N. Y. Exp. Station, Bulletin 215. 
% N. Y. Exp. Station, Bulletin 215. 



2o6 FOOD INSPECTION AND ANALYSIS. 

Water-soluble Nitrogen. — Determine the nitrogen by the Gunning 
method in 50 cc. of the above water extract, corresponding to 2.5 grams 

of cheese. 

Nitrogen as Paranudein. — Add 5 cc. of a i^c solution of hydrochloric 
acid to 100 cc. of the above water extract (corresponding to 5 grams of 
cheese), and keep the temperature at 50° to 55° till the separation is com- 
plete, as shown by a clear supernatant liquid. Filter, wash the precipi- 
tate with water, and determine the nitrogen therein by the Gunning 

method. 

Nitrogen as Coagulable Protein. — Neutrahze the filtrate from the 
preceding determination with dilute potassium hydroxide, and heat at 
the temperature of boihng water till the coagulum,* if any, settles com- 
pletely. Filter, wash the precipitate, and determine the nitrogen therein. 

Nitrogen as Caseoses. — Treat the filtrate from the preceding with i cc. 
of 50% sulphuric acid saturated with C. P. zinc sulphate, and warm to 
about 70° C. till the caseoses settle out completely. Cool, filter, wash 
with a saturated solution of zinc sulphate acidified with sulphuric acid, 
and determine the nitrogen in the precipitate. 

Nitrogen as Amides and Peptones. — Place 100 cc. of the water extract 
of cheese in a 250-cc. graduated flask, add i gram of sodium chloride 
and a solution containing 12% of tannin, till the addition of a drop to 
the clear supernatant hquid does not further precipitate. Dilute to the 
2SO-CC. mark, shake, pour upon a dry filter, and determine the nitrogen 
in 50 CC. of the filtrate, which gives the amount of nitrogen in the 
amido-acid and ammonia compounds. Deduct from this the amount of 
nitrogen as ammonia separately determined, and the difference is the 
amido-nitrogen. 

Nitrogen as peptones is obtained by subtracting the sum of the amounts 
of nitrogen as paranudein, coagulable proteins, caseoses, amido-bodies, 
and ammonia from the total nitrogen in the water extract. 

Nitrogen as Ammonia. — Distil 100 cc. of the filtrate from the above 
tannin-salt precipitation into standardized acid, and titrate in the usual 
manner. 

Nitrogen as Paracasein Lactate. — Treat the residue insoluble in water 
in obtaining the water extract, with several portions of a 5% solution 
of sodium chloride, to form a 500-cc. salt extract of the same, in an 
analogous manner to that employed in preparing the water extract. 
Determine the nitrogen in an aliquot part of this salt extract. 

* According to Van Slyke a precipitate at this point is rare in cheese. 



MILK. 207 

Determination of Lactic Acid.* — Add water to 10 grams of the cheese 
sample at 40° C. till the volume equals 105 cc. Shake and filter. Titrate 
25 cc. of the filtrate (equivalent to 2.5 grams of cheese) with tenth-normal 
sodium hydroxide, using phenolphthalein as an indicator. 

Each cubic centimeter of decinormal alkali is equivalent to 0.009 
gram lactic acid. 

Determination of Milk Sugar. — Boil 25 grams of finely divided cheese 
with two successive portions of about 100 cc. each of water, decant 
through a filter, and finally transfer the residue upon the filter and wash 
with hot water. Make up the entire aqueous extract thus obtained, when 
cold, to 250 cc, and determine the milk sugar by either Fehling method. 

Detection of Foreign Fat. — The cheese fat, separated in the manner 
described below, is subjected to the various processes detailed under 
butter, in precisely the same way, the fat of cheese being identical with 
that of butter. The most ready means for judging its purity consists 
in determining the refraction with the butyro-refractometer, and the 
Reichert number. 

Separation of the Fat for Examination. — Place a quantity, say 25 
grams, of the finely divided sample in a large Erlenmeyer flask, add about 
100 cc. of petroleum ether, cork the flask and allow it to stand for several 
hours with frequent shaking. Decant the petroleum ether through a 
filter, evaporate off the solvent by the aid of heat, and the residue will 
be found to consist of nearly pure fat. 

Or, wrap a sufficient portion of the finely divided sample in a mushn 
cloth, place this in a dish, and heat on the water-bath. The fat which 
runs out is afterward filtered and dried at 100°. 

Sufficient cheese fat may usually be obtained for the refractometer 
reading from the neck of the test-bottle, after completing the Babcock 
test, and, usually (except in the case of skimmed-milk cheese), for the 
Reichert number. 

Detection of Skimmed-milk Cheese. — In a cream cheese the fat 
should greatly exceed the protein; in a whole-milk cheese the per cent 
of fat should at least equal that of the protein, and is generally in excess. 
If the fat is considerably less than the protein, the cheese has undoubtedly 
been made from skimmed milk. The following analyses, made in the 
writer's laboratory, illustrate these grades: 

* U. S. Dept. of Agric, Bureau of Chem., Bui. 46, p. 56. 



208 



FOOD INSPECTION AND ANALYSIS. 



* By difference. 



Varieties of Cheese- 


Water. 


Fat. Protein.* 


Ash. 




37-63 
21.89 
55-95 


47.40 13-70 


1.27 


Whole milk (hard) 


38.00 

24.00 

15.20 

2.00 


37-71 
16.49 
21.36 
23-52 


2.40 


WVinle milk (?,oiX) 


3-56 


Skimmed milk (soft) 

Centrifugally skimmed milk (soft).. 


62-17 
72-80 


1.27 
1.68 



REFERENCES ON MILK AND ITS PRODUCTS.* 

Arkman. JSIilk, its Nature and Composition. London, 1899. 

Bmer, E., und Neumann, P. Ueber den Nachweis und die Beurteilung von Zucker- 

kalkzusatz zu Milch und Rahm. Zeits. Unters. Nahr. Genussm., 16, 1908, p. 51. 
Conn, H. W. Milk Fermentations. U. S. Dept. of Agric, Off. of Exp. Station, 

Bui. 9. 

Dairy Bacteriology. U. S. Dept. of Agric, Off. of Exp. Station, Bui. 25. 

Conn, H. W., and Esten. The Ripening of Cream. Storrs Exp. Station, Annual 

Report, 1900. 
DucLAUX, E. Le Lait. Paris, 1894. 
Ellis and Kenrick. Milk and Milk Adulteration. Canada. Int. Rev. Dept., Buls. 

21, 28. 
Farrington, E. H., and Woll, F. W. Testing Milk and its Products. Madison, 1908. 
Fleischmann, W. Lehrbuch der Milchwirthschaft. Bremen, 1893. 
Frear, W. American Milk and Milk Standards. Assn. State and Nat. Dairy and 

Food Depts., Proc, 1906, p. 172. 
Frerichs, K. Ueber d^n Nachweis von Zuckerkalk in^Milch und Rahm. Zeits. 

Unters. Nahr. Genussm., 16, 1908, p. 682. 
Gerber, N. Die Praktische Milch-Pruefung. 

Grotenfelt, G. The Principles of Modern Dairy Practice. New York. 
Herz, F. J. Untersuchung der Kuhmilch. Berlin, 1889. 

Howard, C. D. The Analysis of Ice Cream. Jour. Am. Chem. Soc, 29, 1907, p. 1622. 
HussoN, C. Le Lait. Paris, 1878. 

KiRCHNER, W. Handbuch der Milchwirthschaft. Berlin, 1891. 
Ladd, E. F. Proteids of Cream. Jour. Am. Chem. Soc, 20, 1898, p. 858. 
Leach, A. E., and Lythgoe, H. C. The Detection of Watered Milk. Jour. Am. 

Chem. Soc, 1904, 26, p. 1195. 
Le Clerc, J. A. Dairy Products. U. S. Dept. of Agric, Bureau of Chemistry, 

Bui. 6s, p. 35. 
Leffman, H., and Beam, W. Analysis of Milk and Milk Products. Philadelphia, 1893. 
Lehmann, J., und Hempel, W. Die Milchuntersuchungen. Bonn, 1894. 
Macfarlane, T. Milk and Milk Adulteration. Canada Inl. Rev. Dept., Buls. i, 

2, 9, ii» 17, 32, 43. 61, 74, 80. 

Cheese. Canada Inl. Rev. Dept., Bui. 6. 

Butter. Canada Inl. Rev. Dept., Bui. 16. 



* For references on Butter, see p. 562. 



MILK. 209 

Matthes, H., u. Muller, F. Ueber die Untersuchung des Milchserums mit dem 
Zeiss'schen Eintauchrefraktometer. Zeits. fiir offentl. Chem., 1903, p. 173. 

McGiLL, A. Condensed Milk. Canada Inl. Rev. Dept., Buls. 54, 69. 

Otto, A. Die Milch und ihre Produkte. Berlin, 1892. 

Pearmain, T. H., and Moor, C. G. The Analysis of Food and Drugs. Part I. Milk 
and Milk Proteids. London, 1897. 

Pearson, R. A. National and State Dairy Laws. U. S. Dept. of Agric, Bureau of 
An. Ind. Bui. 26, 1900. 

Richmond, H. D. Dairy Chemistry. London, 1889. 

Russell, H. L. Dairy Bacteriology. Madison, 1899. 

ScHERER, R., trans, by Salter, C. Casein: Its Preparation and Technical Utiliza- 
tion. London, 1906. 

Scholl. Die Milch. 

ScHRODT, M. Anleitung zur Priifung der Milch u. s. \v. Bremen, 1892. 

Sherman, H. C. Seasonal Variations in the Composition of Cow's Milk. Jour. Am. 
Chem. Soc, 28, 1906, p. 1719. 

On the Composition of Cow's Milk. Jour. Am. Chem. Soc, 25, 1903, p. 132. 

Snyder, H. The Chemistry of Dairying. Easton, 1897. 

Stutzer, a. Die chem. Untersuchung der Kase. Zeits. f. anal. Chem., 1886, p. 493. 

SwiTHiNBANK, H. Bacteriology of Milk. 1903. 

TouRCHOT, A. L. Milk end Milk Adulteration. Canada Int. Rev. Bui. 53. 

Van Freudenreich, E. Die Bakteriologie in der Milchwirthschaft. Basel, 1893. 

Van Slyke. Modern Methods of Testing Milk and Milk Products. New York, 1907. 

Woodman, A. G. On the Determination of Added Water in Milk. Jour. Am. Chem. 
Soc, 21, 1899, p. 503. 

Wanklyn, J. A. ]Milk Analysis. London. 

Weigmann, H. Die Methoden der Milchcons?rvirung. Bremen, 1893. 

Whitaker, G. M. The Milk Supply of Boston and other New England Cities. U. S. 
Dept. of Agric, Bur. of An. Ind. Bui. 26, 1900. 

Alabama Exp. Sta. Bui. 97. Dairy and Milk Inspection. 
Annual Reports of Inspector of Milk and Vinegar, Boston, Mass. 

" " " " Cambridge, Mass. 
Arkansas Exp. Sta. Bui. 45. Milk, its Decomposition and Preservation. 
Dairy Products. U. S. Dept. of Agric, Div. of Chem., Bulletin 13, part i, 1887. 
Die Milchzeitung. Bremen, 1872 et seq. 

Bacteria in Milk. 

Milk Fermentation and its Relations to Dairying. 

Souring of Milk. 

Facts about Milk. 

Milk as Food. 

Cheese-making on the Farm. 
Kansas Exp. Sta. Bui. 88. Keeping Milk in Summer. 
Maine Exp. Sta. Bui. 23 (New Series). Cream Preservation. 
Massachusetts State Board of Health Reports, 1883 et seq. 
Michigan Exp. Sta. Bui. 140. Ropiness in Milk. 
Minnesota Exp. Sta. Bui. 74. Milk and Cheese, Digestibility and Food Value. 



Farmers' 


Bulletin, No. 2. 




" 20. 




29. 




" 42. 




74- 




166. 



2IO FOOD INSPECTION AND ANALYSIS. 

New York (Geneva) Exp. Sta. Bui. 70. Reasons for Changing Milk Standards. 
« « " " " " 215. Estimation of Proteolytic Compounds in 

Cheese and Milk. 
" " (Ithaca) " " " 165. Ropiness in Milk. 

(I (< <( <' " <' IQC. " " " 

North Carolina Exp. Sta. Bui. 113. Testing of Milk. 

Oklahoma Exp. Sta. Bui. 21. A New Milk Test. 

West Virginia Exp. Sta. Bui. 58. Effect of Pressure in the Preservation of Milk, 

Wisconsin Exp. Sta. Bui. 48. Conn. Culture B. 41, in Butter-making. 

" " " " 52. Babcock vs. Gravimetric Tests for Fat. Acidity in Milk. 

" " " " 54. Restoration of Consistency of Pasteurized Cream. 

" " " " 61. Constitution of Milk with Reference to Cheese Produc- 

tion. 

" " " " 62. Tainted or Defective Milks. 

" " " " 70. Cheesc-curmg. 

" " " Annual Reports. 12th et seq. 

Zeitschrift dor Flcisch und Milch Hygiene. 



CHAPTER Yin. 



FLESH FOODS, 



MEAT. 

General Structure and Composition. — Meat is structurally made up 
of muscle fibers, held together by connective tissue, through which fat 
cells are usually more or less abundantly distributed. Each muscle fiber 
has a sheath or covering known as sarcolemma, formed of an albuminoid 
substance similar to elastin, and within the fibers are contained the meat 
juices, which are solutions in water of proteins, non-protein-nitrogcnous 
extractives, and salts. The substance of the connective tissue is made 
up largely of the albuminoids elastin (insoluble) and collagen, the latter 
being convertible by boiling with water or treatment with acids into gela- 
tin. The proteins of the meat juices consist chiefly of the globulin myo- 
sin (by far the most abundant), muscle albumin, and the muscle pigment 
hcemoglohin, or a substance closely analogous thereto. 

In the living muscle there are no peptones, but the ferment pepsin 
is present. After death, by the action of the pepsin in presence of lactic 
acid, a portion of the normal proteins of the muscle undergoes, as it were, 
digestion, so that in meat both peptones and proteoses * are found. 

The non-protein-nitrogcnous extractives are mainly creatin, xanlhin, 
hypoxanthin, and carnin, which, from their basic character, are known 
as flesh bases. 

The approximate proportions in which the chief constituents are present 
in meat is thus shown by Konig : 



I 



Water 75 . 



Nitrogenized compounds. 



to 77.0 
to 18.0 
to 



- Sarcolemma (muscle fiber) 13 

Connective tissue 2.0 

Albumin c.6 to 

Creatin 0.07 to 

Hy])Oxanthin o.oi to 

Crcatinin 

Xanthin Undetermined 

Inosinic acid 

Uric acid * . 

Urea o.oi to 0.03 



5-0 
4.0 

0-34 
0.03 



* A proteose or albumose known as myoalbumose normally exists in the live muscle. 

211 



FOOD INSPECTION AND ANALYSIS. 



to 


o.O 


to 


1.8) 


to 


0.50 


to 


0.08 


to 


0.07 


to 


0.05 


to 


0.01 


to 


0.50 


to 


0.04 



Fat 05 to 3.5 

' Lactic acid 0-05 to 0.07 

Butyric acid 1 

Other nitrogen-free compounds. . Formic^acid.' !!!'.'.!!!!'.!!! | Undetermined 

Inosite J 

[ Glycogen (0.3 

Salts (0.8 

Composed of: 

Potash o . 40 

Soda 0.02 

Lime o.oi 

Magnesia 0.02 

Oxide of iron 0.003 to 

Phosphoric acid 0.40 

Sulphuric acid 0.003 to 

Chlorine o.oi to 0.07 

Nitrogen compounds constitute by far the most abundant and im- 
portant portion of the substance of lean meat. Carbohydrates are almost 
entirely lacking, the small amount of glycogen and muscle sugar togethei 
constituting rarely more than i per cent. 

Glycogen (CgHioOs), sometimes called animal starch, is a white, amor- 
phous, tasteless, and odorless substance, when pure, much resembling 
starch. It is soluble in water, forming an opalescent solution, and is 
insoluble in ether and alcohol. With iodine a port-wine color is pro- 
duced, which disappears on heating and reappears on cooling. Glycogen 
is strongly dextro- rotary. It is converted to de.xtrose by boiling with 
dilute mineral acid. 

Muscle Sugar is either entirely absent m the living muscle, or exists 
in traces only. After death it is formed presumably from the glycogen, 
and exists in a very minute quantity, probably as dextrose. 

Inosite (C6H12O6+ H2O) is found in traces in the muscular substance of 
the heart, liver, kidneys, and testicles. 

Proximate Constituents of the Commoner Meats. — The chief charac- 
teristics of the flesh of various animals are in the main very similar, what- 
ever the nature of the animal. So true is this, indeed, that it is extremely 
difhcult from a chemical analysis to distinguish a particular kind of flesh 
when mixed with that of other animals in finely divided meat preparations, 
such as sausages, potted and deviled meats, and the like. 

The average composition of the commoner cuts of beef, veal, mutton, 
lamb, and pork, as well as of fowl and game, is shown in the following 
tables, compiled from the work of At water and Brj-ant,* the accompanying 
diagrams serving to locate, in the case of ordinary' meats, the portion of 
the animal from which the meat is taken. 

* U. S. Dept. of Agric, Off, of Exp. Stations, Bui. 28 (Revised Ed.). 



FLESH FOODS. 



213 




mmii^yt'^j:-- 



1. Neck 

2. Chuck 

3. Ribs 

i. Shoulder clod 
6. Fore shank 

6. Brisket 

7. Cross ribs 

8. Plate 



''fW 



9. Navel 

10. Loin 

11. Flank 

12. Rump 

13. Round 

It. Second cut round 
1). Hind shank 



Fig. 56. — Diagram Showing Cuts of Beef. 
COMPOSITION OF BEEF. 




Cut. 



Num- 
ber of 
Anal- 
yses. 



Refuse. 



Water. 



Protein. 



NX 
6.25. 



By 

Differ- 
ence. 



Fat. 



Fuel 
Value 

Ash. I per 

Pound. 
I Cals. 



Chuck: Lean — 
Medium- 
Fat— 

Ribs: Lean — 
Medium- 
Fat— 

Loin: Lean — 
Medium- 
Fat— 

Rump: Lean — 
Medium- 
Fat— 

Round: Lean — 
Medium- 
Fat— 



\ 



edible portion. 

as purchased, 
—edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
—edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
-edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
-edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased . . 
-edible portion. 

as purchased. . 

edible portion. 

as purchased. . 



4 
4 
4 
3 
6 
6 
15 
15 
9 



32 
32 
6 
6 
4 
3 

10 

10 

5 

5 

31 

29 

18 

14 

5 

3 



19 


-5 


15 


.2 


14 


-7 


22 


.6 


20 


8 


16.8 


13 


I 


13 


3 


10 


2 


14 





2C 


7 


25 





8. 


I 


7- 


2 



71-3 

57-4 
68.3 

57-9 
62.3 

53-3 
66.0 
52.6 
55-5 
43-8 
48-5 
39-6 
67.0 
58.2 
60.6 
52-5 
54-7 
49-2 
65-7 
56.6 
56.7 
45-0 
47-1 
36.2 
70.0 
64.4 

65-5 
60.7 
60.4 
54-0 



16.3 
19.6 
16.6 
18.5 

15-9 
16.5 
15.2 
17-5 
13-9 
15.0 
12.7 
19.7 
17. 1 
18.5 
16. 1 
17-5 
15-7 
20.9 
19. 1 
17.4 
13.8 
16.8 
12.9 
21.3 

19-5 
20.3 
19.0 
19-5 
17-5 



19-5 


15-7 
18.9 
16.0 


18.0 


15.4 
16.9 
14.8 


17.0 


13-5 


15.2 


12.4 


19-3 
16.7 
18.2 


15.8 
16.8 


15.0 
19.6 


17-5 
16.9 


13-4 
16.4 
12.6 


21.0 


19.2 
19.8 
18.3 


19.1 


17. 1 



8.2 

6.6 
II. 9 



15-9 
9.8 

9-3 
26.6 
21.2 
35-6 
30.6 
12.7 
II. I 
20.2 

17-5 
27.6 
24.8 
13-7 

11. 

25-S 
20.2 

35-7 
27.6 

7-9 

7-3 

13.6 

12.8 

19-5 

16. 1 



i.o 
0.8 
0.9 
0.8 
0.9 
0.7 
0.8 
0.7 
0.9 
0.7 
0.7 
0.6 
1.0 
0.9 
1.0 
0.9 
0.9 
0.8 
1.0 
0.9 
0.9 
0.7 
0.8 
0.6 
I.I 
1.0 
I.I 
1.0 



0.8 



720 
580 
865 
735 
"35 
965 
790 

675 
1450 
"55 
1780 

1525 
900 

785 
1 190 
1040 
1490 

1305 

965 

820 

1400 

mo 

1820 

1405 

730 

670 

950 

895 

1185 

1005 



214 



FOOD INSPECTION AND ANALYSIS. 




\ , Keck 

2. Chuck 

3. Shoulder 

i . Fore sliiink 
6. Breiv»t 



i!^i^'^ 



6. Ribs 

7 . Loin 
S. Flank 
O.Leg 

10. Hind shank 




Fig. 57- — Diagram Showing Cuts of Veal. 



COMPOSITION OF VE.AL. 





Num- 
ber of 
Anal- 
yses. 


Refuse. 


Water. 


Protein. 


Fat. 


Ash. 


Fuel 
N'alue 

per 

Pound. 

Cab. 


Cut. 


NX 
6.25. 


Bv 
Differ- 
ence. 


Chuck: Lean — edible portion. . 

as purchased 

Medium — edible jjortion . . 

as purchased. . . 

Ribs: Medium — edible porticm.. 

as purchased 

Fat — edible i)ortion. . 

as purchased 

Loin: Lean — edible portion . . 

as purchased 

Medium — edible portion . . 

as purchased.. . 

Fat — edible portion . . 

as purchased 

Leg: Lean — edible portion. . 

as purchased 

Medium — edible portion., 
as purchased.. . 


I 
I 
6 
6 
9 
9 
3 
3 
5 
5 
6 
6 

9 
9 

lO 

9 


19.0 
18.9 
25-3 
24.3 
22.0 

'16'. 5" 
"i&.'s 
9.1 
14.2 


76.3 
61.8 

73-3 
59-5 
72.7 

54-3 
60.9 
46.2 
73-3 
57-1 
69.0 

57-6 
61.6 
50.4 

73-5 
66.8 
70.0 
60.1 




20.6 
16.7 
19.2 
15-6 
20.1 

15-0 
18.8 
14.2 
19.9 
15.6 
19.2 
16.0 
18-5 
15-1 
21.2 

19-3 
19.8 
16.9 


1-9 
1.6 

6-5 

5-2 

6.1 

4.6 

19-3 

14-5 

5-6 

4-4 

10.8 

9.0 

18.9 

15-4 

4-1 

3-7 

9-0 

7-9 


1.2 
0.9 

I.O 

0.8 
I.I 
0.8 
1.0 
0.8 
1.2 
0.9 
I 
0.9 
1.0 
0.8 
1.2 
I.I 
1.2 
0.9 


465 






380 


19 
16 

20 

15 
18 

14 
20 

15 
19 
16 
18 

15 
21 

19 
20 

15 


7 


7 

5 
7 
2 

4 
9 
9 
6 

7 
3 
-3 
■ 4 
.2 

•5 


640 

515 
640 
480 
1 160 
87s 
615 
480 

825 
690 

II45 
935 

570 
520 

755 
620 



FLESH FOODS. 



215 




m^M'-^^ 



l.Neck 

2. Chuck 

3. Shoulder 

4 . Flank 
5 ■ Loin 
6. Leg 




Fig. 58. — Diagram Showing Cuts of Mutton. 
COMPOSITION OF MUTTON AND LAMB. 





Num- 
ber of 
Anal- 
yses. 


Refuse 


Water. 


Protein. 


Fat. 


Ash. 


Fuel 


Cut. 


NX 
6.25. 


By 

Differ- 
ence. 


per 
Pound. 
Cala. 


MUTTOX. 

Chuck: Lean — edible portion. . 

as purchased 

Medium — edible portion . . 

as purchased 

Fat — edible portion . . 

as purchased. . . 

Loin: Medium — edible portion . . 

as purchased 

Fat — edible portion . . 

as purchased 

Flank: Medium — edible portion . . 

as purchased. . . 

Leg: Lean — edible portion . . 

as purchased 

Medium — edible portion . . 

as purchased 

Lamb. 
Chuck: edible portion . . 
as purchased. . . 
Leg: Medium — edible portion. . 

as purchased 

Fat — edible portion. . 

as purchased 

Loin: edible portion. . 
as purchased 


I 
I 
6 
6 
2 
2 

13 
12 

3 
3 
8 
2 
3 
3 
11 
II 

I 
I 
2 
2 

I 
I 
4 
4 


19-5 

21-3 

16.0 
II. 7 

9-9 

'i6!8' 

18.4 

19. 1 
17.4 

13-4 
14.8 


64.7 
52-1 
50-9 
39-9 
40.6 

33-8 
50.2 
42.0 
43-3 
38-3 
46.2 

39-0 
67.4 

56.1 
62.8 
51-2 

56.2 
45-5 
63-9 
52-9 
54-6 
47-3 
53-1 
45-3 


17-8 
14-3 
15-1 
II. 9 

13-9 
II. 6 
16.0 

13-5 
14-7 
13.0 
15.2 
13-8 
19.8 
16.5 
18.5 
I5-I 

19. 1 

15-4 
19.2 

15-9 
18.3 

15-8 
18.7 
16.0 


18. 1 

14.5 
14.6 

"-5 
13-7 
11-5 
15-9 
13.0 
14.2 

12-5 
14.8 

13-6 
19. 1 

iS-9 
18.2 
14.9 

19.2 

15-5 
18.5 
15-2 
17. 1 
14.8 
17.6 
15-0 


16.3 

13-I 
33-6 
26.7 

44-9 
37-5 

28.3 

41-7 
36.8 

38-3 
36-9 
1^-4 
10.3 
18.0 
14.7 

23.6 
19.1 
16.S 
13-6 
27.4 

23-7 
28.3 
24.1 


0.9 
0.8 
0.9 
0.6 
0.8 
0.7 
0.8 
0.7 
0.8 
0.7 
0.7 
0.6 
I.I 
0.9 
1.0 
0.8 

1.0 
0.8 
I.I 
0.9 
0.9 
0.8 
1.0 
0.8 


1020 
820 
1700 
1350 
215s 
1800 

1695 

1445 

2035 

1795 

1900 

1815 

890 

740 

1 105 

900 

1350 
1090 

105s 

870 

1495 
1295 
1540 
1315 



2l6 



hOOD INSPECTION AND ANALYSIS. 



\ 




7 


3 


8 


-^ 


\ 






4 


7 ' K 


l 






5 


y.i 




1. 


Head. 






2 


Shoulder. 






3. 


Buck. 






4. 


Middle cut. 






5. 


Ikilly. 






C. 


Ham. 






7, 


Ribs. 








8 


Loin 








Fig. 59- — Diagram Showinj^ Cuts of Pork. 
COMPOSITION OF TORK, 1M)ULTRY, .\ND GAME. 



Cut. 



Num- 
ber of 
Anal- 



Refuse. 



Water. 



NX 
G.25. 



By 
DifTcr- 



Fnt. 



Ash. 



Fu.-l 
\aluo 

per 
PouikI 
Cals. 



roi?K. 

Shoulder: cilihlc portion. 

as purihascd. . 
Loin: Loan — odihU- portion. 

as i)ur(hascd. . 
Fat — edible ])orlion. 

as purchased. . 
Ham: Lean — edible jHirlion. 

as pvuxhased. . 
Fat — edil)le ].ortion. 

as purchased. . 

Poultry and Gamk. 
Chicken: edible ]iortion. 

as purchased. . 
Fowl: edible jMirtion. 

as ]nirihased. . 
Goose: edible portion. 

as purchased . . 
Turkey: edible jiortion. 

as purchased.. 
Quail: as purchased . . 



5 
5 

3 
3 

26 
26 



12.4 



23-5 



0.9 
13.2 



51-2 

44-9 
60 . 3 
46. 1 
41.S 

34-.^ 
60.0 

59-4 



13-3 
12.0 
20.3 
15-5 
14-5 
11.9 
25.0 
24.8 
12.4 



13.8 
12.2 
19.7 
15-1 



41.6 



25-9 
17.6 
22.7 



74 


8 


43 


7 


03 


7 


47 


I 


46 


7 


3« 


5 


55 


5 


42 


4 


66 


9 



12.8 

19-3 
13-7 
16.3 

13-4 

21. I 
16. 1 
21.8 



lO.O 

24-3 

24.2 

10.6 

y.2 

21.6 
12.6 
10.0 
14.0 
16.3 

13-4 
20.6 

15-7 



34-2 
29.8 
19.0 
14-5 
44-4 
37-2 
14.4 
14.2 
50.0 
43-5 

2-5 

1.4 
16.3 

12.3 
36.2 
29.8 
22.9 
18.4 
8.0 



0.8 
0.7 

I.O 

0.8 
0.7 
0.6 

1-3 
1-3 
0.1 

0-5 

I.I 
0.7 



0.7 
0.8 
0.7 



1-7 



1 690 
14S0 
1 1 80 
900 
2145 
1790 

1075 
1060 

2345 
2035 

505 

295 

1045 

775 
1830 

1505 
1360 

1075 

775 



FLESH FOODS. 



217 



Characteristics of Sound Meat. — The reaction of meat should be acid. 
If neutral or alkaline, decomposition is indicated, except that alkalinity 
may be due to the use of alkaline salts as preservatives. 

Letheby * gives the following characteristics of sound, fresh meat. In 
color it is neither pale pink nor deep purple, the former indicating that 
the animal v^as affected with some disease, and the latter that it died a 
natural death, and was not slaughtered. In appearance it is marbled, 
due to the presence of small veins of fat distributed among the muscles. 
In consistency it is firm and elastic to the touch, and should hardly moisten 
the finger; a wet, sodden, or flabby consistency with a jelly-like fat is 
indicative of bad meat. As to odor, it is practically free ; whatever orlor 
there is should not be disagreeable; a sickly or cadaverous smell is indica- 
tive of diseased meat. After standing for a day or so, it should not become 
wet, but on the contrary should grow drier. When dried at 100° C. it 
should not lose more than 70 to 74 per cent in weight; unsound meat 
frequently loses 80% or more. It should shrink very little in cooling. 

Inspection of Meat. — While carefully drawn laws exist almost every- 
where relating to the sale of meat, and government inspectors are ap- 
pointed to carry out the requirements of the laws, yet in this country there 
is undoubtedly some meat unfit for foorl on the market, owing to the 
-mall number of inspectors, and the consequent comparative safety with 
which unscrupulous dealers may sell meats forbidden by law and escape 
fletection. The insp'.ctlon of meats and fish under municipal ordinances 
is not always carried out as thoroughly as might be desired. 

Unwholesomeness 0} Meat may be due to a diseased condition of the 
animal while alive, or to poisonous or injurious toxins developed by 
the action of bacteria after death. In the first case, the diseased conditions 
may be due to temporary causes only, or to the presence of animal parasites, 
such as trichina; in pork, or as the result of pathogenic bacteria, causing 
such serious diseases as tuberculosis, anthrax, glanders, etc. It thus 
requires much skill and judgment on the part of the meat-inspector 
to correctly pass upon the suitability for food of the various meats as 
they appear on the market. Coplin and Bevan f give in detail useful 
data regarding the inspection of meat, as well as of the animal before 
slaughtering, showing the requisite size, weight, age, conditions of health 
etc., that should obtain. The detailed physical and microscopical exami- 
nation involved in such inspection is, however, rarely germane to the 
work of the public food analyst, and will not be treated of in this manual. 

* Lectures on Food, p. 210. f Practical Hygiene, pp. 130-157. 



2i8 FOOD INSPECTION AND ANALYSIS. 

It is also beyond the scope of the present work to treat of the harmful 
toxins developed by bacterial action in meat and fish, causing what is 
known as ptomaine poisoning. The work of detecting and isolating 
such poisons comes within the province of the bacteriologist and biolo- 
gist, rather than that of the chemist, involving many experiments upon 
guinea-pigs, rabbits, or other animals not usually found in the chemist's 
laboratory. It has furthermore been recently shown by Vaughn and 
Novy * that even when these toxins are present in foods in sufficient 
quantity to produce serious results, very considerable amounts of the 
food must be taken in order to isolate them by chemical means, more, 
in fact, than is usually available for analysis. 

For the general inspection of meats for animal parasites, poisonous 
toxins, etc., the reader is referred to such works as those of Vaughn and 
Novy, Fischoder, Walley, Andrews, Cobbold, and Salmon as cited in the 
references on pages 258 to 260. 

U. S. Standards.! — Standard Meat is any sound, dressed, and properly 
prepared edible part of animals in good health at the time of slaughter. 
The term "animals" as herein used includes not only mammals, but 
fish, fowl, crustaceans, moUusks, and all other animals used as food. 

Standard Fresh Meat is meat from animals recently slaughtered, or 
preserved only by refrigeration. 

Standard Salted, Pickled, and Smoked Meats are unmixed meats pre- 
served by salt, sugar, vinegar, spices, or smoke, singly or in combination, 
whether in bulk or in packages. 

Standard Manufactured Meats are meats not included in the above 
divisions, whether simple or mixed, whole or comminuted, with or without 
the addition of salt, sugar, vinegar, spices, smoke, oils, or rendered fat, 
if they bear names descriptive of their composition, and when bearing such 
descriptive names, if force or flavoring meats are used, the kind and 
quantity thereof are made known. 

Preservation of Meat. — Raw meat soon begins to decompose, unless 
precautions are taken to destroy, or at least check the growth of putrefying 
bacteria. From earhest times the subjection of meat to extreme cold 
has been practiced in order to enhance its keeping qualities. Bacterial 
growth is inhibited to a greater or less extent by refrigeration, by sub- 
jecting the meat to the various processes of curing, by the use of high 
temperatures and the exclusion of air as in canning, and by the employ- 
ment of antiseptics. 

* Cellular Toxines. f U. S. Dept. of Agric, Off. of Sec, Circ. No. 19. 



FLESH FOODS. 219 

Refrigeration may consist (i) in actually freezing the meat^ 
in which condition it may be kept without decomposition almost 
indefinitely, until finally thawed for use, or (2) in keeping the meat 
at or near the temperature of freezing without actually congealing 
it, as is done by the use of the ordinary refrigerator. The second 
method, while much less efficacious than the first, serves to prevent 
decomposition for a considerable time and is preferred for beef, 
mutton, and pork. The lower temperatures are employed with poultry 
and game. 

Curing consists in subjecting the meat to various processes of drying, 
smoking, pickling, corning, etc., or to a combination of these processes. 
In simple drying, the meat is subjected to the heat of the sun or to artificial 
heat. In smoking, which is commonly practiced on beef and ham, the meat, 
which may or may not be first salted or otherwise treated, is exposed for 
some time to the smoke of burning beech or hickory wood, during which 
it becomes to some extent impregnated with the antiseptic properties of the 
creosote and pyroligneous acid, at the same time being dried by the heat 
of the burning wood. In some cases best results are obtained by a slow 
smoking at a comparatively low temperature, while in others quick, hot 
smoking is found most efficacious. The character of the meat is decidedly 
changed by smoking, and, according to Utescher, smoked meat is always 
alkaline in reaction. In pickling^ the meat may be treated with dry 
salt and subjected to pressure, so that the meat juice forms the liquid 
for the brine, in which it is allowed to remain for some time; or, as in 
the ordinary process of corning, the beef is soaked for some days in a 
strong solution of salt to which a little saltpetre (KNO3) has been added. 
In the process of pickhng, the salts from the brine slowly diffuse into 
the interior of the meat by osmosis, a part of the soluble albumin passing 
out into the brine. The effect of the saltpetre is to preserve the natural 
red color of the meat, which by the action of salt alone becomes destroyed, 
or at least impaired. 

Bacon and ham are frequently cured by pickling in brine containing 
salt, saltpetre, and cane sugar, and sometimes also such antiseptics as 
boric acid and calcium bisulphite. 

The curing of bacon is sometimes effected by injecting the pickling 
fluid into the tissues with a " pickle-pump," capable of exerting a pressure 
of 40 lbs. to the square inch, and provided with a hollow, perforated 
needle-nozzle, which penetrates the flesh. After pickling, the bacon or ham 



2 20 FOOD INSPECTION ^ND ANALYSIS. 

may be simply dried, or, if desired, smoked. Oak sawdust is frequently 
burned for the smoking of ham. 

The Use of Antiseptics in Meat. — Most of what might be termed 
the modern preservatives are to be looked for in one or another of the 
various meat preparations, though some are better adapted than others 
for use in particular cases, as will be seen by reference to the composition 
of typical commercial preservative mixtures given on page 817. 

Borax and boric acid, usually in mixture, have been used more com- 
monly than any other preservatives for the preservation of meat. Like 
salt, they are used commonly in surface application, in the case of large 
cuts of meat, or by mixing, in the case of sausage meat. A more recent 
method of application consists in impregnating the tissue of the meat 
with a solution of the boric mixture, by means of the above-described 
pickle-pump. The use of boric acid and its compounds, however, is not 
permitted under the regulations of the Federal meat inspection law of 
the United States and Germany. 

Sulphurous Acid. — As much as 1% of a solution of sulphurous acid may 
be added to meat without being apparent to the taste or smell. Mitchell 
quotes Fischer as having found that 50% of the preserved meat products 
(sausages, etc.) sold in Breslau in 1895 contained sulphites, varying in 
amount from o.oi to 0.34 per cent of sulphur dioxide. Calcium bisulphite 
is a salt commonly employed. In Hamburg steak it serves partly as a 
preservative, but chiefly as a deodorizer and a restorer of the bright red 
color of fresh meat. 

Salicylic Acid is not of such common occurrence in meat products as 
the other antiseptics mentioned. The writer has found it in prepared 
mince-meat. 

Among other preservative substances sometimes used with meat are 
solutions containing phosphoric acid and aluminum salts. 

The toxic effects of these and other antiseptic chemicals in meats, and 
the most practical means of controlling their use are questions in con- 
troversy, presenting no new phases that have not been elsewhere dis- 
cussed in treating of the general question of preservatives in food. 
Methods of detecting preservatives in meats are given elsewhere. 

Effect of Cooking on Meat. — The general result of cooking is to render 
the meat less tough, to develop an agreeable flavor, and to coagulate more 
or less of the proteins. When subjected to moist heat, such as boil- 
ing and steaming, some of the soluble materials are dissolved, so that 
when the liquor in which the meat is boiled is thrown away, some of the 



FLESH FOODS. 221 

valuable substances are lost. This is especially true when meat is placed 
in cold water which is afterwards brought to boiling, a method to be 
recommended when the liquor with the dissolved extractives is to be used 
for broth. When the meat to be boiled is placed at once in boiling 
water, there is less loss of soluble matter by reason of the formation of a 
more or less impenetrable coating on the outside, by the coagulation of 
the proteins. Meat that is boiled becomes softer, owing to a partial 
dissolving of the gelatin formed. In the dry cooking of meat, as by 
broiling or roasting, there is usually a hardening of the tissues, and a 
driving out of some of the meat juices, which are, however, often recovered 
in the form of gravies. 

Canning of Meat. — By far the most effective method of preserving 
meat and meat preparations of all kinds for long periods of time, consists 
in the application of the principle of sterilizing by heat, and sealing in 
air-tight cans. The process of canning cooked meat and its products 
does not differ materially from that employed in the similar preparation 
of vegetables. (See Chapter XXI.) Previous to canning, the meats 
are usually cooked by boiling, during which process the changes described 
in the preceding paragraph take place. 

The practice of misbranding chopped meat with respect to variety 
has been very prevalent in the past, and many varieties of so-called potted 
and devilled meats and game have frequently consisted wholly or in large 
part of a cheaper variety than that specified on the label. This j^ractice 
has been largely corrected in this country, owing to the enforcement of 
the regulations of the Federal meat inspection law. 

It is largely among the canned meats and prepared meat products 
that instances of adulteration are to be found, since the fresh meats in 
whole cuts are rarely subject to adulteration. 

Preservatives are sometimes added to canned meats, especially in 
the case of dried and smoked beef, ham and bacon, and in the potted 
and devilled mixtures. Boric acid, benzoic acid, and sulphites have 
been found in these preparations. 

It is believed, however, that this [)ractice has been largely discontinued, 
owing to the enforcement of the Federal regulations mentioned above. 

Composition of Canned Meats. — The following table, compiled from 
results published by Bigelow and others,* shows the composition of 
various of the most common canned and preserved meats and meat 

* U. S. Dept. of Agric, Bur. of Chem., Bulletin 13, part 10. 



222 



FOOD INSPECTION AND ANALYSIS. 







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223 



products, and in one or two instances fresh meat has been included for 
^mparison. 
Sausages. — Nature and Composition. — Sausages are made from finely 
chopped meat, highly seasoned with various spices, and, as usually .sold, 
stuffed into casings made of the cleaned and prepared intestine-skin of 
cattle, sheep, or hogs. The meat most commonly used is pork. Sau- 
sages are frequently home-made, especially in farm communities, the 
chopped and .sea.soned meat being .stuffed in cloth bags instead of casings. 
Any and all kinds of meat are used in sausages, and much that is 
undesirable and even unwholesome, is undoubtedly most readily used up 
in this product. There is little doubt that horse meat occa.sionally gets 
into the hands of ihe marketmen to be worked up in the form of sausages 
mixed with other meat. The condition in respect to these matters has 
been greatly improved, however, by the increa.sed vigilance of State and 
Federal authorities. Sausages are .sometimes artificially colored, and in 
some cases contain so-called " fillers " in the nature of dried bread, corn 
meal, potato .starch, crackers, waste bi.scuit, boiled rice, etc. 

CHEMtCAL COMPOSITION OF SAUSAGES.* 





No. of 
Analy- 
ses. 


Ref- 
use. 


Water. 


Protein. 


Fat. 


Total 
Carbo- 
hy- 
drates. 


Ash. 




Kind. 


NX6.25 


Differ- 
ence. 


Fuel 

Value. 
Cals. 


Farmer: edible portion .. . 

as purchased 

Pork : as purchased 

Bologna: edible {xjrtion. . . 

as purchased 

Frankfort: as purchased. -- 


I 
I 
II 
8 
4 
8 


3-9 
3-3 


23-2 

22.2 

39-8 
60.0 

55-2 
57-2 


29.0 
27.9 
13.0 
18.7 
18.2 
19.6 


27.2 
26.2 
12.7 
18.4 
18.0 
19.7 


42.0 
40.4 
44-2 
17.6 
19.7 
18.6 


I.I 
0-3 

I.I 


7.6 

7-3 
2.2 

3-7 
3-8 
3-4 


2310 
2225 
2125 

109s 
I170 
1170 



• U. S. Dept of Agric, Off. of Exp. Stations, Bui. 28 (Revised Ed ). 

Adulteration of Sausages with Starchy Materials and Water. — 

Robi.son, who has made a special .study of these forms of adulteration at 
the Michigan Dairy and Food Department, .states as follows:* " Lean 
meat carefully chopped has an enormous combining power and can be 
made to take up a great quantity of water. Frankfurts, bologna, and 
fX)rk sausage have been found to be adulterated with from 0.5 to 5% of 
starch, indicating an addition of approximately i to 10% of so-called 
cereal (chiefly corn flour), and from 5 to 40% of water in addition to 



* Personal communication. 



2 24 ^'OOD INSPECTION AND ANALYSIS. 

that contained in the meats when in their fresh condition. The main 
excuse for the use of water is that it renders the meat of such a consistency 
that it may be easily stuffed into thin cases, such as are usually used for 
sausages that are eaten without removing the casing. As a matter of 
fact, this addition is not necessary where fresh meats are used, nor with 
those cuts of meat which the American public is in the habit of using in 
the manufacture of sausages in the home. Without doubt, in sausages 
composed of ox hearts, ears, snouts, lips, etc., in considerable quantities, 
the addition of water may facilitate the stuffing into thin casings. 

" Starch hastens and increases the absorbing or combining power of 
lean meat. In many instances where inferior products, such as ears, etc., 
are used, virtually it is the only absorbing agent present in the product. 
It then serves a two-fold purpose, first, giving an absorbing power to meat 
which it has not, or inflating the absorbing power of a meat which natur- 
ally is deficient in this respect, and second, acting as a skeleton or frame- 
work, thereby disguising shrinkage during the process of cooking. 
Generally, added water and cereal are evidences of inferiority, and they 
are by no means infrequently added with the very purpose of concealing 
such inferiority. 

" The evidence of adulteration with water is the discrepancy in the 
ratio of the water to the protein in the sausage. This ratio in sausage 
made from the fresh carcass varies from 3:1 to 3.6:1, being on an average 
about 3.35:1." 

Artificial Coloring Matter in Sausages. — Owing to the rapid color 
changes which freshly chopped meat, especially beef and mutton, natu- 
rally undergo, it is a common practice to employ powdered niter or salt- 
peter. Treated in this manner, meat remains pink, owing to the action 
on the haemoglobin of the oxides of nitrogen resulting from the nitrate. 
As much as 4 ounces of niter to 100 lbs. of meat is sometimes used. A 
larger quantity would result in a shriveled appearance. The use of 
artificial colors has been common in the past, in order to permanently dye 
the flesh a bright red, similar to the tint which the oxy-haemoglobin 
naturally imparts to the beef when fresh. A variety of colors have been 
employed for this purpose, such as red ocher, coal-tar dyes, cochineal, 
etc. They were sometimes used in admixture with preservatives. Their 
use has been largely discontinued in this country, owing to the enforcement 
of the regulations under the Federal meat inspeciton law. 



FLESH FOODS. 225 



ANALYTICAL METHODS. 



In analyzing meats and meat products due regard must be paid to 
their perishable nature, and, for this reason, immediately after their 
receipt by the analyst the various determinations should be promptly 
begun and rapidly carried out. If delays are absolutely necessary, the 
samples, as well as some of the solutions, especially during the earlier 
course of the analysis, should be kept on ice to prevent decomposition. 
Even at low temperatures, however, both bacterial and enzymic decom- 
position occur, and the nature of the proteins is slowly changed. Refuse 
material, such as bones, skin, gristle, tendons, etc., are separated as 
completely as possible by means of a knife from the edible portion, and thp 
latter, cut first into small pieces, is passed repeatedly through a sausage- 
machine or ordinary household meat-chopper, in order to reduce to a 
homogeneous, finely divided mass. 

Determination of Water. — From i to 3 grams of the finely divided 
material are weighed in a tared platinum dish, and dried to minimum 
weight at a temperature of 100° C. in an air-oven, A slight oxidation 
of the fat may introduce a trifling error, but, excepting for the most exact 
work, where the drying should be accomplished in an atmosphere of 
hydrogen, or in vacuo, the above method is sufficiently close. 

Determination of Water in Sausages. — Robison's Method. — A large 
sample (100 to 500 grams) is put through a food-chopper, weighed on a 
large porcelain plate, and allowed to dry at 70 to 90° C. A steam 
radiator may be conveniently used for this purpose. After drying 10 to 
12 hours, or over night, it is reweighed and finely ground in a small 
laboratory mill. If the sample is quite fat, the preliminary drying of the 
chopped meat may be carried out conveniently on a sieve, which will 
permit the fat to drain through onto a plate below, thereby making more 
simple and accurate the sampling and mixing. The fat thus removed 
should be separately weighed and dried. If the sample is quite lean, the 
final drying of 2 to 5 grams of the air-dried sample may be made at 100° 
C. in an ordinary water or electric oven. If it is quite fat, it is best to 
conduct this drying in a current of hydrogen. 

Determination of Ash. — The residue from the total solids is incinerated 
in the original dish over the free flame at a low red heat, or in a mufifle. 
It is usually advantageous, especially in the case of salt meat, to exhaust 
the charred sample with water, and collect the insoluble residue on a 
filter and ignite. The filtrate is then added, evaporated to dryness, and 



2 26 FOOD INSPECTION AND /IN A LYSIS. 

the whole heated to low redness and weighed. A perfectly white ash 
is difficult to obtain. 

Determination of Fat. — Extraction Method. — About two grams of 
the sample are carefully weighed in a tared Schleicher-and-Schiill Soxhlet 
shell, which, after drying in the air-oven at ioo°, is transferred to an 
extraction apparatus and subjected to continuous extraction for at least 
sixteen hours with anhydrous ether, or pure petroleum ether. It is 
impossible to extract all the fat in this manner, but the approximate 
result obtained is as a rule accepted, since complete extraction involves 
digestion of the nitrogenous matter with pepsin, and intermittent treatment 
with the solvent, a process both tedious and open to other sources of error. 
" More complete results may be obtained by pulverizing the extracted 
residue in a glazed porcelain dish with a glazed pestle, transferring again 
to the extraction shell, rinsing the dish with ether or petroleum ether, and 
again extracting. 

Kitd's Centrifugal Method.^ — Two and one-half grams of meat are 
treated in a Babcock milk flask with 8 cc. i:iH2S04 (or 5 grams with 
17 cc), and heated in a water bath to 60 to 70° with occasional agitation 
till the solution of the proteins is complete. One cc. of amyl alcohol is 
then added, and sufficient dilute H2SO4 to bring the layer of fat within 
the graduated scale. The tube is then whirled in a centrifuge for from 

3 to 5 minutes, and the amount of fat read on the scale. The amyl alcohol 
may sometimes be dispensed with, but is usually necessary for complete 
extraction and to obtain a clear layer of fat. 

Examination of Fat. — In case a special examination of the fat is to 
be made, a large portion of the original finely divided sample is shaken in a 
corked flask with petroleum ether boiling below 60°, and allowed to digest 
for some hours or over night. The solvent is then poured otY, the petro- 
leum ether removed as far as practicable by distillation, and last traces of 
the solvent removed by allowing the fat to stand in a vacuum desiccator 
over freshly ignited calcium chloride. In the case of mixed canned-meat 
preparations, it is often desirable to determine the character of the fats 
as a possible clue to the variety of meat used. For this purpose the 
regular methods prescribed under oils and fats (Chapter XIII) are used. 

Determination of Total Nitrogen. — Two grams of the sample are 
treated according to the Gunning or Kjeldahl method (page 69). While 
in the case of meat the time-honored custom of representing the total 
protein or nitrogenous substances by NX6.25 is by no means strictly 

* Arch. f. Hyg., 51, pp. 165-78. 



FLESH FOODS. 



227 



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2 28 FOOD INSPECTION /IND ANALYSIS. 

accurate, considering the wide variation in nitrogenous content of the 
various comjjounds present, a fairly close approximation to the total 
nitrogenous substance present is obtained by using this factor, since the 
proteins form by far the largest group of all. The factors to be employed 
in the cakiihition of the meat bases are given elsewhere (page 252). 

Separation and Examination of Nitrogenous Bodies. — Just how far the 
analyst should sulxlivide the various nitrogenous bodies present in meat 
de])en{ls largely on the nature of the case in hand. Frequently the 
simj^le determination of total nitrogen as above is sufficient. It is rarely 
necessary to go further than to divide the nitrogenous bodies into several 
main groups, according to their solubihty in water or other solvents, and 
their behavior toward certain reagents. 

The nitrogen may be determined separately in each of these classes, 
and by the ap|)roximate factor the corresponding nitrogen substance, or 
class of substances ascertained. 

In order to separate most comjjletely the various classes of nitrogenous 
bodies found in meat, a portion of the fat-free sample should first be 
exhausted with cold water, which removes the soluble proteins (soluble 
globulins, jjroleoses, and peptones) and meat bases, leaving behind the 
insoluble globulins, the sarcolemma, the albuminoids of the connective 
tissue (elastin, etc., also insoluble) and the collagen. By next exhausting 
with boiling water the collagen is removed in the form of soluble gelatin. 

By treatment of the combined aqueous extract with zinc sulphate, 
and with sodium chloride and tannic acid, as hereafter explained, the 
soluble proteins, including the peptones and gelatin, may be separated 
from the meat bases. 

In obtaining the results from which the table on page 222 was compiled, 
but three divisions of nitrogenous substances were made, viz., (i) those 
insoluble in hot water; (2) those precipitated from the water extract by 
bromine; and (3) the flesh bases. Owing to the incompleteness of the 
bromine precipitate, the figures given there for nitrogen precipitated by 
bromine are somewhat high, and those for nitrogen as meat bases are 
correspondingly low. This fact was observed during the progress of the 
work, and pointed out in the text with the statement that "considering the 
small amount of these bodies contained in meat, the results are believed 
to be a])pro.\imately correct." See also page 250. 

Determination of Nitrogenous Substances Insoluble in Water. — The 
sample is thoroughly extracted with cold water, the filter and insoluble 
material transferred to a flask, and nitrogen determined by the Gunning 



FLESH FOODS. 229 

or Kjcldahl method. The insoluble nitrogen thus obtained is multiplied 
by 6.25 to obtain insoluble proteins. It is obvious that the insoluble 
nitrogen may be obtained by difference, the cold water extract being 
fliluted to defmite volume, the nitrogen determined in an aliquot por- 
tion, and calculated to percentage of soluble nitrogen in the weight of 
original samj^le corresponding to the aliquot portion taken. The figure 
thus obtained, deducted from the percentage of total nitrogen, gives the 
percentage of insoluble nitrogen. 

Trowbridge and Grindley* digest the sample (thoroughly ground in 
a meat chopper) for one hour in ice water, in the jjroportion of 1000 grams 
of meat to 1500 cc. of water. The resulting solution is filtered through 
cheese cloth, the process being a.ssi.sted by squeezing the cloth and its 
contents with the hand. The residue is divided into .smaller portions, 
placefl in beakers, and washed in series, using fresh water with No. i only, 
and filtering through cheese cloth from one beaker to another until the 
last filtrate is colorless, neutral to phenolj>hthalein, and gives no reaction 
for proteins by the biuret test. The mixed filtrates and washings filter 
through paper readily, and give a clear red filtrate. 

Pennington! proceeds as follows with the meat of chickens: 
A portion of the finely divided red or white meat, weighing 60 grams, 
is put into a tall, slender bottle of 500 cc. capacity, constructed to fit a 
centrifuge capable of carrying i liter of material; 300 cc. of water are 
added, and the flask gently shaken for 15 minutes. The movement is 
merely .sufficient to keep the particles of meat in motion and the com {posi- 
tion of the extract homogeneous. Forcible shaking causes an emulsion 
to form, as does the very fine grinding of the ti.ssue. After shaking for the 
required length of time, the flask is rotated in an electric centrifuge for 
20 minutes, which causes the heavier particles to settle in a compact 
mass, and permits the decantation of the supernatant liquid, which is 
then filtered through paper. The extraction, as outlined, is repeated 
with portions of 300 cc. of water until the filtrate is practically protein 
free, as indicated by the biuret reaction. The attainment of this result 
recjuires ordinarily a volume of 1500 to 2500 cc. To guard against 
bacterial decomposition, thymol is added both to the flesh and to the 
extract, and to inhibit, so far as po-ssible, the action of the naturally 
occuring enzymes of the meat, the solution anrl the meat itself are kept 
cold, ice being used when necessary. 

* Jour. Am. Chem. Soc, 28, 1906, p. 472. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 115, p. 64. 



230 FOOD INSPECTION AND ANALYSIS. 

The extraction of the white meat is a much simpler operation than 
the extraction of the dark meat. The latter does not settle as compactly 
in centrifuging, filters more slowly, and persists in showing a distinct 
biuret reaction for a considerable time after the white meat is free of 
water-soluble proteins. In fact, certain fowls, more especially those 
which have been in cold storage for long periods of time, never show a 
dark meat entirely free from water-soluble nitrogen. In such cases, the 
question of the error due to long manipulation and enzyme action, involv- 
ing a rise in the actual quantity, has to be considered. It has been found 
by experiment that after long extraction of such tissue, a point is reached 
when a very faint biuret reaction, which does not apparently diminish, 
persists indefinitely. Such extractions are halted after about 26 hours, 
it being believed that a greater error would result in the gain of what 
has been originally insoluble material, than the loss of the preformed 
water-soluble nitrogen. The total extract of the muscle is made up to 
a definite volume, and neutralized to litmus paper with tenth-normal 
sodium hydroxide. 

Cook weighs 200 grams in a 450 Erlenmeyer flask, adds 250 cc. of 
water, and shakes for three hours in a shaking machine. The material is 
then filtered by means of linen bags, and extracted with water repeatedly 
by vigorous manipulation with the hands in successive portions of 
water, pressing out after each extraction until negative biuret reaction 
is obtained. The operation ordinarily requires from 2200 to 2500 cc. 
of water. A small quantity of phenol and thymol are added as pre- 
servatives. 

Weber* apphed Cook's method at room temperature and with ice 
water to samples of fresh and storage meat, as well as to samples which he 
had kept for varying lengths of time in the laboratory. He obtained a 
larger amount of soluble proteins when working at room temperature. 
No opinion was expressed as to whether this was due to the greater 
extracting power of water at room temperature, or to greater enzymic 
action during the period of extraction. 

Determination of Collagen. — The insoluble proteins obtained as 
directed above are transferred to a beaker, water added, and heated to 
boiling for some minutes. They are then separated by filtration and 
washed with boiling water. The nitrogen of the residue insoluble in 
boiling water is deducted from the nitrogen insoluble in cold water, and 
multipHed by 5.55 for the per cent of collagen. This method is of doubt- 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 42. 



FLBSH FOODS. 231 

ful value, owing to the difficulty of converting the collagen to soluble 
form on the one hand, and to the tendency to decompose a portion of 
the protein on the other. 

Determination of Coagulable Proteins. — The entire filtrate, or an 
aliquot portion thereof, from the determination of nitrogenous bodies 
insoluble in water is heated sufficiently to coagulate the coagulable pro- 
teins, filtered, the insoluble material washed with hot water, and the 
filter and contents transferred to a Kjeldahl flask and nitrogen determined 
by the Gunning method. The per cent of nitrogen multiplied by 6.25 
gives the per cent of coagulable proteins. 

The amount of heating necessary to obtain maximum coagulation 
varies with different materials. The Association of Official Agricultural 
Chemists directs that the solution be almost neutralized, but left still 
faintly acid, and boiled until the globulins are coagulated.* 

Pennington, t working with chickens, evaporates 350 cc. to a volume 
of about 100 cc. before filtering. Grindley and EmmettJ employ 
200 cc. of the solution, add alkali till neutral to litmus paper, and 
evaporate to 50 cc. In a later article, Trowbridge and Grindley § 
report maximum results from the cold water extract of fresh beef by 
neutrahzing one-fourth of the acidity to phenolphthalein before coagu- 
lation. 

Determination of Proteoses, Peptones, and Meat Bases. — The 
filtrate from coagulated proteins, having been diluted by wash water, is 
concentrated by evaporation and made up to 100 cc. Proteoses are then 
determined by Bumer's method (page 250), and meat bases by Sjerning's 
method, as modified by Bigelow and Cook (page 252). Peptones are 
determined by difference — the sum of the nitrogen occurring in insoluble 
nitrogenous bodies, coagulated proteins, meat bases and ammonia being 
deducted from the total nitrogen. 

Determination of Gelatin. — Modified Stutzer's Method.\\ — A weighed 
portion of the sample, say 10 grams, is thoroughly extracted by boihng 
water, the extract transferred to a porcelain dish containing about 20 
grams of previously ignited sand, and evaporated to dryness. The 
residue is then stirred with four successive portions of absolute alcohol, 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 108. 

t Ibid., Bui. 115. p. 65. 

t Jour. Am. Chem. Soc, 27, 1905, p. 665. 

§ Ibid, 28, 1906, p. 494. 

II U. S. Dept. of Agric, Bui. 13, part 10, p. 1397. 



232 FOOD INSPECTION /IND ANALYSIS. 

using about 50 cc. each time and pouring it off through a filter consist- 
ing of a layer of asbestos fiber on a perforated porcelain plate within a 
funnel. This funnel is surrounded by chopped ice, and is so arranged 
that gentle suction may be used to hasten the filtration. The residue is 
then repeatedly stirred with successive portions of about 100 cc. each of 
a mixture containing 100 cc. of 95% alcohol, 300 grams. of ice, and 600 
grams of cold water, the portions being passed through the asbestos filter, 
and the washing being continued till the solution is colorless as it comes 
from the filter, keeping the temperature always below 5°. The asbestos 
is then transferred to a beaker with the washed residue, and the whole 
thoroughly extracted with boiling water. The hot-water extract is evap- 
orated to small volume, and washed into a Kjeldahl flask, in which it is 
then evaporated to dryness, and the nitrogen determined by the Gunning 
method: N X 5.55 = gelatin. 

Detection of Nitrates. — A small portion of the finely divided mate- 
rial is treated in a porcelain dish or on a tile with a little 1% solution 
of diphenylamine in concentrated sulphuric acid. Presence of a blue 
color indicates nitrate. 

Detection of Preservatives. — -Meats may be systematically tested for 
preservatives in the same manner as canned goods. The preservatives most 
commonly used in meat and meat preparations are tested for as fol- 
lows : 

Detection of Sulphurous Acid. — Proceed as directed on page 834. 

Traces should be ignored, as slight reactions for sulphurous acid are 
obtained with meats that have not been chemically preserved. This 
is probably due to the decomposition of a portion of the proteins. 
According to Mentzel,* 4 milligrams per 100 grams may be due to this 
cause. 

Detection of Boric Acid. — A portion of the finely divided meat, mechan- 
ically freed from the fat as far as possible, is warmed with water acidified 
with hydrochloric acid, and turmeric-paper is soaked in the extract. The 
rose-red color of the turmeric-paper after drying (turned blue by weak 
alkali) is indicative of boric acid. 

A more delicate method of procedure consists in burning to an ash 
a portion of the meat, after treatment with lime water, and testing with 
turmeric tincture a solution of the ash slightly acidified with hydrochloric 
acid. 

* Zeits. Unters. Nahr. Genuss., ii, 1906, p. 320. 



FLESH FOODS. 233 

Detection of Salicylic Acid. — The sample, mechanically freed from 
fat, is slightly acidified and shaken out with ether. The ether extract 
evaporated to dryness is tested with a drop of a solution of ferric chloride. 
A deep-violet coloration indicates salicylic acid. 

Starch in Sausages, Meat-balls, tic — Detection. — The addition of 
cracker or bread crumbs is best indicated by the presence of considerable 
starch, which is readily recognized by the iodine test, applied by boiling 
up a portion of the sample with water, cooling and adding a drojj of 
iodine reagent to the liquid. The characteristic blue color is produced, 
if starch be present in notable quantity. Traces of starch may be due 
to the pepper and spices used in seasoning the sausage. A small admix- 
ture of starch is rendered apparent when a thin section of the sausage 
is treated with a drop of iodine reagent and viewed under the micro- 
scope. A microscopical examination will sometimes reveal the character 
of the starch, whether it is from cereals or from pepper, but in some 
preparations the starch is thoroughly cooked and its structure 
destroyed. 

Estimation of Starch. — The regular acid conversion process, p. 283, may 
be applied, but more accurate results are obtained by the method of 
inversion with malt extract. Medicus and Schwab * prepare the malt 
extract for this purpose by digesting 5 grams of ground malt with 50 cc. 
of water for one and one-half hours at 20° to 30° C. In making the 
starch estimation, they digest for two hours at a temperature of from 
40° to 50° C. 20 grams of the sausage mixed with 20 cc. of the malt 
extract, and afterwards for eighteen hours at room temperature. After 
filtering and washing, the filtrate is boiled to coagulate the albumin and 
again filtered. The second filtrate is then made up to 200 cc, 20 cc. of 
25% hydrochloric acid (specific gravity 1.125) are added, and the starch 
determined in the regular manner. 

Mayrhojer^s Method.-\ — This is considered the simplest and most 
reliable method of estimating the starch in such substances as sausages. 
From 60 to 80 grams of the sample are heated on the water-bath with 
an 8% solution of alcoholic potassium hydroxide, which, in the case of 
pure sausages, dissolves nearly ever\'thing except a little cellulose. To 
prevent gelatinization, warm alcohol is added to dilute the solution, 
which is then filtered through paper or asbestos. The starch is con- 

*Berichte d. chem. Gesell., XII, p. 1285. 

t Zeits. Nahr. Untersuch., 1896, p. 331; Abs. Analyst, 1897, p. 11. 



234 



FOOD INSPECTION /IND ANALYSIS. 



tained in the insoluble residue, which is washed with alcohol till the wash- 
ings are no longer alkaline, after which it is treated with an aqueous solu- 
tion of potassium hydroxide, and the starch solution made up to a definite 
volume. To an aliquot part of the solution 95% alcohol is added, where- 
upon the starch comes down as a flocculent precipitate. This is col- 
lected on a weighed filter, washed with alcohol and ether, dried, and 
weighed. The filter with its contents is then burnt to an ash, the amount 
of which is deducted. 

In order to avoid the ash determination, the starch may be precipitated 
from a weak acetic acid solution instead of from an alkahne solution, the 
potassium acetate formed being soluble in the alcohol, and nothing but 
pure starch is precipitated. 

Characteristics of Horse Flesh. — Although certain authorities have 
found distinguishing characteristics in color, consistency, odor, etc., between 
horse flesh on the one hand, and beef and pork on the other, it is extremely 
difficult, by its physical properties, to detect horse flesh when mixed with 
other meat, especially when the mixture is chopped. Horse flesh has a 
much coarser texture and is darker in color than beef. The muscle fibers 
are, as a rule, shorter in horse flesh. On treating horse flesh with formal- 
dehyde, Ehrlich * has found that a very characteristic odor is developed 
within forty-eight hours, suggestive of roasted goose flesh. 

Certain of the constants of the fat of horse meat differ from those of 
beef and pork, notably the iodine value and the refractometer readings. 
These constants are compared as follows: 



Iodine Value. 


Butyro-refractom- 

eter Readings. 
Temperature 40°. 




71-86 
38-46 
50-70 


53-7 
49.0 
48.6-51.2 


Beef fat 


Hog fat 





The fact that glycogen usually exists to a much larger extent in horse- 
flesh than in other meat, renders it possible in some cases to detect horse- 
flesh, when present in the mixture. 

The following table prepared by Bujard shows the relative amount of 
glycogen in various kinds of meat and sausages : 



* Zeit. Fleisch u. Milch Hyg., 1895, p. 232. 



FLESH FOODS. 



235 





Water. 


Glycogen Direct. 


Glycogen in Dried 
Substance. 




Niebel 
Method. 


- 

Mayrhofer 
Method. 


Niebel. 


Mayrhofer. 


Horse flesh 


74-44 

74.87 

76.17 

76.00 

69.26 

67.25 

74.6 

75-0 


0.440 
0.600 
1.827 
0.592 


0.445 

0.520 

1.727 

0.610 

0.038 

0.24 

0.086 

0.186 


1. 721 
2.388 
7-667 
2.466 


1. 741 
2.069 

7-247 
2 .542 




« 


« 


Red sausage (Knackwurst) 


0. 124 


Pork sausage 


0-733 
0.342 
0. 744 


Veal 


Pork 







In beef Bujard found 0.74 and 0.073 P^^ cent of glycogen calculated in 
terms of dried substance, and, in sausages made exclusively from horse 
meat, amounts of glycogen ranging from 0.05 to 5.34, the sample in the 
latter case being made from the liver. It was formerly thought possible 
to detect as small an amount as 5% of horse flesh in mixture, but later 
investigation showed that after the death of the animal, glycogen, though 
present at first in considerable quantity, decomposes more or less rapidly, 
going over into muscle sugar (dextrose). Hence, while the presence of 
much glycogen is suspicious, its absence is by no means proof that horse 
flesh was not used. 

Niebel did not consider the failure of the glycogen test as sufficiently 
conclusive to establish the absence of horse flesh, on account of the tendency 
toward decomposition of the glycogen. In the absence of starch, he 
regards the presence of more than 1% of dextrose in the fat-free meat, 
after conversion of the carbohydrates, to be proof of the presence of horse- 
flesh. 

Detection of Glycogen. — From the well-known color reaction produced 
by iodine on glycogen, horse flesh can often be detected, when present in 
sausages, unless obscured by the presence of starch or dextrin. 

Brautigam and Edelmann* proceed as follows: 50 grams of the finely 
divided meat are boiled with 200 cc. of water for an hour, and, after cool- 
ing, dilute nitric acid is added to the broth to precipitate the proteins 
and to decolorize. The broth is then filtered, and a portion of the filtrate 
is treated in a test-tube with a freshly prepared, saturated, aqueous solution 



* Pharm. Central., 1898, p. 557. 



236 FOOD INSPECTION AND ANALYSIS. 

of iodine, or, better, with a mixture of 2 parts iodine to 4 parts potassium 
iodide and 100 parts water, the reagent being carefully added so as not 
to mix with the broth, but form a layer above it. If glycogen be present 
in considerable amount, a wine-colored ring is observable at the junction 
of the two layers. On heating the test-tube, the coloration disappears 
if due to glycogen, but it reappears on cooling. This reaction was found 
to occur with horse flesh and not with beef, mutton, veal, or pork.* 

If the color is not clearly apparent, the chopped meat is heated on the 
water-bath with a solution of potassium hydroxide (using an amount of 
potassium hydroxide equivalent to 3% of the weight of the flesh) till the 
fiber is decomposed, after which the broth is concentrated to half its volume, 
treated with nitric acid to precipitate the proteins, filtered, and treated 
with the iodine solution as previously. 

Detennination of Glycogen.t — NiehcVs Modification of Brilcke's 
Method. — This method is applicable only in the absence of dextrose and 
dextrin. If therefore the presence and character of the starch indicates 
the presence to a considerable extent of cracker crumbs or other cereal 
"filler," the method is not accurate. 

A weighed portion of the flesh is heated on the water-bath with 3 to 4 
per cent of potassium hydroxide and four volumes of water for six hours. 
Evaporate the broth to half its original bulk, and add, after coohng, a 
solution of mercuric iodide in potassium iodide,J which precipitates the 
protein. Filter, and to the clear filtrate add 2| times its volume of 95% 
alcohol, collect the precipitated glycogen on a filter, wash first with 60% 
alcohol, then with 95% alcohol, then with absolute alcohol, then with 
ether, and finally with absolute alcohol. Dry at 115° C. and weigh. 

Landwehr^s Method. — Applicable in presence of dextrose. The broth 
prepared as in Niebel's method is freed from protein by the addition 
of zinc acetate. Filter, wash, and heat the entire filtrate on the water- 
bath with sufficient of a concentrated solution of ferric chloride, after- 
wards precipitating the iron with a few drops of a saturated solution of 
sodium hydroxide. Filter, wash the precipitate with hot water, and dis- 



* The reaction was found to occur also with the flesh of the human foetus and with the 
foetus of animals; also with mule meat, but not with the flesh of the dog or cat. 

t Jahresb. Nahr. Genuss., 1891, p. 38. 

X The reagent known as Briicke's reagent is prepared by precipitating a solution of mer- 
curic chloride with potassium iodide, washing the precipitated mercuric iodide till free from 
chloride, and afterwards saturating, while boiling, a 10% potassium iodide solution with the 
mercuric iodide. 



FLESH FOODS. 237 

solve in strong acetic acid- Add to the solution, after cooling, sufficient 
hydrochloric acid to produce a yellow color, then pour into 2\ volumes 
of alcohol, and proceed as in the preceding paragraph. 

Mayrhojer's Method * on which the results in the table on page 235 
are based, is as follows: Dissolve a weighed portion of the flesh in an 
aqueous solution of potassium hydroxide, precipitate the proteins by 
hydrochloric acid and Nessler's reagent, filter, and treat the clear filtrate 
with alcohol, which precipitates the glycogen. This is collected on a 
tared filter and washed, first with dilute alcohol, and finally with ether, 
dried at 110° C, and weighed. 

Pflilger and Nerking's Method.^ — Of the finely divided sample 50 grams 
are heated on the water-bath with 200 cc. of 2% potassium hydroxide 
till the solution is practically complete. After cooling, the solution is 
made up to 200 cc. with water, shaken, and filtered. To 100 cc. of the 
filtrate, 10 grams of potassium iodide and i gram potassium hydroxide 
are added, and the solution stirrred till clear, after which 50 cc. of 95% 
alcohol are added and the mixture allowed to stand over night. This 
precipitates the glycogen. Filter, and wash the precipitate with a solution 
made up of i cc. 70% potassium hydroxide, 10 grams potassium iodide, 
100 cc. water, and 50 cc. 95% alcohol. After further washing the glycogen 
with 2 parts strong alcohol and i part water, dissolve in water and by 
means of Briicke's mercuric-iodide-in-potassium-iodide reagent (see foot- 
note, p. 236) remove any remaining nitrogenous substances. Filter if 
turbid, and to the solution add common salt (about 2 milligrams per 100 cc. 
of solution), and reprecipitate the glycogen by adding 2 volumes of 95% 
alcohol. Filter, wash first with 95% alcohol containing a little common 
salt, then with absolute alcohol, and lastly with ether. Dry and weigh. 

Bigelow suggests that the glycogen as above obtained be converted 
by acid hydrolysis to dextrose, which is determined in the regular manner. 
Dextrose X .9 = glycogen. 

Identification of Raw Horse Flesh by the Blood Serum Test. J — This 
test depends upon the recent development of the principle that when a 
rabbit has been inoculated with the blood of a particular animal, as for 
instance that of the horse, the serum of the rabbit's blood will react with 

* Forsch. Ber., 1897, IV, 47. 

f Arch. ges. Physiol., 1899, 76, 531-542; Bui. 65, Bur. of Chem., p. 13. Recommended 
for Provis. Adoption by the A. O. A. C. 

X Schiitze, A., Ueber weitere Anwendungen der Pracipitine. (Deuts. med. Wochs., 
1902, No. 45, p. 804.) 

Wassermann, A., u. Schiitze, A., Ueber die Entwickelung der biologischen Methode 



2^3 



FOOD INSPECTION AND ANALYSIS. 



the blood of the horse and with that of no other animal. To prepare the 
blood serum for a reagent, inject a rabbit with lo cc. of defibrinated 
horse's blood every' day for five to six days, either subcutaneously or 
intravenously. The blood afterwards taken from the rabbit is clotted, 
and the filtered serum is used in making the test, or, if the reagent is to 
be kept for some time, the rabbit's blood serum is dried and an aqueous 
solution used for the reagent. 

If the clear expressed juice from the suspected flesh, filtered if necessary, 
be treated with a few drops of the rabbit's blood reagent, prepared as 
above, a cloudy precipitate will be produced in the case of horse flesh. 

By inoculating different rabbits in like manner with the blood of 
various animals, the flesh of the corresponding animals may be recognized 
from the reaction of the blood serum of the rabbit with its juices. Only 
raw flesh responds to the test, as heating destroys the virtue of the reagent. 

Determination of Muscle Sugar {Dextrose). — Boil a weighed quantity 
of the finely divided sample, say 50 grams, with water, add an excess of 
normal lead acetate solution, and make up with water to a given volume, 
say 250 cc. Filter, and to an aliquot part of the filtrate add enough of 
a saturated solution of sodium sulphate to precipitate the lead. Again 
filter, make up to a given volume, and determine the dextrose in a measured 
part of the solution by either of the regular methods. 

Detection of Coloring Matter.— i^e^/ Ocher is indicated by an excessive 
amount of iron in the ash. 

Cochineal is most readily tested for by the method of Klinger and 
Bujard.* The sausage, finely divided, is heated with two volumes of a 
mixture of equal parts of glycerin and water for several hours on the 
water-bath, the mixture being slightly acidified. The yellow solution 
is passed through a wet filter, and the coloring matter, if present, is pre- 
cipitated as a lake by adding alum and ammonia, the precipitate is filtered 
off and washed, after which it is dissolved in a small amount of tartaric 
acid, and the concentrated solution, contained in a test-tube, is examined 

zur Unterscheidung von menschlichem und tierischem Eiweissmittels Pracipitine. (Ibid., 

1902, No. 27, p. 483.) 

Wassermann, A., Ueber Agglutinine und Pracipitine. (Zeits. f. Hyg., etc., Bd. 42, 

1903, 2, p. 267.) 

Uhlenhuth, Die Unterscheidung des Fleischcs verschiedcncr Ticre mit Hilfe spezifische 
Sera und die praktische Anwendung der Methode in der P'leischbeschau. (Deuts. I\Ted. 
Wochs., 1901, No. 45, p. 780.) 

Miessner, H., u. Herbsl, Die Serum agglutination und ihre Bedeutung fiir die Fleis h- 
untertuchung. (Arch. f. wissensch. u. i)rakt. Tierheilk., 1902. Heft 3-4, p. 359.) 

* Zeit. angew. Chem., 1891, p. 515. 



FLESH FOODS. 239 

through the spectroscope for the characteristic absorption-bands of carmine 
lake, lying between h and D. 

Spaeth * has shown that both carmine (cochineal) and anilin red, 
which are the dyes most commonly used for coloring sausages, can be 
most readily extracted therefrom by warming the fmely divided material 
a short time on the water-bath with a 5% solution of sodium salicylate. 

Vegetable and Coal-tar Colors. — Various solvents are suggested for 
the removal of these dyes from sausage meat. Allen f recommends 
extraction with methylated spirit (a mixture of ethyl alcohol with 10% 
methyl) ; Bigelow | recommends heating with a mixture of 50% glycerin 
slightly acidified; A. S. Mitchell uses alcohol acidified with hydrochloric 
acid; Spaeth a 5% solution of salicylate of soda. Other solvents apjpli- 
cable in some cases are dilute ammonia and amyl alcohol. The solvent, 
after filtering, is evaporated to small volume, acidified with hydrochloric 
acid, and white wool is boiled in it. If the wool is distinctly dyed, a coal-tar 
color is undoubtedly present, and this can often be identified by methods 
given in Chapter XVII. According to Marpmann, pure normal flesh con- 
taining natural color only is completely decolorized by macerating for 
two hours in 50% alcohol, while artificially colored meat remains colored 
after this treatment. 

Marpmann's Microscopical Method.^ — Moisten a thin section of the 
sausage with 50% alcohol, and examine under the microscope. Some 
colors are readily apparent without further treatment. If only traces 
of color are present, clarify the substance by treatment with xylol, which 
is removed by the use of carbon tetrachloride. The mass rendered 
transparent by this treatment is then immersed in cedar oil and examined, 
the coloring matters, if present, being especially apparent. If the color 
used is fuchsin (magenta), carmine, logwood, or orchil, the substance 
of the cell will appear stained. If acid coal-tar dyes are used, the liquid 
contents of the cell will show the color. 

Detection of Frozen Meat. — Maljean || detects frozen meat by the 
aid of a microscope. A drop of the blood or meat juice is pressed out 
upon a slide and immediately examined before it sohdifies. Fresh meat 
juice contains many red blood corpuscles, floating in a clear colorless 
€erum, and readily apparent. In blood from frozen meat, the red cor- 

* Pharm. Central., 1897, 38, p. 884. 

t Commercial Organic Analysis, Vol. IV, p. 294. 

J U. S. Dept. of Agric, Bureau of Chemistry, Bui. 65, p. 16. 

§ Zeits. angewand. Mikrosk, 1895, p. 12. 

II Jour. Pharm. et Chem., 1892, XXV, p. 348. 



240 FOOD INSPECTION AND y4Ny4LYSIS. 

pusclcs are nearly always completely dissolved in the serum, due to freez- 
ing, or, if not dissolved, are much distorted and entirely decolorized, the 
liquid portion being darker than usual. 

Megascopically, the fresh meat juice is more abundant than that of 
frozen meat, and its color is deeper. According to C. A. Mitchell, if a 
small piece of meat once frozen be shaken in a test-tube v^^ith water, color 
is imparted to the water much more quickly than with fresh meat, and 
the color is deeper. 

MEAT EXTRACTS. 

Character and Composition. — Numerous preparations sold under the 
name of meat extracts have been on the market for many years. At th^" 
beginning of the nineteenth century the value of such extracts was known, 
but Liebig was the first some fifty years later to produce a commercial 
extract of meat. Liebig's preparation, as originally made, consisted 
of a cold-water extract of chopped lean meat, strained free from fiber, 
heated, filtered, and evaporated, thus containing little of any gelatin or pro- 
teins. Later, however, Liebig advocated the use of warm and even boiling 
water for extraction, by which method of preparation the amount of 
gelatin was greatly increased. He, however, condemned the use of salt. 

The best modern meat extracts consist for the most part of such por- 
tions of the meat, previously freed from bone and superfluous fat, as 
are soluble in water the temperature of which does not exceed 75° C. 
The widest latitude, however, prevails as to the temperature employed 
for the extraction, hence the character of the various j)roducts is some- 
what varied. It is not an uncommon practice to submit the meat to 
actual boiling with water, in which case the amount of gelatin will be 
considerable. In an extract prepared by warm water, one finds very 
little gelatin, more or less albumin, albumoses, and peptones, and prac- 
tically all the meat bases, phosphates, and chlorides present in the meat- 
also minute quantities of lactic acid, inosite, and possibly glycogen. By 
far the most important of these substances from the physiological stand- 
point are the meat bases — creatin, creatinin, xanthin, sarkin, etc. To 
the predominance of these amido-bodies is undoubtedly due the well- 
known stimulating effect of meat extracts. Indeed, a properly prepared 
extract has very little actual food value, but is rather to be regarded as 
a condiment or as a stimulant, acting on the nervous system in a some- 
what analogous manner to tea and coffee. 

Commercial meat extracts differ much in consistency according to 



FLESH FOODS. 241 

the extent to which evaporation is carried, varying from the thin fluid 
through the pasty form to the semi-soHd. Some preparations have added 
thereto finely ground dried beef or beef meal. 

Owing partly to unfounded claims of manufacturers, meat extracts 
are commonly confused with meat juices, and products belonging to the 
former class are sold for the latter. Considering the widely different 
nature of meat extracts and meat juices, such confusion is a serious matter. 
Meat extract is employed as a stimulant in the form of beef tea or as a 
flavor for soups. Meat juices, on the other hand, are employed in the 
sickroom as a readily available form of food. 

Standards. — ^The following standards for products of this class have 
been adopted by the Association of Official Agricultural Chemists and the 
Association of State and National Dairy and Food Departments: 

1. Meat extract is the product obtained by extracting fresh meat 
with boiling water, and concentrating the liquid portion by evaporation 
after the removal of fat, and contains not less than 75% of total solids, of 
which not over 27% is ash, and not over 12% is sodium chloride 
(calculated from the total chlorine present), not over 0.6% is fat, and 
not less than 8% is *nitrogen. The nitrogenous compounds contain 
not less than 40% of meat bases, and not less than 10% of creatin and 
creatinin. 

2. Fluid meat extract is identical with meat extract, except that it 
is concentrated to a lower degree, and contains not more than 75, and not 
less than 50 >< of total solids. 

3. Bone extract is the product obtained by extracting fresh trimmed 
bones with boiling water and concentrating the liquid portion by evapo- 
ration after removal of fat, and contains not less than 75% of total solids. 

4. Fluid bone extract is identical with bone extract, except that it is 
concentrated to a lower degree and contains not more than 75 and not 
less than 5o';4 of total solids. 

5. Meat juice is the fluid portion of muscle fiber, obtained by pressure 
or otherwise, and may be concentrated by evaporation at a temperature 
below the coagulating point of the soluble proteins. The solids contain 
not more than i59r of ash, not more than 2.5% of sodium chloride (calcu- 
lated from the total chlorine j)resent), not more than 4 nor less than 2% 
of phosphoric acid (P20^), and not less than 12% of nitrogen. The 
nitrogenous bodies contain not less than 35% of coagulable proteins, and 
not more than 40% of meat bases. 

6. Peptones are products j)repared by the digestion of protein material 



242 



FOOD INSPECTION AND ANALYSIS. 



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244 I'OOD INSPECTION AND ANALYSIS. 

by means of enzymes or otherwise, and contain not less than 90% of 
proteoses and pei)tones. 

7. Gelatin {edible gelatin) is a purified, dried, inodorous i)roduct of 
the hydrolysis, by treatment with boiling water, of certain tissues, as skin, 
ligaments, and bones, from sound animals, and contains not more than 
2% of ash and nol less than i $'%, of nitrogen. 

ANALYSES OF MEAT EXTRACTS.— Largely by the ai)i)licati()n of the 
above standards, Bigelow and Cook* have classified a number of j)roducts 
of this class as solid (pasty) meat extracts, fluid meat extracts, and " mis- 
cellaneous pre])arations." 

Their results are given on pages 242, 243, 247, and 248. 

Solid and Fluid Meat Extracts.— It will be noted that the solid 
and lluid extracts are idenlical, except that the latter are concentrated only 
half as much as the former. AUenf holds that the maximum chlorine 
content of meat extract calculated to sodium chloride is 0.06% for every 
unit of dry solid matter, and that excess over that amount is due to added 
common salt. This opinion is based on the comj)Osition of South Ameri- 
can extracts j)rei)are(l from the meat of the entire carcass. Streett con- 
siders that the maximum standard of 12% is too high, and encourages 
the manufacturer to add salt to his product. In this country, however, 
extracts are commonly prepared in i)art by the evaj)oration of the soup 
li(|Uor in which meat is j)arboiled before canning,^ and in part from trim- 
mings. It is claimed that the natural salt content of the product made 
in this manner is higher than when the entire meat of the carcass is 
employed. A second grade article is also made from bones, trimmings, 
etc., and contains a still higher i)ercentage of sodium chloride. This 
product is designated as "bone extract" in the standards given on i)age 241 . 

The ])resence of an excessive amount of sodium chloride is usually 
due, i)robably, to the i)resence of the ]:>roduct last mentioned, or to the 
use of corned beef in the preparation of the substance. In the latter 
case nitrates are generally present. On comj)aring the analyses given 
above with the com])osilion of other products of this class, as contained 
in the following tables, the value of the i)ercentage of meat bases, es- 
pecially of creatin and creatinin, in distinguishing meat extracts from 
meat juices and manufactured products of that general type is apparent. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 114. 
t Commercial Organic .\nalysis, vol. 4, p. 307. 
X Conn. Expt. Station, Report for 1907 and 1908, p. 622. 

§ Bigelow and Cook, U. S. Dept. of Agric, Bur. of Chem. Bui. 13, pt. 10, p. 1389. 
Bigelow and Cook, U. S. Dept. of Agric, Bur. of Chem., Bui. 114, p. 13. 



HLESH HOODS. 



245 



Meat Juices Prepared in the Laboratory. For the jjur{jo.sc of 
comparison with meat extracts, the following analyses of meat juices 
fjreparefl in the lahoratorv are of interest. 

MKAT JCICKS I'kl.I'AkKI) IN LAIiOKATORV'.* 



Prepiraticn of Juice. 



Composition of Sample. 



Water 

in 
Juice. 



Ash. 



Chlorine 
as 

Sodium 
Chloride 

in Ash. 



Phos- 
phoric 
Acid 
(PzOs). 



Ether 
Extract. 



Acidity 

as 
Lactic 
Acid. 



Round beef, cold pressed 

Chuck Vjeef, cold pressed 

Round beef pressed at 60" C 

Chuck beef pressed at 60° C 

Juice from beef chuck at 60° C 

Juice pressed from sirloin steak and water. . 
Juice extracted from sirloin steak by cold 

pressure 

Juice extracted from beef chuck by cold 

pressure 

Juice extracted from beef chuck by cold 

pressure after 6 hours at 60'- 100° C. 



8s . 76 
86.8s 

90. 6 s 
9 1 . 9c 
89 . 56 

91 . 10 

96. 13 
96. s8 
98.11 



' • .53 
; ,86 
I . 36 
I . 29 
I .27 
I .40 

o. 46 

0.43 

0.39 



015 
o, 19 
0.16 
0.12 



0.0s 
0.0s 
COS 



0.37 
0-31 
0.36 
0.29 
0.37 
o, 18 

o. 14 

O. I I 
O. 12 



0.27 
0.30 

o. r9 
0.64 



Preparation of Juice. 



Composition of Sample. 



Total 
Nitro- 
gen. 



Round beef, cold pressed 2 ,08 

Chuck Vjeef. cold pressed 1.74 

Round beef pressed at 60° C, .^_ . , , , ,,..,.( r . 16 

Chuck beef pressed at 60' C 1 t . 09 

Juice from hieef chuck at 60" C i ,09 

Juice pressed from sirloin steak and water. . i . 18 
luice extracted from sirloin steak by cold 

pressure o . 48 

Juice extracted from beef chuck by cold 

pressure o . 43 

Juice extracted from beef chuck by cold 

pressure after 6 hours at 6o'^-ioo° C 1 0.24 



In.solu- 

ble 
Nitro- 
gen. 



Coag- 
ulabie 
Nitro- 
gen. 



0.16 I 1.37 
0.29 I 0.98 

0.68 
0.12 I 0.41 

0.49 

OS4 

0.34 
0.34 
0.00 



Pro- 
teose 
Nitro- 
gen. 



.06 

• 07 
.04 

• 07 



trace 
trace 



Pep- 
tone 
Nitro- 
gen 



0.16 



o. 18 
none 
none 
o. 12 



Amido 
Nitro- 
gen. 



.3.? 
.29 
■ 43 
• 27 
.18 
.26 



0.09 
0.08 



Unde- 
ter- 
mined 
Matter. 



0.47 
I .03 
1 .90 
0.40 
2 . 92 
0.94 

0.85 

O.S9 

0.2s 



Preparation of Juice. 



Results in Terms of Total 
Nitrogen. 



Insol-[ Coag- 
uble ulablc 
Pro- Pro- 
tein, tein. 



Round beef, cold pressed 7.69 6s. 87 

Chuck hieef, cold pressed 16.66 S^-32 

Round beef pressed at 60° C. . . s8 • 62 

Chuck beef pressed at 60° C. . . 
Juice from beef chuck at 60'^ C. 
Juice pressed from sirloin steak 

and water 

Juice extracted from sirloin 

steak by cold pressure 

Juice extractci from beef 

chuck by cold pressure 

Juice extracted from beef 

chuck by cold pressure after 

6 hours at 6o°-ioo'' C 



I r . o 1 1 37.61 
44. 95 



4576 
70.83 



Albu- 
moses 



2.88 
4.02 
3.45 
6.42 
38.53 

16.9s 



Pep- 
tones. 



7.69 
6.32 
0.86 
19.26 



Amido 
Bodies 



15.87 
16.66 
37-07 
24.77 
16. 51 

22 .03 

29. 17 

20 93 



Nitrogenous Bodies. 



Insol- Coag- 
uble ulablc 
Pro- Pro- 
tein, tein. 


Pro- 
teoses. 


Pep- 
tones. 


1.00 8.s6 
1. 81 6.13 

4.2s 

0.7SI 2.56 

3.06 


0.38 
0.44 
0.2s 
0.44 
2.63 


1.00 
0.69 
0.06 
1.31 


?.38 


I.2S 


I .'3 


2. >3 


trace 


1 
none 


2,13 


trace 


none 


0.00 


trace 


0.7s 



Amido 
Bodies 



'.03 
o. 90 



.84 
■S6 



0.44 
0.2S 



• Bigelow and Cook, U. S. Dept. of Agric. Bui. 114, p. 19. 



246 FOOD INSTECTION AND ANALYSIS. 

The composition of these products is widely different from that of 
the so-called meat juices of commerce, as given in the table on page 247. 
It appears to be impracticable to so preserve a true meat juice that it 
can become an article of commerce. 

Miscellaneous Meat Preparations. — There is on the market a wide 
variety of manufactured products intended to replace beef juice. Some 
of these have meat extract as a base, and some have an addition of a small 
amount of albumin, or some form of soluble protein. Others consist 
largely of albumoses and peptones, and are formed by the action of steam 
or of acid and pepsin on meat. The tables on pages 247 and 248 give 
the composition of a number of products of this nature. 

The preparations given in the table on page 248 are arranged in four 
classes, according to their content of proteoses and peptones, meat bases, 
creatin, and insoluble proteins. 

Yeast Extract. — During recent years a product closely resembling 
meat extract has been prepared by the evaporation of the water extract 
of yeast. This product has been sold as a substitute for meat extract 
and has been reported in Germany as an adulterant therefor. The best 
means of distinguishing yeast extract from meat extract is by the deter- 
mination of creatin and creatinin, which are absent in the former.* 

Wintgenf has pointed out that the filtrate from the zinc sulphate 
precipitate obtained in the determination of albumoses is clear in the 
case of meat extracts, but turbid if a considerable percentage of yeast 
extract be present. 

METHODS OF ANALYSIS. 

Water. — Water is best estimated by weighing from 2 to 3 grams of 
the preparation (if of the dry or pasty variety), or from 5 to 10 grams of 
the fluid extract, into a large platinum dish, the dry variety being dissolved 
in a little hot water. The powdered preparations are dried directly 
without admixture. To pasty and fluid preparations are added sufficient 
ignited asbestos, pumice stone or sand, sifted free from dust, to absorb 
the solution. Pasty preparations are first dissolved in sufficient water to 
make them distincdy fluid. The sample is then dried at 100° C. till it 
ceases to lose weight. Tin or lead dishes or Hoflfmeister glass dishes 
may be employed, and after being cut or broken, placed in the extraction 
tube for the determination of fat. 



* Micko, Zeits. Unters. Nahr. Genuss., 5, 1902, p. 193; 6, 1903, p. 781. 
,t Arch. Pharm., 242, 1904, p. 537. 



FLESH FOODS. 



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FOOD INSPECTION AND ANALYSIS. 



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FLESH FOODS. ?49 

Ash. — From 2 to 3 grams of a fluid jjreparation, or a corresponding! v 
less amount of a pasty jjreimration, are evaporated to dryness in a flat- 
bottom dish. Pasty preparations should first be dissolved in water, in 
order that the sample may distribute itself evenly over the bottom of the 
dish. The substance is then charred at the lowest possible heat, the 
charred mass exhausted with water, the insokible residue collected on a 
filter and washed. The filtrate and residue are then returned to the 
dish and completely incinerated, the soluble jjortion of the ash added, 
evaporated to dryness, heated to a low redness and weighed. Chlorine 
is determined volumetrically or gravimetrically in the solution of the ash. 

Fat. — This is best obtained by extracting a portion of the air-dried 
substance with petroleum ether in a Soxhlet ajjparatus. Petroleum 
ether extracts the fat only, while ether extracts other substances as well. 

The determination is usually made in the residue from the determina- 
tion of water. A properly prepared extract has very little fat. 

Total Nitrogen. — The extract should be tested for nitrates, and the 
i;ro{jer modification of the Gunning method should be employed, rlepend- 
ing on the presence or absence of nitrates. Use from i to 5 grams for the 
determination. Xitrates should be properly accounted for. 

Separation of Nitrogenous Compounds. — To correctly gauge the food 
value of a meat extract, it is essential to separate and estimate at least 
roughly its principal nitrogenous components. To attempt to make such 
a separation with a high degree of accuracy would involve a long and 
tedious series of operations, which in most cases w^ould be impracticable. 
Usually the separation into three main groups is sufllcient, insoluble 
proteins, tannin-salt preci[jitate (proteoses, peptones and gelatin) and 
meat bases. At times, however, it may become necessary, or at least desir- 
able for specific purposes, to determine certain of the nitrogenous com- 
pounds separately. 

Various quick methods have often been employed in connection with 
technical operations to determine the approximate amount of the several 
nitrogenous boriies or groups, but they have been generally discarrled as 
untrustworthy. Among these may be mentioned Bruylant's* method of 
fractional precipitation by varying strengths of alcohol, and Hehner'sf 
method of precipitation by methylated spirits. .Another method that 
was widely used for a time was that of Allen and Searle,| which is based 

* Jour. Pharm. et Chem., 5, 1897, p. 515. 

t Analyst, 10, p. 221. 

X Analyst, 22, 1897, p. 259. 



2 50 FOOD INSPECTION AND /IN A LYSIS. 



i 



on the belief that proteoses and peptones were completely precipitated 
from aqueous solution by saturating with bromine, after acidifying with 
hydrochloric acid. The experimental evidence on which this method 
was based consisted of the precipitation of proteins from the filtrate from 
the zinc sulphate precipitate, diluted with an equal volume of water. 
From the results so obtained, it api)eared that j)e])tones and proteins of 
larger molecule were completely precipitated by bromine in a half satur- 
ated solution of zinc sulphate, and it was assumed that precipitation 
from aqueous solution would be equally complete. Owing to a lack of 
methods by which peptones could be completely precipitated, this method 
has been widely used. The use of the method now appears to have been 
largely discontinued, as it has been repeatedly found to be unreliable.* 

Complete Separation of Nitrogen Compounds would involve a discrimi- 
nation between meat fiber and insoluble i)rotein, coagulable proteins, acid 
albumin (synlonin),albumoses, peptones, meat bases, gelatin and ammonia. 

(i) Insoluble Proteins. — About 5 grams of the extract of the dry, or 
20 to 25 grams of the fluid variety are exhausted with 200 to 250 cc. water 
at about 20° C, and the residue collected on a tared filter. It is often 
difiucull to filter such an extract in the ordinary way, and the use of the 
centrifuge is heli)ful, passing the clear supernatant liquid through the 
filter, and finally washing the residue thereon. The residue is washed, 
dried at 100°, and weighed, or the nitrogen may be determined by the 
Gunning method. The sample may also be placed in a graduated flask, 
digested in a considerable amount of cold water for several hours with 
frequent shaking, and the nitrogen determined in an aliquot part of the 
filtrate. This deducted from total nitrogen gives the nitrogen of insol- 
uble proteins. Nx6.25=total insoluble matter, which includes, besides 
the meat fiber, the insoluble proteins. 

(2) Coagulable Proteins. — The filtrate from (i) is neutralized exactly 
to litmus, and dilute acetic acid added till acidity is just apparent. It 
is then boiled for some minutes to make insoluble the coagulable proteins, 
which are collected upon a filter (using to advantage a centrifuge as in 
the preceding paragraph). Determine the nitrogen in the washed residue, 
using the factor 6,25 for coagulable protein. 

(3) Albumoses or Proteoses. -^ — An aliquot part of the filtrate from (2) 



* Bigelow, U. S. Dept. of Agric, Div. of Chem., Bui. 13, pt. 10, p. I3g6; Bui. 81, 
p. 106. Sjerning, Zeits. anal. Chem., 39, 1900, p. 545. Fraps and Bizzell, Jour. Am. 
Chem. Soc, 22, 1900, p. 709. Van Slyke, Chem. News, 88, 1903, p. 92. 

t Bomer, Zeit. anal. Chem. 5, 1895, p. 562. 



FLESH FOODS. 251 

is saturated with zinc sulphate, adding the powdered sah as long as it 
continues to dissolve with stirring and shaking. Proteoses and any 
traces of gelatin or insoluble proteins that have escaped removal are 
j)recij)itated, but not the peptones or meat bases. Filter, wash, and 
determine the nitrogen in the residue, using the factor 6.25 for the proteoses. 

(4) Peptones. — Sjernmg's Tannin-salt Method, modified by Bigelow 
and Cook.* — An aliquot part of the filtrate from (2), concentrated by 
evaporation to 20 cc. or less, in case it is necessary to take more than 20 
cc, is transferred to a loo-cc. flask. 

Then 50 cc. of a solution containing 30 grams of sodium chloride per 
100 cc. are added, and the flask agitated to insure the thorough mixing 
of its contents and the solution of the sample. The flask is now placed 
in the ice box at approximately 12° C. After the solution has reached 
the ice box temperature (this requires an hour usually), 30 cc. of a 24% 
solution of tannin (which must be at ice box temperature) are added. 
The total volume is now 100 cc. The contents of the flask are thoroughly 
mixed, and the flask returned to the ice box, where it remains over night. 
In the morning the solution is filtered at ice box temperature into a 50 cc. 
graduated flask. The nitrogen is determined in this filtrate, and also 
in an aliquot portion of the filtrate from a blank, in which the reagents 
alone are employed. The nitrogen found in the 50 cc. portion, multiplied 
by two (after correction for the nitrogen in the blank), gives the total 
nitrogen in the filtrate, and is calculated to per cent of nitrogen on the 
sample employed. This includes the nitrogen present as ammonia, and 
all of the nitrogen of the meat bases, except that portion of the creatin 
precipitated by the tannin-salt reagent. The figure thus obtained is added 
to the per cent of nitrogen as determined in (i), (2), and (3). This sum, 
deducted from the total nitrogen, is ordinarily reported as the per cent 
of nitrogen existing as peptones, and is multiplied by 6.25 for the per cent 
of j)eptones. 

It is probable that the substances so reported are not true peptones, 
since the filtrate from (3) commonly gives no biuret reaction. They 
probably consist largely of peptoids, formed by the action of the hot solu- 
tion on gelatin and polypeptides. 

Bigelow and Cook find that the tannin-salt precipitate is not contam- 
inated with other meat bases than creatin. They believe that about 
one-quarter of the creatin is found in this precipitate. Accordingly, 

* Jour. Am. Chem. Soc, 28, 1906, p. 1496. 



252 FOOD INSPECTION AND ANALYSIS 

they suggest that the percentage of crcatin be determined before and 
after precipitation with tannin-sah reagent, and correction made by the 
results so obtained. 

Street beheves this correction to be impracticable. He finds that it 
is very difficult, if not impossible, to remove tannin completely from the 
filtrate, and that the slightest trace of tannin prevents the color reaction 
for creatin. 

(5) Meat bases. — The per cent of nitrogen found in the filtrate from 
the tannin-salt precipitate in (4) , after deducting the per cent of nitrogen 
found as ammonia in (6), is multiplied by 3.12 to obtain the per cent of 
meat bases. 

(6) Ammonia. — From 5 to 10 grams of the original sample are dissolved 
in a convenient volume of water, and distilled after the addition of powdered 
magnesia. The distillate is titrated, and its alkalinity reported as per cent 
of NH3. The corresponding percentage of nitrogen is also calculated, 
as it is necessary for the calculation of meat bases in (5). 

Determination of Creatin and Creatinin.* — This determination may 
be made in an aliquot of the filtrate from the insoluble and coagulable 
protein determination.! The aliquot must contain sufficient total creatinin, 
after dehydration of the creatin to creatinin, to give a reading not far 
from 8° on the scale of the Dubosc colorimeter, after applying the colori- 
metric method as outlined by FolinJ for the estimation of creatinin in 
the urine. Heat this aliquot with 5 cc. of half-normal hydrochloric acid 
for three and a half hours on a steam bath under a reflux condenser. 
Neutralize the hydrochloric acid by the addition of 5 cc. of half-normal 
sodium hydroxide, then add 15 cc. of a saturated picric acid solution, 
and 5 cc. of 10% sodium hydroxid. Shake the solution, and allow it to 
stand fo^ five minutes; make up to 500 cc, and compare the color with 
a half-normal solution of potassium bichromate in the Dubosc colorimeter. 
The half-normal bichromate solution when the scale is set at 8° corresponds 
to 10 mg. of creatinin, and from this figure the amount of creatinin in the 
aliquot is readily calculated. 

Hehner§ criticises this method as apphed to meat extracts. He believes j 
that more complete results may be obtained by using 25 cc. of a 1.01% of 
picric acid with " a quite small amount of alkali." He considers the 



* Bigelow and Cook, Jour. Am. Chem. Soc, 28, 1906, p. 1497. 

t Aliquot should represent approximately 0.2 gram of a first class solid beef extract. 

J Zeits. physiol. Chem., 41, 1904, p. 223. 

§ Pharm. Jour., 78, 1907, p. 683. 



FLESH FOODS. 253 

precipitate somewhat soluble in excess of alkali. Emmctt and Grindley* 
have made an exhaustive study of the method as applied to meats, meat 
extracts, and urines. They find that 15 cc. of 1.2% picric acid should be 
employed for the original creatinin determinations, and 30 cc. for the 
dehydrated creatinin. They also recommend 5 cc. of alkali for the 
original creatinin, and 10 cc. for the dehydrated creatinin, though an 
additional 5 cc. does not give lower results. 

Determination of Xanthin Bases.— In addition to creatin and creatinin, 
a true meat extract or meat juice should contain small amounts of xanthin 
bases, including xanthin, hypo-xanthin, guanin, and adenin. These 
bodies are derived from the nuclei of the cells, and, consequently, in an 
extract that is prepared from fresh, unaltered beef a certain amount of 
these bodies should be obtained, together with the salts and other extractive 
matter. The determination of the xanthin bases is, therefore, of value 
in determining the origin of an alleged extract of meat. 

The xanthin base figures in the tables show a variety of results, which 
is explained by the fact that in the preparation of the extract under certain 
conditions of heat and pressure some of these bodies are destroyed. The 
followinrg method was employed for their determination: 

Schittenhelm' s Method modified by Cook.\ — Use an amount of the stand- 
ard solution equivalent to 5 grams of the original extract. Place in a 
large evaporating dish, and add 500 cc. of 1% sulphuric acid. Evaporate 
to 100 cc. within 4 to 5 hours. Cool, and neutralize with sodium hydroxide. 
Add 10 cc. of 15% sodium bisulphate, and 15 cc. of 20% copper sulphate; 
allow this to stand over night, filter, and wash. The precipitate suspended 
in water is treated with sodium sulphide, and warmed on the steam bath. 
Add acetic acid to acidify, and filter hot. To the filtrate add 10 cc. of 
10% hydrochloric acid, and evaporate to a volume of about 10 cc. Filter, 
make ammoniacal, and add ammoniacal silver nitrate of 3% strength. 
After standing several hours, the solution is filtered and the precipitate 
washed with distilled water until no longer alkaline. The nitrogen in 
the precipitate is that of the xanthin bases. 

Determination of Gelatin. — This is accomplished by the modified 
Stutzer method as given on page 231. 

Determination of Acidity .J — In the average solid or pasty extract the 
lactic acid content varies from 4 to 8 per cent, and, as a rule, the extract 
showing the highest phosphoric acid content likewise shows the highest 

* Jour. Biol. Chem., 3, 1907, p. 491. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 114, p. 41. 

X Ibid., p. 39. 



1 



2 54 FOOD INSPECTION AND /IN A LYSIS. 



acidity. This is undoubtedly due to the fact that some of the phos- 
phoric acid is in the form of di-hydrogen or acid phosphate, although 
the character of the acidity has not been definitely determined. 

The method employed for determining acidity consisted in adding 
tenth-normal sodium hydroxide to a dilute solution of the meat extract in 
water, until a droj) removed by means of a small capillary tube and tested 
on a piece of litmus pai)er gives a neutral reaction. The results are 
expressed in cubic centimeters of tenth-normal sodium hydroxide, also 
as per cent of lactic acid present. The acidity is commonly expressed as 
per cent of lactic acid, though it is probably due in large part to acid 
potassium phosphates. Lactic acid is the chief organic acid, though 
succinic acid is also ])resent in notable amount.* 

Detection of Preservatives in Meat Extracts. — Boric acid is some- 
times used as a ])reservative in these j)reparations, and is tested for by 
the usual methods (Chai)ler XVIII). 

Determination of Glycerin. — This substance is sometimes used as 
a preservative for iluid prejjarations. Perhaj)S the most satisfactory 
method that has been suggested for its determination is that of Bigelow 
and Cook.f The dried residue is extracted with acetone, the meat bases 
removed by precipitation with silver nitrate, followed by phosphotungstic 
aoid. The glycerin is determined in the filtrate by Hehner's method. J 

FISH. 
Structure and Composition. — Fish resembles meat both structurally 
and in the nature of its constituents, but differs from it in a marked degree 
in the relative proportions of its various components. Thus, there is 
considerably more refuse matter such as skin and bones in fish than in 
meal, and in the edible jjortion of fish the amount of water is much greater. 
Comparing the nitrogenous components of each, we find in fish more 
of the gelatin-yielding matter (collagen) and less of the extractives than 
in meat. There is much less haemoglobin or allied coloring substance 
in the flesh and blood of fish than in meat, which accounts for the white color 
usually characteristic of the former. Certain fish, however, like the salmon, 
probably owe their distinctive color to a pigment belonging to the lipo- 
chromc§ class. The mineral content of fish, as a rule, exceeds that ol 
meat and contains more phosphates. The various edible fishes differ 
less among themselves in composition than do the meats. According to 
Chapman the average comf)osition of fish is as follows, in parts per looo: 

* Arb. kais. Gcsun(thcilsamt, 1906, vol. 24. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 114, p. 42. 

% Jour. Soc. Chem. Ind., 8, 1889, p. 4. 

§ A series of fatty animal pigments. 



FLESH FOODS. 



255 



Water 740 . 82 

Albumin 137 .40 

Collagen 43-88 

Fat 45.97 

Extractives 16.97 

Salts 14.96 

Hutchison classifies fish as follows with reference to their content of fat: 

Lean. — Fish having less than 2% fat, such as cod and haddock. 

Medium. — Fish having 2 to 5% fat, such as halibut and mackerel. 

Fai. — Fish having more than 5% of fat, such as eel, 18%; salmon, 12%; 
turbot, 12%, and herring, 8%. 

According to At water and Bryant * the composition of different varie- 
ties of fish is as follows: 

COMPOSITION OF FISH. 



Refuse. 



Water. 



Protein. 



NX 
6.25. 



By 
Di.Ter 
ence. 



Fat. 



Ash. 



Fuel 
Value 

per 
Pound. 



Bass — 
Bluefish— 
Cod— 
Eel- 
Haddock— 
Halibut- 
Herring — 
Mackerel- 
Perch — 
Pickerel — ■ 
Salmon — 
Shad- 
Skate — 
Smelt — 
Trout — 
Turbot — 
Whitefish- 



55-0 
48!6 



51.0 

17-7 
42.6 



44.7 



edible portion 

as purchased 

edible jjortion 

as purchased 

edible portion 

as j)urchased j 52.5 

edible portion 

as purchased 20 

edible portion 

as {)urchased 

edible jjortion 

as purchased 

edible j)ortion 

as purchased 

-edible portion 

as purchased 

edible portion 

as purchased | 62 . 5 

edilile portirjn ! 

as purchased 

edible portion 

as [jurchascfl 

edible portion 

as purchased 

edible portion 

as purchased 

edible portion 

as purchased 

etlible jjortion 

as purchased 

edible |>ortion 

as purchased 

-edible portion 

as Durchased 



47-1 



34-9 
50-1 
51.0 



41.9 
48.1 



47-7 



53-5 



77-7 
35-1 
78-5 
40-3 
82.6 

38-7 
71.6 

57-2 
81.7 
40.0 

75-4 
61.9 

72-5 
41-7 
73-4 
40.4 

75-7 
28.4 

79-8 
42.2 
64.6 
40.9 
70.6 
35-2 
82.2 
40.2 
79-2 
46.1 
77-8 
40-4 
71.4 

37-3 
69.8 

32.5 



2.8 

1 .1 

1 .2 
0.6 
0.4 
0.2 
9.1 
7-2 
0-3 
0.2 

5-2 

4-4 
7-1 
3-9 
7-1 
4.2 
4.0 
1-5 
0-5 
0-3 
12.8 
8.9 

9-5 
4-8 



i.i 
1414 
7-5 
6-5 
3-0 



1 .2 
0-5 
1-3 
0.7 
1 .2 
0.6 
i.o 



1.2 
0.6 

1.0 
0.9 

1-5 
0.9 
1.2 
0.7 
1.2 
0.4 
I.I 
0.6 

1-4 
0.9 

1-3 
0.7 
I.I 
0.6 

1-7 
1.0 
1.2 
0.6 

1-3 
0.7 
1.6 

0.7 



465 
200 
410 
210 

325 
165 
730 
580 

335 
165 
565 
470 
660 
375 
645 
365 
530 
200 

370 
210 

950 
660 

750 
380 
400 
19s 
405 
230 

445 
230 
885 
460 
700 
325 



* U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 28, p. 47 et seq. 



256 FOOD INSPECTION ^ND /INALYSIS. 

Crustaceans and MoUusks. — These differ from the meats and common 
fish by reason of the presence in considerable proportion of the carbohy- 
drate glycogen, contained in the liver. The lobster and crab arc nearly 
alike in composition, the flesh being made up of coarse, dense, thick-walled 
fibers. 

Payen gives the following composition of the flesh and body of lobster: 

Flesh (contained in Body (consisting 
Claws and Tail). mainly of Liver). 

Water 76.6 84.31 

Protein i9-i7 12.14 

Fat 1. 17 1. 14 

Clams and Oysters are low in solid nutriment, and are more digestible 
vs-hen eaten raw than cooked. Oysters contain 3% or more of glycogen. 
The following analyses are from Atwater and Bryant:* 

COMPOSITION OF SHELL FISH, ETC. 



Refuse. 



Water. 



Pro- 
tein. 
NX 
6.25. 



Fat. 



Car- 
bohy- 
drates. 



Ash. 



Fuel 
Value 

per 
Pound. 

Cals. 



Clams — 
Crabs — 
Lobster- 
Mussels- 
Oysters- 

Scallops- 
Terrapin 

Turtle- 



edible portion, 
as purchased . . 
edible portion, 
as purchased . . 
edible portion, 
as 7)urchased . . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
as purchased. . 
— edible portion . 
as purchased . . 
edible portion, 
as purchased . . 



41.9 
52-4 



61.7 
46.7 
81.4 



75-4 
76.0 



85.8 
49-9 
77-1 
36.7 
79-2 

30-7 
84.2 

44-9 
86.9 
16. 1 
80-3 
74-5 
18.3 
79.8 
19.2 



8.6 

5-0 
16.6 

7-9 
16.4 

5-9 

8-7 

4.6 

6.2 

1.2 

14.8 

21 .2 

5-2 

19.8 

4-7 



0.6 
2.0 
0.9 
1.8 
0.7 
I.I 
0.6 
1.2 
0.2 
0.1 

3-5 
0.9 

0-5 
0.1 



3-7 
0.7 

3-4 



2.6 

1-5 
3-1 
1-5 
2.2 

0.8 

1-9 
i.o 
2.0 
0.4 

1-4 
1 .0 
0.2 
1.2 
0-3 



240 
140 
415 
195 
390 
140 

285 
150 
235 

45 
345 
545 
135 
390 

90 



Characteristics of Fresh Fish. — Fish of all kinds should be eaten when 
perfectly fresh, as it undergoes decomposition much sooner than meat 
when killed. While with meat aging is often beneficial to bring out 
requisite tenderness and flavor, in the case of fish deterioration begins 
almost immediately after death. Even though certain varieties of fish 
may be kept firm and wholesome for some days on ice, the flavor is dis- 
tinctly impaired by long keeping. Fish that is not perfectly firm to the 
touch, or that has abnormally dry scales, or that shows blubber at the 
* U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 28, pp. 52 and 53. 



FLESH FOODS. 



257 



gills, or that possesses the marked odor that accompanies incipient decom- 
position, should not be used as food. 

Methods of Analysis. — These are similar to the methods given for 
meat. 

Preservatives in Fish and Oysters. — Boric acid and borax in mixture 
and sodium benzoate form the most common preservatives of salt dried 
fish and of oysters. In the case of salt codfish, the preservative is sprinkled 
on the surface. Such surface application in some states, as for example 
Massachusetts, is allowed by law. In opened oysters sold in casks and 
kegs, boric mixture has been used commonly in solution in the oyster 
liquor, but is now infrequent. 

The author has found salicylic acid in bottled clam juice and clam 
bouillon. 

CONCENTRATED FOODS. 

Under the name of "condensed" or "concentrated foods" or "emer- 
gency rations" a number of canned preparations arc sold for the use of 
campers, travelers, armies in the field, etc. These consist usually of 
mixtures of dried ground meats and vegetables, pressed together in com- 
pact form, and preserved in tin cans. The claims made for the food value 
of these preparations are, as a rule, extravagant and erroneous, as shown 
by Woods and Merrill,* who give the following analyses of some of these 
foods : 



Net 
Weight 
Con- 
tents. 



Weight of Materials in Package. 



Water. ^ 



Fat. 


Carbo- 
hy- 
drates. 


Grams. 


Grams. 


42.0 


98.0 


9.0 
23.1 
18.5 
23.0 
12.6 


37-9 
46.9 
37-8 
46.6 

76-4 : 


29.6 

32-7 
32.6 


II. 9 • 

68.0 ! 

6.7 


15-3 
90.1 

84.3 
90-5 


94.8 
46.2 

47-9 
160.3 


54-8 


137-0 1 


10.5 

167.3 
48.6 


34-0 

119. 8 

41.9 


"4-5 


52-5 



Ash. 



Total 

Fuel 

Value. 

Cals. 



Ration cartridge, pea, beef, etc 

Blue ration campaigning food, a ... 
" b.. . 

Red ration campaigning food, a 

" b.... 
Ration cartridge, potatoes, beef, etc. 

Emergency ration, a 

•' b 

Emergency ration, a 

b 



Nao meat food 

Army rations 

Standard emergency ration. 



Arctic food 

Tanty emergency ration 

F-A Food Company's stew. 



Grams. 

241 

169 

78 

122 

77 
283 
120 

113 
121 
127 

437 
661 
418 
270 
49 
423 
475 
964 



Grams. 


Grams. 


34-2 


52-9 


76.1 


37-5 


I 


5-6 


33-8 


26.2 


1.2 


5-0 


"7-9 


62.3 


14.2 


56.1 1 


1.9 


8.2 


4-5 


71.8 


5-7 


8-3 


231-3 


56.9 


420.2 


101.2 


23.6 


129.6 


17.0 


50.6 


0-5 


3-2 


30-7 


7S-I 


313-5 


60.2 


638.0 


149-2 



13-9 

8-5 
1-4 
5-7 
1.2 

13-8 
7-8 
2.2 

5-4 
2.9 

12-5 

7-4 

14.0 

10.6 

0.8 

30.1 

10.8 

9.8 



1071 

432 

436 

496 

424 

772 

617 

622 

776 

^88 

1328 

1542 

2198 

1402 

254 

2430 

1482 

2460 



* Maine Exp. Sta., Bui. 75, p. 103. 



258 FOOD INSPECTION AND /IN /I LYSIS. 

REFERENCES ON FLESH FOODS. 

AcKERMAN, D., und KuTsciiicu, F. IU'Ikt Krabljcn I'.xtrakt. Zcits. Untcrs. Nalir. 

(u-iuiss., i,^, 1907, ])|). iHo, (no, and 6ij. 
Andkkws, O. W. l'"k'sli Foods. London, igoo. 
Aknoi.I), ('., iind Mknt/i.i, ('. /ur llnfrrsiuluing von I'li-ischcxtrakt und Ilcfe- 

rxlralvt. I'harin. Zlg., 4g, i(>04, p. 176. 
Association of OlTicial Agricultural Chemists. Mctliods for (lie Analysis of Meat 

and Meal Products. U. S. Dcj)!. oT Agrii ., liur. of Clicni., Hvil. 107 (rev.), p. 

106. 
Baillkt, L. 'I'railr dc rins|)e<tion des viandes. 
Baixani), a. The ("oni|u)sition of Fish, Crustaceans and Molluscs. Conipt. rend., 

126, 1898, ]). 1 721. 
Bausciiaii,, M., und Hauk, Iv Beitriige zur Kcnntnis des I'lcischextraktes. Arl). 

Kai.scrl. Ciesundlu'it.samte, 24, lyoft, p. 552. 
BiGKi.ow, VV. D. Report on Separation of Meat I'roteids. Proceedings of the A. 

O. A. C, igo,^, igo4, 1905. l^. S. l)e])l. of Agric, Bur. of Chem., liul. 81, 

p. 104; Bui. 90, p. 126; Bui. 99, p. 172. 
BiGELOW, W. D., and Cook, V . C. The Se])aration of Proteoses and Peptones from 

the Simpler Amino Hodies. Jour. Am. Cliem. Soc, 28, up6, p. 14S5. 
— Meat I'lxtracls and Similar Preparations. C S. Dejit. of .Agric, Bur. of Chem., 

Bui. 111. 
Cook, F. C Report on the Separation of Meal I'roteids. Proceedings of the A. O. 

A. C, igo6, 1907. U. S. Depl. of .Agric, Hur. of Chem., Hul. 105, ]). gi; Bui. 

116, p. 44. 
Davies, H. E. Searl's Test for Yeast F.xtracl. I'liarm. Jour., 72, 1904, p. 86. 
Douglas's Encyclopiedia for Bacon Curers, Meat lns|H(lors, Local .Authority OlTiccrs, 

etc. Wm. Douglas iS; Sons, London. 
Duff, Jas. C. Manufacture of Sau.sages. New York, i89g. 
FiEHE, J. Ueber den Nachweis von Pferdeilei.sch in I'leisch- und Wunstwaren mittels 

der Pracipitatreaktion. Zeits. Nahr. Unters. Cenuss., 1 ^, 1907, p. 744. 
FiscnoDKR, F. Leitfaden der Praktischen l"'lei.schl)eshau. Berlin, i89g. 
CiAUTiKR, A. Les Toxines. Paris, i8g6. 
CiKiNDi.KV, n. S. Losses in Cooking Meat. V. S. De])t. of .Agric, Ofilcc of Exp. 

Sta., Bui. 102. 
— —The Nitrogenous Con.stituenls of I-lesh. J. Am. Chem. Soc, 26, igo4, p. 1086. 
Grindley, H. S., and Ivmmktt, A. D. 'I'he Chemistry of Flesh. Improved Methods 

for the Analysis of Animal Substances. Jour. Am. Chem. Soc, 27, igDS, 

p. 658. 
The Chemistry of Flesh. A Stuily of the Plu).sphorus Centent of I'ksh. Jour. 

Am. Chem. Soc, 28, 1906, p. 25. 
A Preliminary Study of the Effect of Cold Storage upon Beef and Poultry 

Jour. Ind. and l-'.ng. Chem., i, igog, p. 413. 
CiRiNDi.EY, H. S., and Mojonnier, T. The Artificial Method for Determining the 

Ease and Rapidity of the Digestion of Meats. Studies of the University of 

Illinois, 1, No. 5, 1903, j). 185. 



FLESH FOODS. 259 

Grindlf.y, II. S., and 'rKowiiRinci;, V. I'. Tlu' Chcniislry of Klcsli. A Study of 

the I'rotcids of Hccf I'lcsli. Jour. Am. Chcm. Soc, 2<S, iqoO, pj). 469-505. 
Grinducy, II. S., and Woods, II. S. The Chemistry of Flesh. Methods for the 

Determination of Creatinin and Crcatin in Meats and their Products. J. iJiol. 

Chem., 2, 1907, |). 309. 
GUENTIIKK. The Study of Fishes. 
Klc'KTON, A., unci MURDFIKI.I), R. Ueher den prakli.sc hen Wert der ( dyko^^cnbcstini- 

munj.^ /Aim Narhweis von rferdellcisc h. /cits. Utilcrs. Nahr, Oenu.ss., t^, 

i()07, [). 501. 
KiTA, T. Ueher (he I'Ctlliestimmunj^' im I''leisch und Fiei.sciiwaren mittels dcs Ger- 

benschen A/.id-Hutyrimeters. Arth. f. Ilyg., 51, 1904, p. 165. 
Langworthy, C. F. Fish as Food. U. S. Dept. of Agric., Farmer's lUil. 85, 
i^KiiUKN, S. Preservation and Coloring of Meal Produtc. Merlin, t9or. 
Lkuckakt. Human Parasites. 

McGiLL, A. Commercial Heef Fxtracts. Canada Inland Rev. I.)ept., Ikil. 6^. 
Mallet, J. W. Physiological lOffcct of Creatine and Creatinine, and their Value 

as Nutrients. U. S. Dept. of Agric, Off. of I'Ap. Sta., Hul. 66. 
MiCKO, K. Vergleichende Untensuchung Fleischextrakten und deren Fnsatzmitteln. 

Zeits. Unters. Nahr. Genuss., 5, 1902, p. 193. 
Unlersuchung von I'leisch-, Ilefen- und andercn lOxtrakten auf Xanthinkijrper. 

I. Die Xanthinkorper des Fleischextraktes. Zeits. Unters. Nahr. Genu.ss., 6, 

1903, p. 781. 
Hydroly.sc der Albumosen des I'"lei.sehextraktes. Zeits. Unters. Nahr. Genu.ss., 

14, 1907, p. 253. 
Missouri F^xp. Station, Bui. 25. Com])osition of I'lesh of ('attic. 
MrrciiKLL, C. A. Flesh F'oods. London, /900. 
()STK«rA(;. Ilatidhuch der Fleischhe.shau. 
Pi.NNtNGTON, M. K. Changes Taking Place in ('hickens in Cold Storage. U. S. 

De[)t. of Agric, Yearljook 1907, p. 197. 
Salmon, D. Iv Inspection of Meats for Animal Parasites. U. S. Dept. of Agric, 

liureau of An. Ind., Hul. 19. 
SciLMiDT-MlJLUKiM. Ilandhucli der I'leischkundc Leipsic, 1884. 
Skakl, a. Yea.st F'.xtract and Its Detection. Pliarm. Jour., 71, t903, [)[>. 516 and 

704; 72, 1904, p. 86. 
Stkkkt, J. P. Meat Fxtracts and Meat Prejiarations. Rj)t. Conn. Agi. I'^xp. Sta., 

Rep. 1908, Pt. 9, p. 606. 
'Pkowukidok, p. F. Rejjort on the Separation of Meal Protcids. Proceedings of the 

A. (). A. C. 1908. U. S. Dept. of Agric, Hur. of Chem., Hul. 122, p. 61. 
Vaughan, V. C, and Novy, I-'. G. Cellular Toxines. 
Walley, Thos. a Practical Guide to Meat Inspection. 
Weber, F. C. Rejjort on Meat and Fish. Proceedings of the A. O. A. C. U. S. 

Dept. of Agric, Hur. of Chem., Hul. 122, f). 42. 
Wiley, II. W. Se[)aration of Fle.sh Bases from Proteifis by liromine. U. S. Dept. 

of Agric, Div. of Chem., Hul. 54. 
Chemical Comfxjsition of the Carcasses of Pigs. U. S. \h\>[. of Agric, Hur. of 

Chem., Hul. 53. 



26o FOOD INSPECTION AND ANALYSIS. 

Wiley, H. W., and others. A preliminary Study of the Effects of Cold Storage on 
Eggs, Quail and Chickens. U. S. Dept. of Agric, Bur. of Chem., Bui. 115. 

WiNTGEN, M. Ueber den Nachweis von Hefeextrakt in Fleischextrakt. Arch. 
Pharm., 242, 1904, p. 537. 

Woods, C. D. Meats, Composition and Cooking. U. S. Dept. of Agric, Farmer's 
Bui. 34. 

Zeitschrift fur Fleisch und Milch Hygiene, 1891 et seq. 



CHAPTER IX. 



EGGS. 



Nature and Composition. — Though eggs of various birds are used to 
some extent as food, it is th'e egg of the hen that is in universal use for 
this purpose, and therefore the one which is here for the most part dis- 
cussed, bearing in mind that the structure and composition of all varieties 
of birds' eggs are closely analogous. 

Fig. 60 shows the longitudinal section of a hen's egg. 




(J 

Fig. 60.— Longitudinal Section of a Hen's Egg. a. Shell; b. Double Membrane of Shell; 
c .\ir-chamber; d. Outer, or Fluid Albuminous Layer; e, Thick, Middle Albuminous 
Laver; /, Inner Albuminous Layer; g, Membrane of the Chalaza; hh, the Chalaza; 
i Vitelline Membrane; /, Germ; k, Yolk; /, Latebra. (After Mace.) 

The average weight of a hen's egg is 60 grams, of which the shell 
weighs about 6, the white 36, and the yolk 18. Roughly it contains 70% 
of water, 12% of albumin, and 12% of fat. 

The shell, according to Konig, has the following composition: 

Calcium carbonate 89-97% 

Magnesium carbonate o- 2% 

Calcium and magnesium phosphate 0.5- 5% 

Organic substances 2 .0- 5% 

261 



262 



FOOD INSPECTION AND ANALYSIS. 



The mean percentage composition of the eggs of the hen, duck, and 
plover are, according to Konig, as follows: 



Water, 
Per Cent. 



Proteins. 
Per Cent. 



Fat, 
Per Cent. 



Nitrogen- 
free Sub- 
stance 
Per Cent. 



Salts 
Per Cent. 



In the Dry Sub- 
stance. 



Nitrogen 
Per Cent. 



Fat 
Per Cent. 



Hen's egg 

Duck's egg. . . . . 

Plover's egg 

White of hen's e 
Yolk " " 



73-67 
71.11 

74-43 
85-75 
50.79 



12.55 
12.24 

IO-75 
12.67 
16.24 



15-49 
11.66 

0.25 
31-75 



0-55 
2.18 
0.13 



1. 12 
1. 16 



0.59 
1.09 



7.66 
6.78 

6.75 

14-25 

5-30 



45-99 

53-62 

45-78 

1.78 

64-43 



The Egg-white. — The white of egg has a specific gravity of 1.045, 
and its reaction is always alkahne. It is a transparent, albuminous fluid 
inclosed in a framework of thin membrane. The fibrous portion of 
the membrane is insoluble in water and in dilute acetic acid. 

The composition of the fluid substance of the white of egg, according 
to Lehmann, is as follows: 

Water 82 to 88% 

Solids 13-3% (mean) 

Proteins 12.2% " 

Sugar 0.5% " 

Fats, alkahne soaps, lecithin, cholesterin traces 

Inorganic residue. o . 66% 

The protein substance is for the most part albumin, with a small 
amount of globulin. 

According to Osborne and Campbell * the nitrogen compounds of 
the white of egg are four in number, which they name ovalbumin, ovo- 
mucin, conalbumin, and ovomucoid. No sharp and distinct separation 
of these bodies has yet been made. 

Ovalbumin (albumin) is the chief constituent, and forms by far the 
largest portion of the protein of the egg-white. In 2.5% solution in water, 
ovalbumin starts to coagulate at 60°, and yields a dense coagulum at 64°. 
Stronger solutions require a somewhat higher temperature for coagulation. 

Ovomucin is a globulin-like substance, precipitated from egg-white 
by dilution with water. It is partly soluble in strong sodium chloride 
solution. When dried and washed with alcohol, it is a light white powder. 

Conalbumin bears a close resemblance to ovalbumin, but coagulates 

* Jour. Am. Chem Soc, 22 (1900), p. 422. 



EGGS. 



263 



in dilute salt solution at a lower temperature (below 60°), and the coagu- 
lum is more flocculent than that of ovalbumin. 

Ovomucoid is not coagulable by heat, and may thus be separated 
(imperfectly) by filtering out all the coagulable proteins. 

The last two compounds exist in very small amounts only. 

Preparation of Albumin.* — By beating up the white of egg in water, 
the salts and the albumin are dissolved, while the fibrous portion is insolu' 
ble and is removed by filtration. The filtrate is then treated with a slight 
excess of basic lead acetate, the precipitate decomposed by treatment with 
carbon dioxide, and the lead removed by hydrogen sulphide. The solu- 
tion is warmed cautiously to 60° C, thus beginning to coagulate the 
albumin, a small part of which, coming down in a flaky form, carries 
with it the lead sulphide. On filtering or pouring off the supernatant 
hquid after coohng, one obtains a colorless solution of the albumin, which 
is evaporated to dryness below 40°. The albumin is obtained in the form 
of transparent yellowish, horny scales, which may be pulverized in a 
mortar, if desired. Its specific gravity is 1.262. It is tasteless, odorless, 
and neutral in reaction, and slowly soluble in water. 

The Egg-yolk. — This is much more complex in composition than 
the white. Halhburton thus enumerates the constituents of the yolk: 

(a) Proteins. — Vitellin, the chief one, a globulin resembling myosin. 
Albumin, in small quantities. 

Nuclein, combined chiefly with the iron present. 

(b) Fats. — Olein, palmitin, and stearin. 
A yellow lipochrome or lutein. 

(c) Carbohydrates. — Grape sugar in small quantities. 

(d) Other Organic Constituents. — Lecithin, a phosphorized nitroge- 
nous body alHed both to the fats and to the proteins. 

Cerebrin. 
Cholesterin. 

(e) Inorganic Salts, the most abundant of which is potassium chloride. 
Gobley gives the following composition to the egg- yolk: 



Per Cent. 

Vitellin 15.8 

Nuclein 1.5 

Cerebrin 0.3 

Lecithin 7.2 

Glycerol phosphoric acid 1.2 



Per Cent. 

Cholesterin 0.4 

Fats 20.3 

Coloring matters 0.5 

Salts I . o 

Water 51.8 



* Allen, Com. Org. Anal., Vol. IV, p. 42. 



264 



FOOD INSPECTION y4ND ANALYSIS. 



Osborne and Campbell,* as the result of long and careful experi- 
ments, consider the protein of egg-yolk to be largely if not wholly a lecithin 
compound, having properties of a globuhn, and soluble in sodium chloride 
solution. 

The fat of the egg yolk, which is used in ointments, has the following 
characteristics according to Spaeth rf 

Specific gravity at 100° C 0.881 

Iodine number 68 .48 

Reichert-Meissl value 0.66 

Refractive index at 25° C. (on butyro-refractometer scale) 68.5 

Melting-points of fatty acids 36° C. 

Iodine number of fatty acids 72.6 



The mineral content of the egg is thus shown by Konig: 
COMPOSITION OF THE ASH OF EGGS, 



Ash of 
the Dry 

Sub- 
stance. 



Potash. 



Soda. 



Lime. 



Mag- 



Iron 
Oxide. 



Phos- 
phoric 
Acid. 



Sul- 
phuric 
Acid. 



Silica. 



Chlo. 
fine. 



Hen's egg: entire., 
white. . 
yolk . . . 



3-48 
4.61 
2.91 



17-37 

31-41 

9.29 



22.87 

31-57 

5.87 



10.91 

2.78 

13.04 



1. 14 

2-79 
2.13 



0-39 
0-57 
1. 6s 



37.62 

4.41 

65.46 



0.32 



0.31 
1.06 
0.86 



28.82 
1-95 



The following analyses of eggs were made by Wood and Merrill : % 
AVERAGE WEIGHTS OF EGGS AND PARTS AS PREPARED FOR ANALYSIS. 





Weight 

as 
Received. 


Weight Boiled. 


Shell 
(Refuse). 


White. 






Shell 
(Refuse). 


White. 


Yolk. 


Total. I 


Yolk. 


Turkey 

Goose 

Duck 

Guinea fowl.. . 


Grams. 

105 -5 

190.4 

70 6 

40.2 


Grams. 
II. 7 
24.1 

7-2 

5-6 


Grams. 
60.1 
98-5 
36-5 
20.9 


Grams. 

30-9 
64.8 
24.4 
12.5 


Grams. 

102.7 

187.4 

68.1 

39-0 


Per Cent. Per Cent. 
II. 4 56.5 
12.8 1 52.6 
10.6 I 53.6 
14.4 53-6 


Per Cent. 
30.1 
34.6 
35-8 
32.0 



' Shrinkage due to loss in preparation and cooking. 



* Jour. Am, Chem. Soc, XXII, 1900, p. 413. 
t Abst. Analyst, 1896, p. 233. 
% Maine Exp. Sta., Bui. 75, p. 90. 



EGGS. 

COMPOSITION OF EGGS. 



265 



Protein. 



£■0 
Sin 

2; 



p e 







Trace 


0.8 


32-9 


1.2 


II. 2 


0.9 


9-7 
Trace 


0.8 
0.8 


36.2 


r-3 


14.4 


I.O 


12.3 
Trace 


0.9 
0.8 


36.2 


1 .2 


14-5 


1.0 


12-5 


0.8 


Trace 


0.8 


31.8 


1.2 


12.0 


0.9 


9-9 
0.2 


0.7 
0.6 


33-3 


I.I 


10.5 


1.0 


9-3 


0.9 



^3 
^ o 

03 ft, 
> u 
— a> 

o a. 



Turkey- 



Goose — 



Duck- 



Guinea fowl- 



Hen- 



white 

yolk 

entire edible portion. 

as purchased 

white 

yolk 

entire edible portion. 

as purchased 

white 

yolk 

entire edible portion. 

as purchased 

-white 

yolk 

entire edible portion. 

as purchased 

white 

yolk 

entire edible portion, 
as purchased 



13-8 



14.2 



13-7 



16.9 



i-S 
7-4 
3-4 
1.6 
1.6 
7-3 
3-8 
1-5 
I.I 
6.8 
3-3 
1-5 
1.6 

6-7 

3-5 



7-6 
4.2 
2.2 
2.9 

8.4 
5-1 



6.8 
4.0 
2.1 
2.6 
7-3 
4-3 
1-9 
3-0 
6.1 
4-8 
3-1 



Cal. 

325 

1875 

850 

735 
330 
1975 
985 
860 

315 
1980 

985 

880 

325 
1800 

875 
730 



METHODS OF ANALYSIS. 

Preparation of the Sample.* — The egg is first weighed as a whole and 
afterwards boiled hard, cooled, and again weighed. The shell, white, and 
yolk are then carefully separated and each weighed. After rejecting the 
shell, the yolk and white are separately reduced by a chopping-knife to 
the size of wheat grains. These portions are dried partially at a tem- 
perature not exceeding 45°, weighed, and afterwards ground to a fine 
powder in a mortar. 

Determinations of water, fat, ash, and total nitrogen are made in practi- 
cally the same manner as with flesh foods. 

Little attention has been paid as yet to the complete separation and 
determination of the nitrogen compounds in the white and yolk, and it 
is customary in most cases to express the protein of the whole as NX6.25. 

Determination of Lecithin. — Wiley's Method.'\ — The whole egg, ex- 
cluding the shell, is placed in a flask with a reflux condenser, and boiled for 
six hours with absolute alcohol. The alcohol is then evaporated ofi', and 
the residue treated in like manner for ten hours with ether. After evaporat- 

* Woods and Merrill, Maine Exp Sta., Bui. 75. p. 92. 

t Principles and Practice of Agricultural Analysis, Vol. Ill, p. 431. 



266 FOOD INSPECTION /IND ANALYSIS. 

ing off the ether, the dry residue is rubbed to a fine powder, placed in an 
extractor and treated with pure ether for ten hours. The ether extract 
thus secured is oxidized, after removal of the ether, by fusion with mixed 
sodium and potassium carbonates, and the phosphorus is determined in 
the usual way as magnesium pyrophosphate. The amount of lecithin 
is obtained by multiplying the weight of magnesium pyrophosphate by 
the factor 7.2703, on the basis of Hoppe-Seyler's formula for lecithin: 
C,,H«„NPO«. 

If, for example, an amount of organic phosphorus yielding 0.0848 
gram of magnesium pyrophosphate is found in 54 grams of egg exclusive 
of shell, then 0.0848X7.2703 = 0.61652 and 0.61652X 100-=- 54= 1.14. 
Therefore the percentage of lecithin in the egg is 1.14. 

Preservation of Eggs. — Owing to the porous nature of the shell, the 
moisture of the contents gradually grows less by evaporation, and the egg 
loses in weight. Air also passes in through the shell pores, carrying 
various microbes, which result in ultimate decomposition and spoiling 
of the egg. Nature has provided the shell with a thin surface coating of 
mucilaginous matter, which, however, is easily washed off. This coating 
tends to partially close the pores, and for best results in keeping should 
not be removed by washing. 

Eggs are commonly preserved by protecting them as far as possible 
from the air: This is accompHshed in a variety of ways, the most common 
being to pack the eggs in salt or bran, so that the packing medium fills 
up the interstices between the eggs. Eggs thus packed will keep con- 
siderably longer then when exposed to the air. A solution of salt is some- 
times employed, and also lime water, the eggs being simply packed in 
the solution. The use of lime water is, however, open to the serious objec- 
tion that a disagreeable odor and taste are imparted to the eggs. 

Eggs are sometimes coated with gelatin, vaseline, wax, or gum, so as 
to cover them with an impervious layer, either by dipping them in the coat- 
ing medium, or by varnishing or otherwise applying the substance to the 
egg shell. By far the most efficacious egg coating has been shown by 
experiments in the North Dakota Experiment Station,* and also in Ger- 
many, to be sodium and potassium silicate, or water glass. The fresh 
eggs, preferably unwashed, are packed in a jar, and a 10% solution of 
water glass is poured over them. According to the North Dakota experi- 
ments, at the end of three and a half months, eggs packed in this manner 
the first of August appeared to be perfectly fresh. 

* Farmer's Bui. 103, U. S. Dept. of Agric, p. 18. 



EGGS. 267 

One drawback to this method is that eggs so treated break more easily 
on boiHng, but this may be prevented by carefully piercing the shell with 
a strong needle. 

Cadet de Vanx has proposed immersing the egg in boiling water for 
twenty seconds, the result being that a very thin layer of the egg-white 
next the shell becomes coagulated, thus forming an impervious coating 
inside the shell. 

Cold-storage Eggs. — The preservation of eggs by storage at low 
temperatures has become an enormous industry. The temperature 
employed varies from 24° to 40° C, and the length of storage from one 
to eight months. 

Experiments conducted by Wiley,* under authorization from Con- 
gress, have brought out certain points as to the physical and chemical 
changes that take place during cold storage. After breaking the shell 
and keeping at room temperature one day, the odor of eggs stored for 
3.5 months was different from that of fresh eggs, but was not disagree- 
ble. This odor increased on longer storage, and after 12.6 months 
became very characteristic. After 16.6 months, a musty odor was noticed 
immediately after opening the egg. 

Chemical anaylsis by Cook showed that eggs in storage for one year 
lost 10% of the total weight, due to evaporation of water from the whites. 
Storage also caused a lowering of the amount of coagulable protein and 
of lecithin phosphorus, but an increase in lower nitrogen bodies, pro- 
teoses, and peptones. The acid reaction of yolks diminished during 
storage. 

Microscopical examination by Howard and Read brought out the 
interesting fact that small rosette crystals of an unidentified substance 
appeared in the yolk after storage for 12 months or longer, and this 
observation has since been utilized in the examination of suspected 
samples. 

Physical Examination of Eggs. — Various physical tests have been 
prescribed for ascertaining the approximate age of an egg. Thus, accord- 
ing to Delarne, if the egg, when placed in a 10% salt solution, sinks to the 
bottom, it may be considered perfectly fresh; if it remains immersed in 
the liquid, it is to be considered at least three days old; and if it rises to 
the surface and floats thereon it is more than five days old. This test 

* U. S. Dept. of Agric, Bureau of Chem., Bui. 115. 



268 lOOD INSI'lJ.riON .iN/> /IN/11. YSIS. 

is a very nn\[\\\ one, and is useful only for cf^^s lliat have been kept in the 
;iir. Preserved e^j^s cantiol be j^au^ed by liiis means. 

Tile best iiielliod of examining e^j^s for freshness is "candliii}^," eon- 
sisliii^ ill |)l;i( iu}!; ihe ej^j^ belvvcen a bri}i;hl ii^hl ;uid ihe eye. If the 
i'\<^\i^ is fresh, il will show a uniform rose-colored tint, without dark s|)ots, 
the air eluimber bein^^ small and oe( ■u|)yin^ about one twentieth the 
(■;i|);uil\' of tiic c^}^. If llic v<^y^ is not fresh, it will appear more or less 
cloudy, bcinjj; darker as the v\.{\!^ j^rows older, betomin^ in extreme cases 
()|)a(|ue. At Ihe same time ihe air chamber ^rows larfi;er as the age 
increases. So called " spots " are egj^s which show on candlinfj; black 
|»alciies due lo fimjj;i. 

Opened Ej^ps. In the handling of eggs many become cracked or 
otherwise iniured to an extent which renders them unlit for transporta- 
tion. These are either sold to bakers for immediate use, or else opened 
and kepi from spoiling l)\' freezing, the addition of preser\at ives, or 
drying. The portions of " spot I'ggs" thai do not show evidence of 
damage are also treated by one of these methods. I'^ggs which, 
bi'cause of their oHensi\(' taste, are unlit h)r food, are used in the tanning 
industry. 

Preservatives commonl\- employed in opened eggs are boric acid 
and formaldehyde. The latter is especialb' eUeclixc as an egg |)re- 
servative. If a small (piantil\ be added and stirred into opened eggs 
that have becomi' absolutely putrid, Ihe result is astonishing, 'i'he 
|)roducl is complek-ly deodorized, and exhibits the outward ap])earancc 
at Iras! of fresh eggs. 

{•'ormaldi'liyde, if |)risent, may readily be detected by heating .some 
of the egg directly with the hydrochloric-acid ferric-chloride reagent u.sed 
in testing milk for formaldehyde, carrying out the process exactly as in 
the ca.se of milk. 

Desiccated Egg. Il is ])()ssil)le to e\apoiale to dryness the content*^ 
of the egg to form a powder, the keeping ([ualities of which far exceed 
that of ordinary eggs, while il forms a coiKcnt rated food which lends 
itself much more readily to transportat ion Ihan does the fresh egg in the 
shell. Several brands of desiccated igg aii' on the market, which from 
their analyses are undoubtedly genuine. The following arc analyses 
of two of them, one (A) made by the Hureau of Chemistry, the other (H) 
by the Massaihusetts Stat*' Hoard of Ilc-alth: 



EGGS. 269 

A. li. 

Water 6 . 80 5.95 

Protein ('X/6.25J 45-20 4^-'5 

iVotcin by difference 5 1 • 20 

Fat 38 . 5 40 . 56 

Ash 3.5 5.34 

Egg Substitutes. There have been many prej>arali(>ns in jxiwrlcrcfl 
form sold under this name, nearly all claiming Ifj cr)ntain all the ingredients 
of eggs, but most of them falling far short of these claims. Some of them, 
as for instance those made from rlesiccated skimmed milk, do contain 
nitrogenous matter, but as a rule litllc if any fat. 

Two samj)les of "egg substitute" s(;ld in Massachusetts were analyzed 
with the following results : * 

A. B. 

IVotcin i^>-94 18.72 

tat 3.43 3.40 

Water 6.71 7.01 

Corn-starch, salts, and color- 
ing matter 72.92 70-^7 

A ten-cent package of sample A, weighing about 2 ounces, was alleged 
to be equivalent to 12 eggs. Starch furnished the chief ingrerlif-nt in 
both samples. 

One of the most flagrant examples of fraurj in this connection was a 
product sold under the name "N'egg," advertised to contain the nutritive 
equivalent of the whites and yolks of a dozen eggs, "their composition 
being based on careful scientific analysis of natural eggs." It was fjut 
up in two small boxes, one containing a white anrl the other a yellow 
dry i>owder. Both were entirely devoid of nitrogen, and consisted of 
nearly pure tapioca starch with a little cr>mmon sah, the color of the 
"yolk" being due to Victoria yellow. 

Some egg substitutes are sold under the name of "custard powders," 
and are alleged to take the place of eggs in cooking. These are variously 
made up of mixtures of skim-milk powder, coloring matter, and baking 
y^owder ingredients as shown from the follfjwing analyses: f 



* An. Rep. Mass. State Board of Health, 1895, P* '^TS- 
t V<x)'l and Sanitation, Xov. 25, 1893. 



270 



FOOD INSPECTION y4ND y^N^^ LYSIS. 



CUSTARD POWDERS. 



Starch 

Albuminous compounds 

Soluble roloring matter 

l-Jakiiif^ soda 

Tarlarif acid 

Phosphates 

Carbonates of lime and magnesia 

Chlorides and sulphates 

Water 

Ash 



86.25 

0-59 
0.88 



•83 
■45 



84-45 
0.58 



13. 6() 
0.38 



3 


4 


51-03 

6.01 


26.38 
2.96 


15-33 
13.69 

0.24 

2.70 


50.70 

IO-33 


I I. 00 


9-63 



52.32 

6.00 



22.11 

"•37 



8.20 



53-82 

5.06 

26.71 
6.19 



REFERENCES ON EGGS. 

BORCHMANN, K. Amtliche Kontrollc des Marktvcrkchrs mit Eicrn. Zeits. Fleisch.-u. 

Milchhyg., 17, 1906, pp. 3, 51, 97, 132. 
Langworthy, C. F. Eggs and their Uses as Food. Farmer's Bui. 128. 
Osborne, T. B., and Campbell, G. F. Proteids of the Egg Yolk. Jour. .Am. Chem. 

Soc, 22, 1900, p. 413. 

Protein Constituents of Egg White. Jour. Am. Chem. Soc., 22, 1900, p. 422. 

Prall, F. Ueber Eier-KoiLservierung. Zeits. Unters. Nahr. Genuss., 14, 1907, p. 445. 

Snyder, H. Digestibility of Potatoes and Eggs. Exp. Sta. Bui. 43, p. 20. 

Wiley, H. W. A Preliminary Study of the EfTects of Cold Storage on Eggs, Quail, 

and Chickens. U S. Dept. of Agric, Bur. of Chem., Bui. 115. 



Farmer's Bui. 87. 
" 103. 



Food Value of Eggs, p. 24. 
Preserving Eggs. 



CH.\PTER X. 

CERIL\LS ANT) THEIR PRODUCTS, LEGOfES, \T:GET.\BLES, 

A.VD FRUITS. 

The chief points of difference in composition between the animal 
foods abeady treated of, and those of the vegetable kingdom, are apparent 
in the relative amounts of proteins and carbohydrates. The proteins 
present in the cereals and vegetables differ materially both in character 
and amount from those in the flesh foods, being as a rule present to a 
much greater extent in the meats than in the grains and vegetables. The 
leguminous foods, such as peas, be:ins, and lentils, are, however somewhat 
exceptional in this respect, being comparatively high in nitrogenous 
content. 

The carbohydrates, which in the flesh foods are almost entirely lack- 
ing, and in milk make up about one-third of the solid matter, form 
the most important and abundant class of constituents in the vegetable 
foods. 

The composition of the principal cereal grains is tabulated as follows 
bv ViUier and Collin: 



i I 

Wheat. Barlev. | Rve. 



Mi 



■Kseatt. 



\\ater 

Nitrogenous substances. 

Fat 

Sugar 

Gum and dextrin 

Starch 

Cellulose 

Ash. 



13.6; 


13-77 


15.06 


12.37 


13. II 13.12 


12-35 
1-75 


II. 14 
2-16 


11.52 
1-79 


10.41 
5-32 


7-85 9-85 
0.88 4-62 


1-45 

2-38 

64.08 


1-56 

1.70 

61.67 


0-95 

4.86 

62.00 


I-9I 

1-79 

54-08 


1 2.46 

16-52 3.38 

J ^ i 62.57 


2-53 

1. 81 


5-31 


2.01 

T.Bt 


II. 19 

1-02 


0.63 2.49 



11.66 
9-25 
3-50. 

65.95 

7-29 

2. -2' 



12.93 

10.30 

2.81 

55-81 
J6.43 



The following results of the analyses of ctTtal grains are summarized 
from the work of the Division of Chemistr\', United States Department 

of .\?ricij]Ture : * 



* Bulkrtin 13, pan ^. 



272 



FOOD INSPECT/OM AND ANALYSIS. 
CEREAL GRAINS. 



Barley: 

Mean 

Buckwheat: 
Mean 

Corn, domestic: 

Maximum . 

Minimum 

Mean 

Oats, domestic : 

Maximum . 

Minimum . 

Mean 

Rice: 

Unhuiled 

Unpolished . . . 
Polished 

Rye, domestic: 

Maximum 

Minimum . 

Mean 

Wheat, domestic: 

Maximum 

Minimum. 

Mean 

Wheat, foreign: 

Maximum 

Minimum. 

Mean 



Num- 
ber of 

Analy- 



14 



4 
6 

14 



Weight 

of 100 ., . ^ 
Ker- Moist- 
nels. , """e- 

Grams, i 



4-533 6.47 

3.069, 12.31 

48.312 12.32 

10.608 9.58 

38.979 10.93 



3-«9i; 
2.038J 
2.9181 

i 
2.929 
2.466 
2.132! 



13.02 

7.87 

10.06 

10.28 
11.88 
12.34 



Pro- 
teins. 



4.20I: 11.45 

1.932 9.54 

2.493 10-62 

6.1901 14-53 

2.125I 7.1 

3.866 10.6 

5.723 12.97 

2.250I 8.5 

4.076' 11.47 



11.52 
10.86 

11-55 
8.58 
9.88 

15-05 

9.10 

12.15 

7.95 
8.02 
7.1! 

18.99 

8.40 

12.43 

17-15 

8.58 

12.23 

14-52 

8.58 

12.08 



Ether 
Ex- 
tract. 



Crude 
Fiber. 



Ash. 



2.67 
2.06 

5.06 

2.94 
4.17 

6.14 
0.93 
4.33 

1.65 
1.96 
0.26 



2.30 
1. 16 
1-65 



2.50 
0.28 

1-77 

2.26 

0-73 
1.78 



3. 81 



2.00 
1. 00 
1. 71 

16.65 

8.57 
12.07 

10.42 

0.93 
0.40 

2.50 
1.65 
2.09 

3-72 
1.70 
2.36 



1.87 
2.28 



2.87 



10.57! 1-85 



1-55 
1. 19 
1.36 

4-37 
2.47 

3-46 

4.09 

1-15 
0.46 

2.41 
1. 71 
1.92 

2-35 
1.40 
1.82 

2.04 
1.67 
1-73 



72.66 

63-34 

75-07 
68.97 

71-95 

61.44 
53.70 
58.75 

65.60 
76-05 
79-36 

75.36 
63.61 

71-37 

76.05 
66.67 
71.18 

76.14 
67.01 
70.66 



Wet 
Gluten 



Dry 
Gluten. 



39-05 
12.33 
26.46 

32-57 
18.72 

25-36 



14.65 

4.70 

10.31 

12.33 
7.00 
9.82 



Balland * gives the following percentage composition of beans, lentils, 
and peas: 





Beans. 


Lentils. 


Peas. 




Min. 1 Max. 


Min. 


Max. 


Min. ' Max. 


Water 


10. TO 20.40 

13.81 25.46 

0.98 2.46 

52.91 60.98 

2.46 4.62 

2.38 4.20 


11.70 

20.42 

0.58 

56.07 

2.96 

1-99 


13.50 
24.24 

1-45 

62.45 

3-56 

2.66 


10.60 

18.88 

1.22 

56.21 

2.90 

2.26 


14.20 


Nicrogenous substances 

Fat 


22.48 
1.40 


Suoiars and starches 

Cellulose 


61.10 

5-52 
3-50 


Ash 





* Jour. Pharm. Chem., 1897, pp. 196, 197. 



CERE.-1LS. LEGUMES, yEGET.-IBLES, AND FRUITS. 273 

The composition of potatoes, according to Balland,* is as follows: 



Water. 



Nitroge- 
nous 
Sub- 
stances. 



Fat. 



Sugar 
and 
Starch. 



Cellulose. 



Ash. 



Normal state 
Dried— 



-nunimum . 
maximum, 
minimum . 
maximum. 



66.10 
80.60 



1-43 
2.81 

5 -98 
13-24 



0.04 
0.14 
0.18 

O. ^6 



29-85 
80.28 
89. 78 



0-37 
0.68 
1.40 
3.06 



0.44 
I. 18 

1.66 

4-38 



The composition of the common vegetables, fruits, and berries is thus 
given bv Atwater and Bn-ant.f 



VEGETABLE:^ 



11 






3^ 
_ c • 

^ C.2 



.\sparagu3 — • 
Beans, dried — 
Beans, fresh Lima 

Beets, fresh — 

Cabbage — 

Carrot, fresh — 

Celen.- — 

CauUtlower — 
Cucumber — 

Lettuce — 

Mushrooms — 
Onion, fresh — 

Parsnip — 
Pumpkin — 
Radish- 
Rhubarb — 
Squash — 

Tomato, fresh — 
Turnip — 



as purchased 

as purchased 

-edible portion . . 
as purchased. . . 
edible portion . . 
as purchased. . . 
edible f)ortion . . 

as purchased 

edible portion . . 

as purchased 

edible portion . . 

as purchased 

as purchased 

edible portion . . 

as purchased 

edible portion . . 
as purchased . . . 

as purchased 

edible fxjrtion . . 

as purchased 

edible portion., 
as purchased. . . 
edible portion . . 

as purchased 

edible portion . . 

as purchased 

edible portion . . 

as purchased 

edible portion. . 
as purchased. . . 

as purchased 

edible portion. . 
as purchased 



3 
II 

I 



55-« 



24 



94- 
12. 
68. 

30- 
87. 



1 1-8 

I22.5 

7-1 

I 3-2 

I 1.6 



18 



II 
15 



10 

27 
19 



15-0 



20.0 



20.0 



15-0 



15.0 I 80-5 



ID 



30.0 
40.0 
50.0 



30.0 



..J87. 
.OJ78. 
--83. 

.0 66. 

--193 

.0, 46. 

.-91. 

.0 I 64. 

..94. 
56. 
88. 
44- 
94- 
89. 
62. 



70.0 


1-3 


91.5 \ 1.6 


n-1 


1-4 


88.2 


i-i 


70.6 


-9 


94 -.s 


I.I 


75-6 


-9 


92-3 


1.8 


95-4 


.8 


81. 1 


-7 


94-7 


1.2 



I.O 

Z-S 
1.6 

1-4 
1-6 



1-3 
-9 
.6 

-4 
1-4 

-7 

-9 
1-3 

-9 



2,-3 
59-6 
22.0 

9-9 
9-7 
7-7 
5-6 
4-8 
9-3 
, 7-4 
3-3 
2.6 

4-7 

3-1 

i 2.6 

2.9 

2-5 
I 6.8 

; 9-9 

I 8.9 

13-5 
10.8 

5-2 

: 2.6 

8.3 
5-8 
3-6 

2.2 

9.0 
4-5 
3-9 

8.1 



105 
1605 
570 
255 
215 
170 

145 
125 
210 
leo 

85 

70 

140 

80 



90 

75 
210 

225 
205 
300 
240 
120 

60 
135 

95 
105 

65 
215 
105 
105 
185 

125 



* Jour. Pharm. Cham., 1897, pp. 298-300. 

t Bui. 28, Office of Exp. Station U. S. Dept. of Agriculture. 



274 



FOOD INSPECTION AND ANALYSIS. 



FRUITS. 



n3 






* 3 g 



Apples — 
Apricots- 
Bananas — 

Blackberries — 
Cherries^ 

Cranberries — 
Currants — 
Figs, fresh — 
Grapes — 

Huckleberries- 
Lemons — 

Muskmelons — 

Oranges — 

Pears — 

Pineapple — 
Plums — 

Prunes — 

Raspberries — 
Strawberries — 

Watermelon — 



edible portion 
as purchased . . 
edible portion, 
as purchased. . 
edible portion, 
as purchased . . 
as purchased. . 
edible portion, 
as purchased. . 
as purchased. . 
as purchased., 
as purchased. . 
edible portion, 
as purchased. . 
-edible portion, 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased . . 
edible portion, 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
as purchased. . 
edible portion, 
as purchased., 
edible portion, 
as purchased . . 



29 



28 

5 



25 



23 



24 



59-4 



•4 

•3 

I.I 

i.o 

1-3 
-8 

1.0 
-9 

-4 
1-5 
1-5 
1-3 
1.0 

.6 
1.0 

-7 
.6 

-3 
.8 
.6 
.6 

•5 

.4 

1.0 

-9 
-9 
■7 
1.0 
1.0 
•9 
•4 
.2 



14.2 
10.8 

13-4 
12.6 
22.0 

14-3 
10.9 
16.7 

15-9 

9.9 

12.8 

18.8 

19.2 

14.4 

16.6 

8.5 

5-9 

9-3 

4.6 

II. 6 

8.5 
14. 1 
12.7 

9-7 
20.1 
19. 1 

18.9' 

17-4 
12.6' 

7-4' 
7-0; 
6.7I 

2.71 



1.6 

2-5 



i-S 



4-3 



2-7 



290 
220 

270 

255 

460 

300 

270 

365 

345 
215 
265 
380 
450 
335 
345 
205 

145 
185 
90 
240 
170 

295 
260 
200 
395 
370 
370 
335 
255 
180 

175 

140 

60 



The following analyses of apples made by Browne * are of interest. 
The first four analyses show the changes that occur in the composition 
of a Baldwin apple at different stages of its growth. Below these is 
given the average of the analysis of 160 samples, representing 27 varieties 
of apples. 

COMPOSITION OF A BALDWIN APPLE AT DIFFERENT PERIODS. 



Condition. 


Water. 


Solids. 


Invert 
Sugar. 


Su- 
crose. 


Total 
Sugar. 


Total 
Sugar 
after In- 
version. 


Starch. 


Free 
Malic 
Acid. 


Ash. 


Sugar 
Co- 
efficient. 


Very green.. 

Green 

Ripe 

Over-ripe. .. 


81-53 
79.81 
80.36 
80.30 


18.47 
20.19 
19.64 
19.70 


6.40 
6.46 
7.70 
8.81 


1.63 
4-05 
6.81 
5.26 


8.03 
10.51 

14-51 
14.07 


8. II 
10.72 
14.87 

14-35 


4.14 

3.67 
0.17 


1. 14 

0.65 
0.48 


0.27 

0.27 
0.28 


47.16 
53-10 
75-71 
72.84 



* Penn. Dept. of Agriculture, Bulletin 58. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



275 



AVERAGE COMPOSITION OF 27 VARIETIES OF APPLES. 

Water 83.57 

Solids 16.43 

Invert sugar 7.92 

Sucrose 3-99 

Total sugar 11. 91 

Total sugar after inversion 12.12 

Free malic acid 0.61 

Ash 0-27 

Sugar coefficient 73-76 

The composition of the commoner nuts is shown in the following 
table:* 

NUTS. 



z 



« 



:9 >> 



3 a 
I 0.0 



Almonds — 

Beechnuts — 

Brazil-nuts — 

Butternuts — 

Chestnuts, fresh — 

Cocoanuts — 

Filberts — 

Hickory-nuts — 

Peanuts — 

Pecans — 

Pistachios — 
Walnuts, Calif'nia- 



edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased . . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
-edible portion, 
as purchased . . 



45-0 
40.8 
49.6 
86.4 
16.0 
48.8 

52-1 
62.2 

24-5 
53-2 



73-1 



20.0 

II-5 

21.9 

13.0 

17.0 

8.6 

27.9 

3-8 

6.2 

5-2 

5-7 

2.9 

15.6 

7-S 
15-4 

S-8 
25.8 

19-5 

II. o 

5-2 
22.3 

18.4 

4-9 



54-9 

30 

57 

34 

66 

33 
61 



17-3 

9-5 

13.2 

7-8 
7.0 

3-5 

3 5 

-5 

42.1 

35-4 
27.9 

14-3 

13.0 

6.2 

II. 4 

4-3 
24.4 
18.5 

^3-3 

6.2 

16.3 

13-0 

3-5 



2-5 



1.4 



2.0 
I.I 

3-5 
2.1 

3-9 
2.0 

2-9 

-4 

1-3 

I.I 

1-7 

-9 
2.4 
I.I 
2.1 

.8 
2.0 
1-5 
1-5 

■7 
3-2 
1-7 

-5 



3030 
1660 

3075 
1820 

3265 
1655 
3165 
430 
1125 

945 
2760 

1413 
3290 

1575 
3345 
1265 
2560 
1935 
3455 
1620 

2995 

33°^ 

885 



Vegetables and Fruits furnish a large and most important portion 
of our food supply, but are naturally not included in their fresh state 
among the foods examined by the pubhc analyst for adulteration, hence 

* U. S. Dept. of Agric, Off. of E.xp. Station, Bui. 28. 



276 FOOD INSPECTION AND /IN /I LYSIS. 

but little space need be given them beyond a resume of their composition, 
and an outline of methods of proximate analysis apj)licable to Iheir exam- 
ination for food values. When, however, these products undergo the 
various processes incidental to their treatment for long keeping, such 
as i)reserving, canning, drying, pickling, and mixing with other ingredients, 
il is then that many varieties of fraudulent adulteration are practiced. 
Vegetable foods thus j)rei)arcd form the subject of a separate chapter. 
Besides tlie proximate components that commonly occur in vegetable 
products, there are three other substances worthy of mention found in 
vegetables and fruits, viz., inosite, pcctose, and inulin. 

Inosite, CgHigOg, 2H2O, is not a carbohydrate, but, according to Ham- 
mersten, is an aromatic compound. Besides occurring in unripe fruits, 
it is found in green asparagus and beans. 

Pcctose is a substance the exact nature of which has not been fully 
determined, though it is thought to be a carbohydrate. It gives to unripe 
fruits and vegetables their jjeculiar hardness, and furnishes the basis for 
their gelatinous constituents. When the vegetable or fruit ripens, the 
insoluble pectose is then transformed by the action of acids and possibly 
of ferments into pectin, a vegetable jelly, which gives to fruit juice the 
property of gelatinizing when boiled. 

Inulin, (CgHioOg)^, is a starch-like substance, occurring in the roots 
of chicory and dandelion, and in the tubers of the artichoke. It is a 
white, starch-like powder, slightly soluble in cold, and readily soluble 
in hot water, and converted into levulose by boiling with water, or by 
the action of acids. 

METHODS OF PROXIMATE ANALYSIS. 

Preparation of the Sample. — Cereals and dry leguminous foods are 
prepared for analysis by grinding in a coffee- or spice-mill to such a 
degree of fineness that the powder will pass through a sieve with 60 meshes 
to the inch. Green vegetables, beets, green peas, etc., are best reduced 
to suitable form for analysis by running through a domestic grinding- 
machine of the kind ordinarily employed in the kitchen for grinding 
and shredding meats and vegetables, being by this means reduced to a 
pulp of uniform consistency. 

The following methods are based for the most part on those of the 
Association of Official Agricultural Chemists, employed for the analysis of 
foodstuffs with modifications.* 

* U. S. Dept. of Agric, Div. of Chem., Bui. 46 (rev.), and Bui. 107 (rev.). 



CEREALS, LEGUMES, t^EGETABLES, AND FRUITS. 277 

Moisture. -Two grams of the substance are dried at 100'' C. for 
five hours in a current of dry hydrogen, in a suitable drying oven. 
Results sufificiently accurate for most purposes may be secured by weigh- 
ing the substance into a weighing-bottle or dish, and drying without 
hydrogen in an ordinary water oven. 

Ash. — Two grams of the substance are burned in a platinum dish 
to whiteness at the lowest possible red heat.* If a white ash cannot 
be obtained in this manner, exhaust the charred ma.ss with water, collect 
the insoluble residue on a filter, bum, add this ash to the residue from 
the evaporation of the aqueous extract, and heat the whole to a low 
redness till the ash is white or nearly so. 

Ether Extract (Fat, etc.). — The residue from the determination of 
moisture is extracted for sixteen hours with anhydrous, alcohol-free 
ether in a continuous extractor. The extract is dried to constant weight, 
or the ether extract may be determined indirectly from the difference in 
weight of the dried substance before and after extraction, weighing it for 
convenience in the extraction tube. 

Protein. — The total nitrogen is determined according to the Gunning 
or Kjeldahl method in the absence of nitrates, using i gram of the finely 
divided substance. The protein is calculated by multiplying the total 
nitrogen by the appropriate factor, which varies with the different cereals 
as follows: wheat, 5.70; rye, 5.62; oats, 6.31; corn, 6.39; and barley, 
5.82. Ordinarily the conventional factor 6.25 is employed. 

Crude Fiber (Cellulose, Li^nin, elc.).1[ — The residue, after extraction 
for the determination of the ether extract, is transferred to a 500-cc. flask, 
with a mark showing 200 cc, and boiling 1.2596 sulphuric acid is added 
to the mark. Heat at once to boiling, and boil gently for thirty minutes, 
shaking cautiously from time to time to prevent the material from crawling 
up on the sides of the flask. Filter through paper, and wash once with 
boiling water. Rinse the substance back into the same flask with 200 cc. 
of a boiling 1.2^% solution of sodium hydroxide, free, or nearly so, 
from sodium carbonate, boil at once, and continue the boiling for thirty 
minutes in the same manner as directed above for the treatment with acid. 
Filler on a tared filter-paper, and wash with boiling water till the wash- 
ings are neutral. Dry at iio^ and weigh, after which incinerate com- 
pletely. The loss of weight is crude fiber. A blank experiment should 



* Observe the precautions, indicated on page 134 atx^ut igniting cereals in platinum, 
t Modified from U. S. Dept. of Agric, Div. of Chem., Bui. 46. 



78 



FOOD INSPECTION AND ANALYSIS. 



^ 



be made on a second piece of filter-paper to show the loss occasioned by 
treatment with alkali, and the necessary correction should be made. 

The filter used for the first filtration may be linen, one of the forms of 
glass wool or asbestos filters, or any other form that secures clear and 
reasonably rapid filtration. A gooch was originally prescribed for the 
final filtration, but with many substances is apt to clog. The solutions 
of sulphuric acid and sodium hydroxide are to be made up of the 
specified strength determined accurately by titration, and not merely 
from specific gravity. 

Nitrogen-free Extract {Starch, Sugar, Gums, etc.). — Subtract the sum 
of the moisture, ash, ether extract, protein, and crude fiber, from loo. 

Determination of Moisture in Grain. — Brown and Duvel Method.* 
—This method was devised for purposes of inspection with the view 

of guarding against an excessive amount 
of moisture in corn, which causes de- 
terioration through the growth of bacteria 
and moulds. The determinations are 
made on the whole grain in the apparatus 
shown in Fig. 6i. This consists of a 
condenser-tank {A) and an evaporating- 
chamber {B) with a cover {k), the whole 
supported on a stand (C). Each of the 
flasks {p) rests on a flanged pipe-stem 
triangle, which in turn rests on a wire 
gauze. The apparatus is arranged for 
conducting six distillations at the same 
time. 

Introduce into the distillation-flask (/>) 
ICG cc. of a good grade hydrocarbon oil, 
and ICO grams of the grain (weighed on 
a torsion balance accurate to 0.03 gram), 
and close the neck of the flask with a 
rubber stopper carrying a thermometer 
(g), the bulb of which extends well into 
the mixture of oil and corn. Connect 
the side tube of the flask by means 
of another cork with the condenser-tube (5), and heat with the Bunsen 




Fig. 61. — Brown andDuvel Apparatus 
for Determination of Water in 
Grain. End View. 



* U. S. Degt. of Agric, Bur. of Plant. Ind., Bui. 



99. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 279 

burner until the thermometer registers 190° C, which requires from 
ten to fifteen minutes according to the amount of moisture present and 
the size of the flame. Turn off the flame, and allow to stand eight to ten 
minutes, or until the moisture ceases to drop from the condenser-tube 
into the graduate (/). The number of cc. in the graduate represents 
the percentage of moisture in the grain. 

The results agree closely with those by drying to constant weight in 
a water oven at 100°. 

The hydrocarbon oil should have a flash-point, in an open cup, of 
from 200° to 205° C. It is sold under the name of engine oil. 

CARBOHYDRATES OF CEREALS AND VEGETABLES. 

Classification. — As a n.de the same carbohydrates are found in all 
cereals, being present, however, in var)dng proportions. By far the greater 
part of the carbohydrate content of cereals is starch, the other carbohydrates 
being comparatively small in amount, so that in rough work it is sometimes 
customar}-, though incorrect, to assume the entire amount of so-called 
"nitrogen-free extract" or carbohydrates (as determined by difference) 
to be starch. 

The carbohydrates occurring in cereals may be classified as follows: 

i Starch 
Cellulose 
Pentosans 

r Sucrose 

t=°'-* ssr 

[ Raffinose (traces) 

Starch {C-^^^O^n- — Pure starch is a glistening, white, granular 
powder having a peculiar feeling when rubbed between the thumb and 
finger. It is a very hygroscopic, commercial starch containing about 18% 
of moisture. Starch is ver}^ widely distributed in the vegetable kingdom, 
occurring in almost ever}^ plant at some stage in its growth. 

Starch is insoluble in cold water, alcohol, and ether; it is soluble in 
hot water, though not without change. By boiling with dilute acids, 
starch is first converted by hydrolysis into a mixture of dextrin and 
maltose, and finally by prolonged boiling into dextrose. Malt extract 
also hydrolizes starch in solution. 

Detection. — Starch is best detected, when present to any appreciable 
extent in any mixture, by boiling a portion of the sample in water, cooling, 
and applying a solution of iodine. A characteristic blue color is pro- 
duced if starch is present. Ver}' small amounts of starch are best iden- 



2Ho loon IN'U'ICIION AND ANALYSIS. 



lilicd in powdered rnixlures Wy iipplyiiig a flrop of a solution of iodine 
to the dry jjowdcr on .'i. microscope slide, or, heller, to the powder previously 
rul)l>cd out with w;il(r on ;i '.Jidc iind(-r a, cov(;r-ghiss; the starch granules, 
if |)rc:,cnl, will he colored iiilcnsely hlue hy the iodine, and are at once 
rendered appaicnt when viewed ihrough the mi(:ros(;o])e. 

'I'hoiijdi the cereal and vegeta-hle starches, whatever their origin, are 
identical < liemii ally, the various slanh granules have (crlain ( liaracler- 
Istics, when viewed under the microscope, that render thtir identifi- 
cation easy in most cases. A knowledge of the microscopical aj)[>ear- 
ancc of the <(Mnmon vegelahle starches is of the- uluio,! importance to 
the puhlic analyst, who frec|uently linds them as adulterants of various 
food;., such as coffee, coc oa, spices, etc. I'or microscopical examination, 
))c)wdc-rc-(| sauiplc-s should he: g^round luie cinough io pa:,:, through a 6o or 
80 mesh sieve. 

Classification. The- microscopical ap])caraii( c c)f the- starch granules 
of various j^iains anci vegetahles dilTer in form, :.i/,e, and often in their 
manner oj iMoupiii)';. Thus, at the oiitsc-l, the connrion stare lies may he 
divided as to the microiic c)|)ic al form of thc'ir granules into three classes, 
viz. , circular, irregularly oval, and jtolygonal. To the; first class, in which 
the stare h gr.iiuile- h;is in gc-neral Ihc-c ire ular disk fori.u, helong rye, wheat, 
and harley. I\c-prc' ,ent ing the second (»r irrc-gularly elliptical class are 
the pea, heaii, pol.il", and arrowroot. In the third, or polygonal class, 
should he- included corn, oats, huckwheat , and liic-. In thus character 
i/iiig, the- di;.liiig,uisliiug forms as circular, oval, ;ind polygonal, it should 
he home in mind that vvhili- the tc-ndency of the most lypic:al starch granules 
in each class, when viewc-c| in normal position, is toward the circular, the 
oval, or the polygonal as the c ase may hc', it is not hy any mc;ins true that 
all or even mo:;t of the- gM-anule;, in any one instance perfectly conform 
to one of these shapes throughout. Thus, circular wheat granules, when 
viewed edgewise, will appc-ar elliptical, and are often distorted in shape, 
especially whc-n roasted; and polygonal huckwheat granules may in 
many instances have such ohtuse angles as to ap|)ear circular. It is the 
general trend of all the starchc-s toward one- or another of these shapes 
that suggests the classification. 

'I'he identihcation of the various starches morphologically is indeed 
the most natural and ready method. Not only the c haracter of the starch, 
but also its a])pr()ximate amount, when present in mixtures, can in many 
instances he ascertained hy a careful examination with the microscope. 
'I'he analyst should he providc-d with samples of starches of known 



(J.KI-.AL',.. I.IJ.IJMI:'., l/l:(jl:T/tlil.l:S, /INI J IKIJITS. 2*':i 

purity convenienlly at harul, and in all (\(,\\\)\U\\ cases these shoul'l \)<: 
referred to for comijarisfjn. 

Wheat Starch (Fig, 152, V\. VIII;. — This starch is frequently j^rcsent 
in adulteratcf] [x.-f^f^er, mustard, ginger, cocoa, coffee, and other fofxls. 
Its granules occur for the most j>art in two si/x's, of which the larger 
are circular disks, varying from 0.02/ mm. to 0.041 ^f^^f^-, or rarely 0.0150 
mm., in diameter, while the smaller are rounded or jx^lygonal, averaging 
about 0.005 mm. in diameter. The smaller granules are groufjed irregu- 
larly in and around the larger, there being six to ten of the former to 
one of the latter. The larger granules are, however, the mo.si; distinctly 
characteristic, and are usually rea/lily recogni/x-d in a mixture, not only 
by their shape, but by reason of the concentric rings with which they are 
j>rovided, and which are generally but not always apparent. 

liarley Starch CFig. 124, PI, l;.~This much res<,'mbles wheat, in that 
it has two sizes of granules, but both sizes are re.sfX-'Ctively smaller than 
those of wheat, though present in al)out the .same profK)rtion. The 
larger circular di.sk-like granules vary from 0,013 mm, to 0.035 mm. in 
diameter, while the smaller average 0.003 mm. The concentric rings are 
less apparent in the barley than in the wheat. 

Rye Starch CFig. 148, PI. \i\) has also two sizes of granules, but 
the larger vary from 0.025 mm. to over 0.05 mm. in diameter, and are 
considerably larger than the corresfxjnding wheat granules. The smaller 
granules average alxjut 0.004 mm. in diameter. .As in the case of wheat 
and barley, the larger granules are circular di.sks, while; the .smaller are 
rounded or fxjlygonal. The concentric rings are usually indistinct in the 
large granules, and many of the.sc .show cross-.shafjwl rifts in the center. 

Corn Starch (Fig. 133, PI. IV). — This .starch is a ajmmrjn adulterant 
of spices, cocoa, and other foofls. It is f>lacwl in a .series of four cereal 
starches who.se granules are |x>lygonal, and all of which .show more or 
less tendency to arrange them^selves in clo.se a>ntact side by side in 
masses suggestive of a tesscllaterl or mosaic flof^r. Arranged in order 
of the size of their grains, these .starches are: Com, buckwheat, oats, 
and rice. Com .starch granuk;s tend toward the hexagonal in .shaj>e, 
varying from 0.007 mm. to 0.035 mm, in diameter, and having very 
markerl rifted hila. They are most rearlily recognized in any mixture, 
and from their size are rea/lily distinguishable from the other fx^>Iygonal 
starches, which never reach 0.0/7 "i"i- '" diameter. 

Buckwheat Starch (Fig. 128, J^l. W, and Fig, 129, PI. Ill) .—This is a 
very common ariultcrant of many spices, especially ix;p[>er, which, a,*. 



282 FOOD INSPECTION AND ANALYSIS. 

shown in Fig. 256, PI. XXXIV, it much resembles in the manner in 
which its masses of granules group themselves, conforming to the shape 
of the cells. The individual granules are commonly 0.006 mm. to 0.012 
mm. in diameter. Curious rod-shaped aggregates of two to four indi- 
viduals are of frequent occurrence. 

Oat Starch (Fig. 139, PI. V). — The granules of this starch vary from 
0.002 mm. to 0.012 mm. in diameter, and are polygonal, or less often 
rounded or spindle-shaped in form. They have no rings or hila, and 
arrange themselves in rounded aggregates of from two to many granules 
that at first sight might be mistaken for large grains; careful examina- 
tion, however, shows the dividing lines. 

Rice Starch (Fig. 143, PI. VI).— The granules of rice starch resemble 
closely those of oats both in form and size, but spindle-shaped forms are 
not present. As in the case of oats, the granules are often united to form 
rounded aggregates. 

Starches of the Pea and Bean. — The starches of these legumes much 
resemble each other, and are with diihcultly distinguished one from the 
other (see Fig. 164, PI. XI, and Fig. 154, PI, IX), The granules are 
more nearly oval than most other starches, and have both concentric 
rings and elongated hila. The granules of the pea show a less distinct 
hilum than those of the bean, and some, of them are irregularly swollen. 
Both peas and beans roasted are commonly used as adulterants of 
coffee. 

Arrowroot. — There are many varieties of arrowroot, including Jamaica, 
Bermuda, East Indian, Australian, and others, all having certain varia- 
tions in form and size, but resembling each other in a general way. 
Fig, 167, PI. XII, shows the Bermuda arrowroot, the granules of which 
are somewhat egg-shaped, being usually smaller at one end than the 
other, and having rifted hila near the small end. 

Potato Starch (Fig. 165, PL XII), — This starch has large, irregularly 
oval granules, with very apparent hila situated eccentrically near one 
end, and with rings around the hilum. The granules are about 0.07 mm. 
in large diameter. Fig, 134, PI. IV, and Fig. 166, PI. XII, show corn 
and potato starch when viewed with polarized light with crossed Nicol 
prisms, the specimens being mounted in Canada balsam. 

Tapioca Starch. — The granules of this starch, as shown in Fig. 168, 
PI. XII, are more uniform in size throughout than those already de- 
scribed, averaging about 0.018 mm. in diameter, and being quite smoothly 
circular, without concentric rings, but having a distinctly dotted hilum in 



CEREALS. LEGUMES, l/EGETABLES, AND FRUITS. 2S3 

the center. ^Many of the grains are cup-shaped, as if a segment of the 
circle had been removed. 

Sago Starch (Fig. 172, PI. XIII). — The granules of sago starch vary 
much in size, and might be called irregularly ellipsoidal in shape, being 
provided with numerous protuberances. Some of them have indistinct 
concentric rings, and in some, but not all, a hilum is apparent, usuallv 
near one end of the granule. 

Microscopical Appearances of Starches with Polarized Light. — With 
polarized light starch granules show dark crosses, the point of inter- 
section being at the hilum (Fig. 166, PI. XII). These crosses vary 
in distinctness with the variety. Certain of the starches show a plav 
of colors with polarized light and a selenite plate, especially those whose 
granules have some sort of hilum. This is particularly striking in such 
starches as com, tapioca, potato, and arrowroot. Blyth has made the 
phenomenon a means of classification of the starches, but the writer 
considers their appearance with ordinary light sufficient for identifica- 
tion. Canada balsam is the best mountant for examination in polar- 
ized light. 

Estimation of Starch. — Direct Acid Conversion. — By this method the 
hemiceUulose, if present, or such of the carbohydrates as are capable of 
being converted to sugar, are reckoned in with the starch. \\Tiere httle 
or none of the insoluble carbohydrates other than starch are present, as 
for instance in the case of commercial starches, this method is sufiiciently 
accurate. 

Exhaust 3 grams of the finely di\'ided substance on a fine but rapidly 
acting filter with ether by washing with 5 successive portions of 10 cc. 
each, and wash the residue first with 150 cc. of lo*^ alcohol and then 
with a Httle strong alcohol. Transfer by washing to a flask with 200 cc. 
of water and 20 cc. of hydrochloric acid (specific gravity 1.125), connect 
v\-ith a reflux condenser, and heat the flask in boiling water for 2| hours. 
Cool, and carefully neutrahze with sodium hydroxide, clarifying if neces- 
sar}' \nth alumina cream. Mix well, make up the volume to 500 cc, 
filter, and determine the dextrose in an aliquot part of the filtrate by 
any of the methods for dextrose. Convert dextrose to starch by the 
factor 0.9. 

Diastase Method. — By this method the hemiceUulose is not con- 
verted, only the starch being acted upon. Hence for exact work in the 
presence of other insoluble carbohydrates this method is to be recom- 
mended. Under the action of diastase, starch is first converted into 



284 FOOD INSPECTION AND ANALYSIS. 

maltose and dextrin, and finally into dextrose, in somewhat the following 
manner : 

1 2CeH.„0,+ 4H2O = 4Ci,H3,0,, + 2C,.\i,p,, 

Starch Maltose Dextrin 

C,2H3,0„+ H3O = 2CeH.,Oe Ci,H,„Oio+ 2H,0 = 2C6H,206 

Maltose Dextrose Dextrin Dextrose 

Exhaust 3 grams of the finely divided substance with ether and 
alcohol as in the acid conversion method, wash the residue into a beaker 
with 100 cc. of water and boil directly for 30 minutes, stirring constantly 
and restoring the water lost on evaporation. Cool to 55° C, add 20 cc. 
of malt extract (prepared as below), and maintain at this temperature for 
one hour with occasional stirring. Boil a second time for 15 minutes^ 
cool again to 55° C, and digest once more with 10 cc. of additional malt 
extract. The treatment with malt converts the starch into dextrin and 
maltose. Heat to boiling a third time, cool and make up to 250 cc 
Filter, transfer 200 cc. of the filtrate to a 500 cc. flask, and add 
20 cc. of hydrochloric acid (specific gravity 1.125), connect with a reflux 
condenser and heat in a boiling-water bath for two and one-half hours, 
by which process the dextrin and maltose are converted into dextrose. 
Cool, neutralize carefully with sodium hydroxide (avoiding an excess), 
clarify if necessary with 10 to 20 cc. of alumina cream (p. 587), and 
make up to 500 cc. Mix well, pour through a dry filter, and determine 
the dextrose in an aliquot part of the filtrate, using the factor 0.9 for 
converting dextrose to starch. Correct for the copper reducing power 
of the malt extract, as below. 

Preparation 0} Malt Extract. — Dry malted barley can be readily ob- 
tained from any brewery. Treat 15 to 20 grams of freshly pulverized 
malt for several hours with 100 cc. of water, shaking occasionally. Filter 
the solution, and add two or three drops of chloroform to prevent the 
growth of fungi. Determine the amount of dextrose in a given quantity 
of the malt extract, after boiling with acid, etc., as in the starch determina- 
tion, and make the proper correction. 

Use of " Animal Diastase." — Pancreatin and similar powdered prepa- 
rations, such as " vera diastase " and " panase," obtained from the [ 
pancreas of cattle or hogs, are convenient for use as starch-converting 
reagents instead of malt extract, and are preferable to the latter in that, 
as a rule, they possess no copper-reducing ingredient and hence need 
no correction. 



CEREALS, LEGUMES, l^EGE TABLES, AND FRUITS. 285 

If of the strength of U. S. P. pancreatin, which should convert at least 
twenty-five times its weight of starch, use instead of the malt extract the 
same amount, viz., 20 cc, of a 0.5% aqueous solution of the powdered 
substance in starch determinations as above described. 

Cellulose forms the framework, or skeleton, of all vegetable organisms, 
being, next to water, the most abundant substance in the vegetable 
kingdom. 

Pure cellulose is white, translucent, and of fibrous or silky texture. 
It is insoluble in water, alcohol, and ether, but dissolves readily in an 
ammoniacal solution of cupric hydroxide known as Schweitzer's 
Reagent * or " cuprammonia." 

Cellulose turns violet when treated with chloriodide of zinc, and blue 
when treated with sulphuric acid and iodine in potassium iodide (p. 91). 

The "crude fiber" as determined in foods, being the portion that 
resists the action of hot dilute acid and alkah, is composed largely of 
cellulose. 

The Pentosans are of comparatively small importance, and have been 
little studied. They are amorphous in character, insoluble in water, 
but soluble in dilute alkali, and are capable of conversion by boiling with 
dilute acids into so-called pentose sugars, the best known of which are 
xylose and arabinose, corresponding to the pentosans xylan and araban 
respectively. Strictly speaking the term " hemicellulose " is the more 
appropriate generic term to apply to the insoluble carbohydrate bodies 
which are capable of hydrolysis by acids to sugars, inasmuch as there 
are insoluble bodies besides the pentosans that may thus be converted 
into sugar, such as the hexosans, hydrolyzed by acid to hexose sugars, 
mannose, galactose, etc. The term "wood gum" is also used synony- 
mously with hemicellulose. Since the greater portion of these insoluble 
hydrolizable carbohydrates are pentosans, it is simpler to calculate them 
ail as such. 

Determination of Pentosans. — Pentosans are determined either by 
hydrolyzing to reducing sugar, and estimating the latter as described on 
page 296 (Stone's method) or by calculation from the furfural f yielded 

* Prepared as directed on page 93. 

t Furfural or furfuraldehyde (C5H4O2) is the aldehyde of pyromucic aciji. It is a color- 
less liquid, having an odor suggestive of cassia. Its boiling-point is 162° and its specific 
gravity 1.164. It is sparingly soluble in water and readily soluble in alcohol. Nearly 
half the tissue of ordinary bran, exclusive of proteins and starch, yields furfural on distilla- 
tion with acid. 



286 I'OOD INSri-LTlON AND AN/iLYSlS. 

by Ihcm on distilhilion of the sami^lc with hydrochloric acid, as carried 
out in the provisional method of the A. O. A. C* as follows: 

'iliree grams of the material arc placed in a flask, together with loo cc. 
of 12% hydrochloric acid (specific gravity i.oC) and several j)ieces of 
recently heated ])umice stone. The llask, i)laced upon wire gauze, is 
connecte<l with a condenser, and heat aj^plied, rather gently at first, using 
a gauze lop lo (h'slril)ulc ihc Ilame, and so regulated as to distill over 30 cc. 
in about ten minutes, |)assing the distillate through a small filler. The 
30 cc. driven over are ri|)lac('d by a like (pianlily of the dilute acid, and 
the process continued until the distillate amounts to 360 cc. To the 
comi)leted distillate is gradually added a (|uanlily of phloroglucinol 
(free from diresorcin) dissolved in 12% of hydrochloric acid, and the re- 
sulting mixture is thoroughly stirred. The amount of ])hloroglucinol used 
should be about doiibli' that of the furfural e.xj)ected. Tlie solution 
first turns yellow, then green, and very soon an amorphous greenish 
precipitate api)ears, which grows raj)idly darker, till it finally becomes 
almost black. The solution is made u|) to 400 cc. with 12% hydrochloric 
acid and allowed lo stand over night. 

Till- amorj)h()Us, black i)recij)itate, a condensation jjroduct the exact 
composition of which is unknown, is filtered into a tared gooch through 
an asbestos fell, washed with 1 50 cc. of water in such a way that ihe 
])reci])itale is kejit covered with li(juid until the last portion has passed 
through the filter, dried lo constant weight by heating from three to four 
hours at 100°, cooled in a weighing-bottle, and weighed, the increase 
in weight being reckoned as j)hIoroglucide. To calculate the furfural, 
})entoses, and pentosans from the i)hlorogluci(le, use Krober's formulae 
as follows: 

(a) For weight of |)hloroglucide " a " under 0.03 gram. 

Furfural = (a 4-0.005 2) X 0.5 170. 
Pentoses =(0 + 0.0052) X1.0170. 
Pentosans = (a + 0.0052) X 0.8949. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 54. 



CEREALS, LEGUMES, l^EGETylfiLES, AND FRUITS. 287 

{h) For weight of phloroglucide " a " over 0.300 gram. 

Furfural = ('3 + 0.0052) X0.5180. 
Pentoses = fa + 0.005 2j X 1.0026. 
Pentosans = (a + 0.0052) X 0.8824. 

For weight of phloroglucide "a" from 0.03 to 0.300 gram use Krober's 
table (pp. 288-294) to calculate the weight of fxintoses farabinose, 
xylose), and pentosans faraban, xylan). 

The reactions that take place are thought to be somewhat as follows: 

C,H,0, + H20 = C5H,o05. 

Pentosan Pentose 

C,H,o05 = C.,H/;2 + 3H20. 

Pent/>«/e Furfural 

2C5H402 + CeH603 = C,p,Hi/j6+H;^0. 
Furfural Phloroglucinol Phlorogluckle 

The theoretical yield of phloroglucide .should be 2.22 parts to one of 
furfural, but in practice this is never obtained. The varying factors for 
calculation as above given are based on exfxrriment. 

The phloroglucinol used should be free from diresorcin. To test for 
the latter, di.ssolve the reagent in acetic anhydride, heat nearly to Ixjiling, 
and add a few drops of concentrated .sulphuric acid. If more than a 
faint violet color is procluced, the phloroglucinol should be jjurified as 
follows : 

Heat in a beaker about 300 cc. of hydrochloric acid (sp, gr. i.c6) 
and II grams of commercial phloroglucinol, added in small quantitie.s 
at a time, stirring constantly until it has almost dissolved. .Sf^me im- 
purities may resist .solution, but it is unnece.s.sary to di.s.solve them. 
Pour the hot solution into a sufficient quantity of the same hydrochloric 
acid Ccold) to make the volume 1500 cc. Allow it to stand at least 
overnight — better several days — to allow the dires^'^rcin to crystallize out, 
and filter immediately before using. The s<^)lution may turn yellow, 
but this does not interfere with its usefulness. In using it, arid the 
volume containing the required amount to the distillate. 



288 



HOOD INSI'HCTION /INI) ANALYSIS. 



KRnf'.I.K'S TAULK lOR DiriKKMlNATION OF PENTOSES AND PENTOSANS 
FROM I'ULOROOLUCTI). 



1 


2 


^ 


4 


5 


6 


7 


8 . 


Phloro(<luci'! 


Furfural. 


Aray)inose. 


AraVjan. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


0.030 


O.C182 


. 039 I 


0.0344 


0.0324 


0.0285 


0.0358 


0-0315 


.031 


.0188 


.0402 


-0354 


•0333 


.0293 


.0368 


-0324 


.032 


• ory3 


-04'3 


-03^13 


-0342 


-O301 


■037H 


•03.33 


.033 


.oiy8 


.0424 


-0373 


•0352 


.0309 


.0388 


•0341 


.034 


.0203 


-043.S 


-03«3 


.0361 


•03 '7 


.0398 


-0350 


.035 


.o2oy 


.044''' 


-0393 


.0370 


. 03 26 


.0408 


-0359 


• 03^' 


.0214 


•0457 


.0402 


•0379 


-0334 


.0418 


.0368 


.037 


.0219 


.0468 


.041 2 


.0388 


.0342 


.0428 


-0377 


.038 


.0224 


.0479 


.0422 


.0398 


-0350 


-0439 


-0386 


.030 


.0229 


.0490 


-0431 


.0407 


•035H 


.0449 


-0395 


.040 


•0235 


.050 J 


.0441 


. 04 1 6 


.0366 


-0459 


.0404 


.041 


.0240 


.0512 


-0451 


.0425 


-0374 


.0469 


•0413 


.042 


.0245 


■0523 


. 0460 


-0434 


■ 0382 


■0479 


.0422 


•043 


.0250 


•0534 


.0470 


.0443 


.0390 


.0489 


.0431 


.044 


.0255 


■0545 


.0480 


.0452 


.0398 


.0499 


.0440 


.045 


.0260 


•055^J 


.0490 


.0462 


. 0406 


-0.509 


.0448 


.046 


.0266 


■05^'/ 


.0499 


.0471 


.0414 


-0519 


•0457 


.047 


.0271 


-057« 


.0509 


.0480 


.0422 


-0529 


.0466 


.048 


.0276 


.0589 


•0519 


.0489 


.0430 


-05.19 


-0475 


.o4y 


.0281 


.0600 


.0528 


.0498 


.0438 


-0549 


.0484 


.050 


.0286 


. 06 1 1 


■053« 


.0507 


.0446 


-0559 


.0492 


•051 


.0292 


.0622 


.0548 


.0516 


-0454 


.0569 


.0501 


.052 


.0297 


-0633 


-0557 


■0525 


.0462 


-0579 


.0510 


.053 


.0302 


.0644 


.0567 


-0534 


.0470 


.0589 


-0519 


• 054 


•0307 


•o^'55 


.0576 


-0543 


.0478 


-0599 


.0528 


.055 


.0312 


.0666 


.0586 


■0553 


.0486 


.0610 


•0537 


.056 


.0318 


.or)77 


.0596 


.0562 


.0494 


.0620 


.0546 


.057 


-0323 


.0688 


.0605 


-0571 


.0502 


.0630 


-0555 


.058 


.0328 


. 0699 


.0615 


-0580 


.0510 


.0640 


.0564 


.059 


•0333 


.0710 


.0624 


.0589 


.0518 


.0650 


-0573 


.060 


■OZ?,^ 


.0721 


.0634 


.0598 


.0526 


. 0660 


.0581 


.o6t 


-0344 


.0732 


.0644 


. 0607 


•0534 


.0670 


•0.590 


.062 


■0349 


-0743 


-0653 


.0616 


-0542 


.0680 


•0599 


.063 


-0354 


•0754 


. 0663 


.0626 


-0550 


. 0690 


.0608 


.064 


•0359 


■ 07^^)5 


.0673 


■0635 


•oS.SX 


.0700 


.0617 


.065 


.0364 


.0776 


.0683 


. 0644 


-o5f'7 


.0710 


.0625 


.066 


.0370 


.0787 


.0O92 


■o^\53 


-0575 


.0720 


.0634 


.067 


-037s 


.0798 


.0702 


.0662 


-05«3 


.0730 


.0643 


.068 


.0380 


.0809 


.0712 


.0672 


-0591 


.0741 


.0652 


.069 


•0385 


.0820 


.0721 


.0681 


-0599 


•0751 


.0661 



CEREALS, LEGUMES, l/EGETABLES, AND FRUITS. 



289 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHLOROGLUCID— Co«/?«Merf. 



I 


2 


3 


4 


^ S 


6 


7 


8 


Phlorogluciri 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


0.070 


0.0390 


. 083 1 


0.0731 


0.0690 


0.0607 


0.0761 


0.0670 


.071 


.0396 


.0842 


.0741 


.0699 


.0615 


.0771 


.0679 


.072 


.0401 


.0853 


.0750 


.0708 


.0623 


.0781 


.0688 


.073 


.0406 


.0864 


.0760 


.0717 


.0631 


.0791 


.0697 


.074 


.0411 


.0875 


.0770 


.0726 


.0639 


.0801 


.0706 


.075 


.0416 


.0886 


.0780 


.0736 


.0647 


.0811 


.0714 


.076 


.0422 


.0897 


.0789 


•0745 


.0655 


.0821 


.0722 


.077 


.0427 


.0908 


.0799 


•0754 


.0663 


.0831 


.0731 


.078 


.0432 


.0919 


.0809 


.0763 


.0671 


.0841 


.0740 


.079 


•0437 


.0930 


.0818 


.0772 


.0679 


.0851 


.0749 


.080 


.0442 


.0941 


.0828 


.0781 


.0687 


.0861 


.0758 


.081 


.0448 


.0952 


.0838 


.0790 


.0695 


.0871 


.0767 


.082 


.0453 


.0963 


.0847 


.0799 


.0703 


.0881 


.0776 


.083 


.0458 


.0974 


.0857 


.0808 


.0711 


.0891 


-0785 


.084 


.0463 


.0985 


.0867 


.0817 


.0719 


.0901 


.0794 


.085 


.0468 


.0996 


.0877 


.0827 


.0727 


.0912 


. 0803 


.086 


.0474 


.1007 


.0886 


.0836 


.0735 


.0922 


.0812 


.087 


.0479 


.1018 


.0896 


.0845 


•0743 


.0932 


.0821 


.088 


.0484 


.1029 


.0906 


.0854 


-0751 


.0942 


.0830 


.089 


.0489 


.L040 


.0915 


.0863 


-0759 


.0952 


.0838 


.090 


.0494 


.1051 


.0925 


.0872 


.0767 


.0962 


.0847 


.091 


.0499 


.1062 


.0935 


.0881 


■0775 


.0972 


.0856 


.092 


.0505 


.1073 


.0944 


.0890 


-0783 


.0982 


.0865 


.093 


.0510 


.1084 


.0954 


.0900 


.0791 


.0992 


.0874 


.094 


.0515 


-1095 


.0964 


.0909 


.0800 


.1002 


.0883 


.095 


.0520 


,no6 


.0974 


.0918 


.0808 


.1012 


.0891 


-096 


■0525 


.1117 


.0983 


.0927 


.0816 


.ro22 


.0899 


.097 


.0531 


.1128 


•0993 


.0936 


.0824 


.1032 


.0908 


.098 


■0536 


•"39 


.1003 


.0946 


.0832 


-1043 


.0917 


.099 


.0541 


.1150 


.1012 


-0955 


.0840 


-1053 


.0926 


.100 


.0546 


.ii6i 


.1022 


.0964 


,0848 


.1063 


■0935 


.101 


.0551 


.1171 


.1032 


•0973 


.0856 


-1073 


.0944 


.102 


-0557 


.1182 


.1041 


.0982 


.0864 


.1083 


.0953 


.103 


.0562 


•1193 


.1051 


.0991 


.0872 


■1093 


.0962 


.104 


.0567 


.1204 


.1060 


.1000 


.0880 


.1103 


.0971 


.105 


.0572 


.1215 


.1070 


.1010 


.0888 


.1113 


.0976 


.106 


.0577 


.1226 


.1080 


.1019 


,0896 


.1123 


.0988 


.107 


.0382 


.1237 


.1089 


.1028 


.0904 


'^^?,i 


.0997 


.108 


.0588 


.1248 


.1099 


•1037 


.0912 


."43 


.1006 


.109 


.0593 


.1259 


.1108 


.1046 


.0920 


."53 


.1015 



290 



FOOD INSPECTION AND /IN A LYSIS. 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM Vni.OROG'UJClT)— {Continued). 



I 


2 


3 


4 


5 


6 




8 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


O.IIO 


0.0598 


0.1270 


0.1118 


0-1055 


0.0928 


0.1163 


0.1023 


.III 


.0603 


.1281 


.1128 


.1064 


.0936 


■"73 


.1032 


.112 


.0608 


.1292 


-I137 


■1073 


.0944 


.1183 


. 1041 


.113 


.0614 


•1303 


-I147 


.1082 


.0952 


■1193 


.1050 


.114 


.0619 


-1314 


.1156 


. 1091 


.0960 


.1203 


•1059 


.115 


.0624 


-1325 


.1166 


. IIOI 


.0968 


.1213 


.1067 


.116 


.0629 


-1336 


.1176 


.1110 


.0976 


.1223 


.1076 


.117 


.0634 


■1347 


.1185 


.1119 


.0984 


• 1 233 


.1085 


.118 


.0640 


■1358 


-I195 


.1128 


.0992 


-1243 


.1094 


.119 


.0645 


.1369 


.1204 


-1 137 


.1000 


■1253 


.1103 


.120 


.0650 


.1380 


.1214 


.1146 


.1008 


.1263 


.1111 


.121 


-0655 


-I391 


.1224 


■1155 


. 1016 


•1273 


.1120 


.122 


.0660 


.1402 


-1233 


.1164 


.1024. 


.1283 


.1129 


.123 


.0665 


■1413 


•1243 


■1173 


- 1032 


.1293 


.1138 


.124 


.0671 


.1424 


-1253 


.1182 


. 1040 


-1303 


.1147 


.125 


.0676 


-1435 


.1263 


.1192 


.1049 


-1314 


.1156 


.126 


.0681 


.1446 


.1272 


.1201 


•1057 


-1324 


.1165 


.127 


.0686 


■1457 


.1282 


.1210 


.1065 


-1334 


.1174 


.128 


.0691 


.1468 


.1292 


.1219 


-1073 


.1044 


.1183 


.129 


.0697 


-1479 


.1301 


.1228 


.1081 


■1354 


.1192 


.130 


.0702 


.1490 


.1311 


-1237 


.X089 


-1364 


.1201 


•131 


.0707 


.1501 


.1321 


.1246 


.1097 


-1374 


.1210 


.132 


.0712 


.1512 


•^2,3° 


-1255 


- II05 


.1384 


.1219 


■-^33 


.0717 


■1523 


■ 1340 


.1264 


.1113 


-1394 


.1227 


.134 


.0723 


■1534 


• 1350 


-1273 


.1121 


.1404 


.1236 


-13s 


.0728 


■1545 


.1360 


.1283 


.1129 


.1414 


.1244 


.136 


-0733 


-1556 


.1369 


.1292 


-II37 


.1424 


■1253 


•137 


-0738 


•1567 


■1379 


.1301 


.1145 


-1434 


.1262 


.138 


■0743 


-1578 


.1389 


.1310 


.1153 


.1444 


.1271 


• 139 


.0748 


.1589 


.1398 


•1319 


.1161 


• 1454 


.1280 


.140 


.0754 


.1600 


.1408 


.1328 


.1169 


.1464 


.1288 


.141 


-0759 


.i6ii 


.1418 


-1337 


.1177 


.1474 


.1297 


.142 


.0764 


.1622 


.1427 


.1346 


.1185 


.1484 


.1306 


.143 


.0769 


•1633 


-1437 


-1355 


•I 193 


.1494 


•1315 


.144 


.0774 


.1644 


-1447 


.1364 


.1201 


• 1504 


-1324 


.145 


.0780 


-1655 


•1457 


-1374 


.1209 


•1515 


-1333 


.146 


-0785 


.1666 


.1466 


-1383 


.1217 


•1525 


-1342 


.147 


.0790 


.1677 


.1476 


.1392 


.1225 


•1535 


.1351 


.148 


.0795 


.1688 


.i486 


.1401 


•1233 


.1545 


.1360 


.149 


.0800 


.1699 


•1495 


.1410 


.1241 


.1555 


.1369 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



291 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHLOROGLUCID— (Con/fHMe(f). 



I 


2 


.3 


4 


S 


6 


7 


8 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


0.150 


0.0805 


0. 1710 


0-1505 


0.1419 


0.1249 


0.1565 


01377 


-151 


.0811 


.1721 


-1515 


.1428 


■1257 


-1575 


.1386 


.152 


.0816 


•1732 


•1524 


■1437 


.1265 


•1585 


■1395 


.153 


.0821 


-U43 


•1534 


.1446 


-1273 


■1595 


.1404 


.154 


.0826 


•1754 


.1544 


-1455 


.1281 


.1605 


-I413 


.155 


.0831 


-1765 


-1554 


-1465 


.1289 


.1615 


.1421 


.156 


.0837 


.1776 


-1563 


.1474 


.1297 


.1625 


.1430 


.157 


.0842 


.1787 


-1573 


-1483 


-1305 


-1635 


■1439 


.158 


.0847 


.1798 


•1583 


.1492 


-1313 


.1645 


.1448 


.159 


.0852 


.1809 


•1592 


.1501 


.1321 


■1655 


-1457 


,160 


.0857 


.1820 


.1602 


.1510 


.1329 


.1665 


-1465 


.161 


.0863 


.1831 


.1612 


-1519 


-1337 


-1675 


-1474 


.162 


.0868 


.1842 


.1621 


.1528 


-1345 


.1685 


-1483 


.163 


.0873 


■1853 


.1631 


•1537 


-1353 


.1695 


.1492 


.164 


.0878 


.1864 


. 1640 


-1546 


.1361 


■1705 


.1501 


.165 


.0883 


•1875 


.1650 


•1556 


.1369 


.1716 


.1510 


.166 


.0888 


.1886 


.1660 


•1565 


■1377 


.1726 


-I519 


.167 


.0894 


.1897 


.1669 


.1574 


.1385 


-1736 


.1528 


.168 


.0899 


.1908 


.1679 


-1583 


-1393 


.1746 


■1537 


.169 


.0904 


.1919 


.1688 


-1592 


.1401 


-1756 


-1546 


.170 


.0909 


-1930 


.1698 


.1601 


.1409 


.1766 


-1554 


.171 


.0914 


.1941 


.1708 


.1610 


.1417 


.1776 


-1563 


.172 


.0920 


.1952 


.1717 


.1619 


-1425 


.1786 


■1572 


.173 


■0925 


.1963 


.1727 


.1628 


-1433 


.1796 


.1581 


.174 


.0930 


.1974 


•1736 


-1637 


-1441 


.1806 


•1590 


-175 


•0935 


.1985 


.1746 


.1647 


.1449 


.1816 


.1598 


.176 


.0940 


.1996 


•1756 


.1656 


•1457 


.1826 


.1607 


.177 


.0946 


.2007 


•1765 


.1665 


■ 1465 


.1836 


.1616 


.178 


-0951 


.2018 


-1775 


.1674 


-1473 


.1846 


.1625 


.179 


.0956 


.2029 


.1784 


.1683 


.1481 


.1856 


.1634 


.180 


.0961 


.2039 


-1794 


.1692 


.1489 


.1866 


.1642 


.181 


.0966 


.2050 


.1804 


.1701 


-1497 


.1876 


.1651 


.182 


.0971 


.2061 


.1813 


.1710 


-1505 


.1886 


.1660 


.183 


.0977 


.2072 


.1823 


.1719 


•1513 


.1896 


.1669 


.184 


.0982 


.2082 


.1832 


.1728 


.1521 


.1906 


.1678 


r .185 


.0987 


.2093 


.1842 


-1738 


-1529 


.1916 


.1686 


\ .186 


.0992 


.2104 


.1851 


■1747 


-1537 


. 1926 


.1695 


! .187 


.0997 


.2115 


.1861 


■1756 


■1545 


.1936 


.1704 


=' .188 


.1003 


.2126 


.1870 


.1765 


■1553 


.1946 


.1712 


.189 


.1008 


.2136 


.1880 


•1774 


.1561 


-195s 


.1721 



292 



FOOD INSPECTION /fND ^N^ LYSIS. 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHLOROGLUCID— (CoM/z«Me(f) . 



I 


2 


3 


4 


5 


6 


7 


8 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan, 


0.1 go 


O.1013 


0.2147 


0.1889 


0.1783 


0.1569 


0.1965 


0.1729 


.191 


.1018 


.2158 


.1899 


.1792 


-IS77 


-1975 


■1738 


.192 


.1023 


.2168 


.1908 


.1801 


.1585 


.1985 


•1747 


-193 


.1028 


.2179 


.1918 


.1810 


■1593 


-1995 


-1756 


.194 


-1034 


.2190 


.1927 


.1819 


.1601 


.2005 


.1764 


.195 


.1039 


.2201 


-1937 


.1829 


.1609 


.2015 


-1773 


.196 


.1044 


.2212 


.1946 


.1838 


.1617 


.2025 


.1782 


.197 


.1049 


.2222 


.1956 


.1847 


.1625 


■2035 


.1791 


.198 


.1054 


■2233 


.1965 


.1856 


• ^^33 


.2045 


.1800 


.199 


.1059 


.2244 


.1975 


.1865 


.1641 


-2055 


.1808 


.200 


.1065 


.2255 


.1984 


.1874 


.1649 


.2065 


.1817 


.201 


.1070 


.2266 


.1994 


.1883 


-1657 


.2075 


.1826 


.202 


•1075 


.2276 


.2003 


.1892 


.1665 


.2085 


.1835 


.203 


.1080 


.2287 


.2013 


.1901 


■1673 


-209s 


.1844 


.204 


.1085 


.2298 


.2022 


.1910 


.1681 


-2105 


■1853 


.205 


.1090 


.2309 


.2032 


.1920 


.1689 


-2115 


.1861 


.206 


.1096 


-2320 


.2041 


.1929 


.1697 


.2125 


.1869 


.207 


.1101 


• 2330 


.2051 


.1938 


-1705 


-2134 


.1878 


.208 


.1106 


-2341 


.2060 


-1947 


-1713 


.2144 


.1887 


.209 


.IIII 


-2352 


.2069 


.1956 


. 1721 


.2154 


.1896 


.210 


.1116 


■ 2363 


.2079 


-1965 


.1729 


.2164 


.1904 


.211 


.1121 


■ 2374 


.2089 


-197s 


-1737 


.2174 


■1913 


.212 


.1127 


.2384 


.2098 


.1984 


■ 1745 


.2184 


.1922 


.213 


.1132 


- 2395 


.2108 


-1993 


.1753 


.2194 


-1931 


.214 


■II37 


.2406 


.2117 


.2002 


.1761 


.2204 


.1940 


.215 


.1142 


.2417 


.2127 


.2011 


.1770 


.2214 


.1948 


.216 


.1147 


.2428 


.2136 


.2020 


.1778 


.2224 


•1957 


.217 


.1152 


.2438 


.2146 


.2029 


.1786 


.2234 


.1966 


.218 


.1158 


.2449 


■2155 


.2038 


-1794 


.2244 


-1974 


• 219 


.1163 


.2460 


.2165 


.2047 


.1802 


.2254 


.1983 


.220 


.1168 


.2471 


.2174 


.2057 


.1810 


.2264 


.1992 


.221 


•II73 


.2482 


.2184 


.2066 


.1818 


-2274 


.2001 


.222 


.1178 


.2492 


■2193 


.2075 


.1826 


.2284 


.2010 


.223 


.1183 


-2503 


.2203 


.2084 


.1834 


.2294 


.2019 


.224 


.1189 


-2514 


.2212 


.2093 


.1842 


.2304 


.2028 


.225 


.1194 


• 2525 


.2222 


.2102 


.1850 


•2314 


.2037 


.226 


.1199 


-2536 


.2232 


.2111 


.1858 


-2324 


.2046 


.227 


.1204 


.2546 


.2241 


.2121 


.1866 


-2334 


.2054 


.228 


.1209 


■ 2557 


.2251 


.2130 


.1874 


.2344 


.2063 


.229 


.1214 


.2568 


.2260 


.2139 


.1882 


.2354 


.2072 



CEREALS, LEGUMES, (VEGETABLES, AND FRUITS. 



293 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHLOROGLUCID— (CoK/inuerf). 



I 


2 


3 


4 


S 


6 


7 


8 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


0.230 


0.1220 


0-2579 


0.2270 


0.2148 


0.1890 


0.2364 


0.2081 


.231 


.1225 


.2590 


.2280 


•2157 


.1898 


-2374 


.2089 


.232 


.1230 


.2600 


.2289 


.2166 


.1906 


-2383 


.2097 


•233 


-1235 


.2611 


.2299 


-217s 


.1914 


.2393 


.2106 


.234 


.1240 


.2622 


.2308 


.2184 


.1922 


.2403 


-2115 


.235 


-1245 


-2633 


.2318 


-2193 


.1930 


-2413 


.2124 


.236 


.1251 


.2644 


.2327 


.2202 


.1938 


-2423 


-2132 


.237 


.1256 


.2654 


-2337 


.2211 


.1946 


-2433 


.2141 


.238 


.1261 


.2665 


.2346 


.2220 


•1954 


•2443 


.2150 


•239 


.1266 


.2676 


•2356 


.2229 


.1962 


•2453 


-2159 


.240 


.1271 


' . 2687 


.2365 


.2239 


.1970 


.2463 


.2168 


.241 


.1276 


.2698 


-2375 


.2248 


.1978 


.2473 


.2176 


.242 


.1281 


.2708 


-2384 


•2257 


.1986 


.2483 


.2185 


.243 


.1287 


.2719 


•2394 


.2266 


.1994 


.2493 


.2194 


• 244 


.1292 


.2730 


.2403 


.2275 


.2002 


•2503 


.2203 


.245 


.1297 


.2741 


-2413 


.2284 


.2010 


-2513 


.2212 


.246 


.1302 


-2752 


.2422 


•2293 


.2018 


-2523 


.2220 


.247 


-1307 


.2762 


-2432 


.2302 


.2026 


-2533 


.2229 


.248 


.1312 


-2773 


.2441 


-2311 


.2034 


■2543 


-2238 


.249 


.1318 


.2784 


-2451 


-2320 


.2042 


•2553 


.2247 


.250 


-1323 


.2795 


.2460 


-2330 


.2050 


-2563 


.2256 


.251 


.1328 


.2806 


.2470 


-2339 


.2058 


-2573 


.2264 


.252 


■^333 


.2816 


-2479 


.2348 


.2066 


.2582 


.2272 


.253 


.1338 


.2827 


.2489 


-2357 


.2074 


•2592 


.2281 


.254 


-1343 


.2838 


.2498 


.2366 


.2082 


.2602 


.2290 


.255 


.1349 


.2849 


-2508 


•2375 


.2090 


.2612 


.2299 


.256 


•1354 


.2860 


-2517 


.2384 


.2098 


.2622 


.2307 


•257 


■1359 


.2870 


.2526 


•2393 


.2106 


.2632 


.2316 


.258 


.1364 


.2881 


-2536 


.2402 


.2114 


.2642 


■2325 


.259 


.1369 


.2892 


.2545 


.2411 


.2122 


.2652 


•2334 


.260 


•1374 


.2903 


-2555 


.2420 


.2130 


.2662 


.2343 


.261 


.1380 


-2914 


-2565 


-2429 


.2138 


.2672 


-2351 


.262 


•1385 


-2924 


-2574 


.2438 


.2146 


.2681 


-2359 


.263 


.1390 


.2935 


.2584 


-2447 


-2154 


.2691 


.2368 


.264 


• 1395 


.2946 


-2593 


-2456 


.2162 


.2701 


•2377 


.265 


.1400 


.2957 


.2603 


.2465 


.2170 


.2711 


-2385 


.266 


• 1405 


.2968 


.2612 


-2474 


.2178 


.2721 


-2394 


.267 


.1411 


-2978 


.2622 


.2483 


.2186 


-2731 


-2403 


.268 


.1416 


.2989 


.2631 


.2492 


-2194 


.2741 


.2412 


.269 


.1421 


.3000 


.2641 


.2502 


.2202 


-2751 


.2421 



2 94 



FOOD INSPECTION AND ANALYSIS. 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHLOROGLUCID— (Conc/wrferfj. 



I 


2 


3 


4 


Xyfose. 


6 


"' 7 


8 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylan. 


Pentose. 


Pentosan. 


0.270 


0.1426 


0.3011 


0.2650 


0.2511 


0.2210 


0.2761 


0.2429 


.271 


-1431 


.3022 


. 2660 


.2520 


.2218 


.2771 


.2438 


.272 


-1436 


-3032 


.2669 


.2529 


.2226 


.2781 


-2447 


•27.3 


.1442 


■3043 


. 2679 


.«538 


.2234 


.2791 


.245'' 


.274 


.1447 


•3054 


.2688 


• 2547 


.2242 


.2801 


.2465 


.275 


-1452 


■3065 


.2698 


•2556 


.2250 


.2811 


•2473 


.276 


-1457 


.3076 


.2707 


-2565 


.2258 


.2S21 


.2482 


.277 


.1462 


.3086 


.2717 


•2574 


.2266 


.2830 


.2490 


.278 


.1467 


•3097 


.2726 


■2583 


.2274 


.2840 


.2499 


.279 


■1473 


.3108 


.2736 


-2592 


.2282 


.2850 


.2508 


.280 


.1478 


-3"9 


-2745 


.2602 


.2290 


.2861 


.2517 


.281 


.1483 


■3130 


-2755 


.2611 


.2298 


.2871 


.2526 


.282 


.1488 


.3140 


.2764 


.2620 


-2306 


.2880 


.2534 


.283 


•1493 


.3151 


-2774 


.2629 


• 2314 


.2890 


-2543 


.284 


.1498 


.3162 


-2783 


.2638 


.2322 


.2900 


-2552 


.285 


-1504 


-3173 


-2793 


.2647 


-2330 


.2910 


.2561 


.286 


•1509 


.3184 


.2802 


.2656 


-2338 


.2920 


.2570 


.287 


-1514 


-3194 


.2812 


-2665 


.2346 


■ 2930 


.2578 


.288 


-1519 


-3205 


.2821 


.2674 


•2354 


.2940 


.2587 


.289 


-1524 


.3216 


.2831 


.2683 


.2362 


.2950 


.2596 


.290 


-1529 


•3227 


.2840 


■2693 


.2370 


.2960 


.2605 


.291 


-1535 


-3238 


.2850 


.2702 


-2378 


.2970 


.2614 


.292 


.1540 


.3248 


■2859 


.2711 


• 2386 


.2980 


.2622 


.293 


-1545 


•3259 


.2868 


.2720 


■2394 


.2990 


.2631 


.294 


-1550 


.3270 


.2878 


■2729 


.2402 


.3000 


.2640 


•295 


•1555 


.3281 


.2887 


■2738 


.2410 


.3010 


.2649 


.296 


.1560 


.3292 


.2897 


■2747 


.2418 


.3020 


.2658 


.297 


.1566 


•3302 


.2906 


.2736 


.2426 


.3030 


.2666 


.298 


•1571 


•zzn 


.2916 


• 2765 


• 2434 


.3040 


.2675 


.299 


.1576 


•3324 


.2925 


•2774 


.2442 


•3050 


.2684 


.300 


.1581 


•3335 


.2935 


.2784 


.2450 


.3060 


.2693 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



295 



SEPARATION AND DETERMINATION OF THE VARIOUS CARBOHYDRATES 
OF CEREALS, ETC. STONE'S METHOD. 

Stone has thus tabulated the results of a series of analyses of various 
samples of wheat, flour, com, and bread, in which he has separated the 
principal carbohydrates.* 

PERCENTAGES OF VARIOUS CARBOHYDRATES IN CERTAIN FOODSTUFFS. 



Sucrose. 



Whole wheat, I o. 52 

Whole wheat, II o. 72 

Wheat flour, I o. 18 

Wheat flour, II o. 20 

Com 9.27 

Sugar-beet 8.38 

Bread ("wheat, I) j 0.05 

Bread (wheat, \l) 1 0.06 

Bread (flour, I; o.oi 

Bread (flour, II; 0.15 

Com cake (raaizej 0.16 



Invert 
Sugar. 



Dextrin. I^'^^if 
Starch. 



0.08 

0.00 


0.27 
0.41 


0.00 
0.00 


0.90 

1.06 


0.00 


0.32 


0.07 

0.32 


0-35 
0.68 


0-37 

O.IO 

0.38 

0.19 


0.23 

0.27 
0.91 

0.00 



0.00 
0.00 
0.00 
0.00 
0.00 
0.00 

1-37 
2.36 

1-99 
1-74 

2.8c 



Pento- 
sans. 



4.54 
4.37 
0.00 
0.00 
5-14 



Crude 
Fiber. 



2.68 



1-99 
1. 00 
2.70 
2.02 

0.34 
0.17 
2.22 



Determination of Cane Sugar. — ico grams of the finely ground ma- 
terial are extracted by boiling under a reflux condenser with 500 cc. of 
95';^ alcohol for three hours, the alcoholic extract is filtered, evaporated 
nearly to drjTiess, and then taken up vdih a small amount of water, to 
separate the sugar from the oils and waxes dis.solved by the alcohol. This 
aqueous solution is invariably dextro-rotar}-, and seldom contains any 
reducing sugar. If the latter is present, it is determined in an aliquot 
part of the aqueous solution with Fehling's solution, the result being 
calculated to dextrose. The remainder of the aqueous sugar solution, or 
the whole of it, if, as is almost always the case, dextrose is absent, is 
then inverted by heating with hydrochloric acid in the usual manner 
(page 588) and the sugar is estimated with Fehling's solution, calcu- 
lating the result to sucrose ''page 612). 

Determination of Dextrin. — Digest the residue from the above alco- 
holic extraaion from eighteen to twenty-four hours with 500 cc. of cold 
distilled water, shaking frequently. On filtering, a clear solution is ob- 

* Jour. Am. Chem. Soc., 19, 1897, p. 183, and U. S. Dept. of Agric, Off. of Exp. Sta., 
Bui. 34. The percentages of normal starch found by Stone are obviously erroneous, and 
are for this reason excluded from the table as here given. 



296 FOOD INSPECTION AND ANALYSIS. 

tained, which should be tested with iodine for soluble starch. If the 
latter is not found (which is nearly always the case), the solution is con- 
centrated to a small volume, avoiding a temperature higher than 80'^ to 
90°, and this is boiled under a reflux condenser for two hours with one- 
tenth its volume of hydrochloric acid (specific gravity 1.125). Deter- 
mine the dextrose by Fehhng's solution and calculate to dextrin by the 
factor 0.9. Or, instead of submitting the concentrated aqueous extract to 
hydrolysis as above, the dextrin may be roughly determined gravimetrically 
therein by treating with several volumes of strong alcohol until no further 
precipitation is produced. The flocculent precipitate thus obtained is 
collected, dried, and weighed. 

Determination of Starch. — Dry in an oven the residue from the pre- 
ceding treatment and determine its quantitative relation to the original 
sample ; 2 grams are then accurately weighed and subjected to the dias- 
tase method of starch determination (page 283). 

Determination of Pentosans and Hemicelluloses. — The washed resi- 
due, left after fihering off the starch-containing solution from the process 
of heating with malt extract in the preceding starch determination, is 
boiled for an hour with 100 cc. of 1% hydrochloric acid, which converts 
all the pentosans into sugar. Filter, and wash the residue thoroughly, 
make up the solution to 200 cc, and determine the sugar with Fehhng's 
solution, calculating the results for xylan, assuming that the chief sugar 
formed is xylose. The reducing power of xylose is assumed to be 4.61 
milHgrams for each cubic centimeter of Fehhng's solution. If the volu- 
metric Fehling method is used, 10 cc. of Fehhng's solution are thus 
equivalent to 0.046 gram xylose. Xylose X 0.88 = xylan. 

Crude Fiber {Cellulose, etc.).— The residue from the last dilute acid 
hydrolysis is boiled with 200 cc. of 1.25% solution of sodium hydroxide 
for half an hour, fikered, dried, and weighed. It is then ignited, and 
the weight of the ash deducted from the first weight. 

PROTEINS OF CEREALS AND VEGETABLES. 

Different cereal and vegetable foods present considerable variations 
in the character and extent of their protein constituents, and by no means 
all of the common vegetable foods have been studied in detail. 

Osborne, in connection with Voorhees and Chittenden, has made 
a careful study of the proteins of many of the cereals, of potatoes, and 
of peas. A brief outline only will be given in what follows of methods 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 297 

for separation of the vegetable proteins. For fuller details the reader 
is referred to the work of Osborne et al. in the American Chemical Jourlial, 
Vols. 13, 14, and 15, and to the Journal of the American Chemical Society, 
Vols. 17, 18, 19, and 20. 

Proteins Soluble in Water and Dilute Salt Solution. — By the action 
of various solvents it is possible to separate the different classes of pro- 
teins for examination or analysis. Thus water at first applied extracts 
certain of the soluble proteins, as does a weak salt solution. Osborne 
and \'oorhees recommend the use of a lo^c solution of sodium chloride 
as the first solvent to apply for separating vegetable proteins, shaking 
the finely ground material with twice its weight of the salt solution. The 
salt solution, after filtering, is then subjected to dialysis, the protein matter 
thus separated out being a globulin, while that not precipitated on dialysis 
is assumed as the protein matter of the substance soluble in water. Two 
albumins and a proteose are found in wheat to be thus soluble in water. 

If the proteins soluble in salt solution are to have their total nitrogen 
determined, they are completely precipitated from the solution by satu- 
rating with zinc or ammonium sulphate. 

There are thus two classes of proteins soluble in 10% salt solution: 
(a) globulins, insoluble in water alone, and {h) albumins and proteoses, 
which are soluble in water. 

Separation of Albumins, Proteoses, and Globulins. — Starting with the 
aqueous solution containing the albumins and proteoses, if present, the 
former are best separated according to Osborne and Vorhees by fractional 
coagulation, effected by heating at different temperatures, those that 
precipitate out at a temperature under 65° being first filtered out, and 
the filtrate submitted to a higher temperature not exceeding 85°. The 
two portions thus separated may be collected in filters, and their nitrogen 
separately determined. 

The proteose may be precipitated from the filtrate by saturating with 
ground salt, or by adding, first salt to the extent of 20%, and finally acetic 
acid. 

The globulins, precipitated in the original 10% salt solution by the 
process of dialysis as described, may themselves be separated by employing 
salt solution of var}-ing strength as solvents.* 

Proteins Soluble in Dilute Alcohol, but Insoluble in Water. — The 
residue from the treatment with 10% sodium chloride is digested with 75% 
alcohol at about 46° C. for some time and filtered. The residue is further 

* Am. Chem. Jour., 13, p. 464. 



298 FOOD INSPECTION AND /tN A LYSIS. 

digested at about 60° with 75% alcohol three separate times. The evapo- 
rated filtrates contain the alcohol-soluble proteins. In this class are the 
hordein of barley, the gliadin of wheat and rye, and the zein of corn. 

Proteins Insoluble in Water, Salt Solution, and Dilute Alcohol. — It is 
customary to determine the nitrogen in the final residue without further 
attempt to separate the remaining protein matter. It is, however, possi- 
ble to further extract with alkaline and acid solvents, if desired, which 
process, however, changes the nature of the proteins from that in 
which they originally exist in the substance. 

Character and Amount of Proteins in Wheat.* — The proteins of 
wheat, according to Osborne, are five in number, as follows: 

Amount Present, 
Per Cent. 

Soluble in water: /Albumin (leucosin) 0.3 to 0.4 

I Proteose 0.3 

Soluble in 10 per cent NaCl: Globulin (edestin) 0.6 to 0.7 

Soluble in dilute alcohol: Gliadin 425 

Insoluble in above: Glutenin 4 . 00 to 4 . 5 

The term gluten is applied to the protein content of wheat flour 
insoluble in water, the value of flour for baking bread depending on 
the amount present. Gluten contains the two definite proteins, gliadin 
and glutenin. Crude gluten, as obtained by washing the dough in the 
analytical process (page 319), is a complex mixture of many bodies, 
containing, besides the two proteins above named, small quantities of 
cellulose, mineral matter, lecithin, and starch. 

Separation and Determination of Wheat Proteins. — Teller^ s Method, f — 
Non-gluten Nitrogen. — Two grams of the finely divided sample are mixed 
with about 15 cc. of 1% salt solution in a 250-cc. flask. The flask is shaken 
at intervals of ten minutes during one hour, after which it is filled to the 
mark with the salt solution and allowed to stand two hours. The super- 
natant liquid is then filtered through a dry filter into a dry flask, leaving 
most of the solid material in the flask, passing the first part through twice, 
if necessary, for a clear filtrate. With a pipette, exactly 50 cc. of clear 
filtrate are run into a 500-cc. Kjeldahl digestion-flask, 20 cc. of the usual 
reagent sulphuric acid for the Gunning process (p. 69) are added, and 
the contents of the flask brought to a gentle boil. After the water has 

* Am. Chem. Jour. XV, 392-471; XVI, 524. 
t'Ark. Exp. Sta. Bui. 42, p. 96. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 299 

been driven off and the acid has stopped foaming, the potassium sul- 
phate is added and the digestion completed. From the per cent of 
nitrogen thus obtained 0.27% is deducted, this figure corresponding to 
the amount of gliadin soluble in 1% salt solution under the above con- 
ditions. The remainder is the percentage of non-gluten nitrogen. 

Gluten Nitrogen. — ^This is obtained by difference between the total 
nitrogen and the non-gluten nitrogen as above obtained, or by deducting 
the combined nitrogen of the edestin, leucosin, and the amido-nitrogen 
from the total nitrogen. 

Edestin and Leucojin. — Edestin is a globulin belonging to the vegetable 
vitellins, and is precipitated from salt solutions by dilution, or by satu- 
ration with magnesium or ammonium sulphate, but not by saturating 
with sodium chloride. It is not coagulated below 100° C, but is partly 
precipitated by boiling. Leucosin is an albumin, coagulating at 52°, 
but precipitates from salt solution by saturating with sodium chloride 
or magnesium sulphate. 

To 50 cc. of the clear salt extract, obtained as described under non- 
gluten nitrogen, 250 cc. of pure 94% alcohol are added in a Kjeldahl 500-cc. 
digestion-flask, the contents thoroughly mixed, and allowed to stand 
over night. The precipitate is collected in a lo-cm. filter, which is 
returned to the flask and the nitrogen determined. This represents 
the nitrogen of the combined edestin and leucosin. These proteins 
may, however, be separated by coagulating the leucosin at 60°, and pre- 
cipitating the edestin by adding alcohol to 50 cc. of the clear filtrate, 
determining the nitrogen separately in each precipitate. 

Amido-nitrogen. — Allantoin, asparagin, cholin, and betaine are nitrog- 
enous bases present in wheat. 

Ten cc. of a 10% solution of pure phosphotungstic acid are added 
to 100 cc. of the clear salt extract as above obtained, thus precipitating 
all the proteins, which are allowed to settle preferably over night. Fil- 
ter, and determine the nitrogen in the clear filtrate. The filtrate 
should be tested with a little of the phosphotungstic acid reagent to 
make sure that all the proteins have been separated. In some 
cases, as in bran for instance, more than 10 cc. of the reagent are 
necessary. 

Gliadin is dissolved most readily from flour by hot dilute alcohol, 
but is entirely insoluble in absolute alcohol. One gram of the mate- 
rial is extracted with 100 cc. of hot 75% alcohol, by shaking the mixture 
thoroughly in a flask, and heating for an hour at a temperature just below 



300 FOOD ISSPECTIOS AS'D AS A LYSIS. 

the boiling-point of alcohol, with occasional shaking. After standing 
for an hour, the hot hquid is decanted upon a lo-cm. filter, and 25 cc. 
of the hot alcohol are added to the residue and shaken, after which the 
residue is again allowed to settle, and the hquid decanted. This is 
repeated six times. The remainder of the alcohol is then driven off 
bv evaporation, and the nitrogen determined in the residue. The 
difference between the total nitrogen and the nitrogen thus obtained, 
gives the nitrogen of the alcoholic extract, which includes the amides. 
Subtracting the latter, or amido-nitrogen, the remainder is the gliadin 
nitrogen. 

Glutenin Nitrogen. — This is the difference between the gluten nitro- 
gen and the ghadin nitrogen. 

The factor by which the nitrogen should be multiphed in determin- 
ing the various proteins, according to Osborne and Voorhees, is 5.7 for 
wheat. 

Proteins of the Common Cereals and Vegetables. — Osborne and his 
coworkers have made a detailed study of the protein constituents not 
only of wheat as above outlined, but of other conmion grains and vegeta- 
bles, and the results of these investigations may be thus briefly sum- 
marized : 

Proteins of rve:* 

Per C«at. 

Insoluble in salt solution ;.44 

Soluble in alcohol, gliadin 4..C0 

Soluble in water, leucosin °-43 

Soluble in salt solution: ^ p^^^Qse T ^ • "^ 

S.63 
Proteins of barleyrf Per Cent. 

Soluble in water: -. t>_ - c; 

J Proteose » 

Soluble in salt solution, edestin 1.05 

Soluble in dilute alcohol, hordein 4-~c 

Insoluble in water, salt solution, and alcohol 4-50 

Proteins of com:* 

Soluble in water: Proteose 0.06 

I Very soluble globulin c .04 

Soluble in salt solution: -\ Maj-sin. c.25 

( Edestin. i . ic 

Soluble in dilute alcohol: Zein ^ .co 

Insoluble in above, but soluble in two-tenths per cent potash soludon 3-1; 

Protein of pea:§ 

Soluble id salt solution: Globulins ^ J:f?H°^ '-^ 

> V icilin 3 .CO 

Soluble in water: Albumin, legumelin, proteose 2.CI 



* Jour. -\m. Chem. Soc., 17, page 429. t Ibid., 17, p, 539. 

t Ibid., 19, p. 525. § Ibid., iS, p. 5S3: 2c. pp. 34S and 41c. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 301 

PrcTteins of Potato* — Almost the whole protein content of the potato 
consists of a globulin to which Osborne has applied the name " tuberin." 
Proteose is also present in very small amount. 

MINERAL CONSTITUENTS OF CEREALS AND VEGETABLES. 

The food analyst often finds the determination of one or more of the 
mineral constituents of a food product of value as a means of detecting 
adulteration, since the addition of foreign material may alter materially 
the composition of the ash. 

The tablet on page 302 shows the composition of the pure ash of 
common cereals. 

Scheme for Complete Ash Analysis. — The following scheme in 
essential details was suggested by the late Prof, S. L. Penfield of Yale 
University, and has been in use for over twenty years at the Connecticut 
Agricultural Experiment Station, 

Preparation of Ash. — The amount of material which should be re- 
duced to ash depends on the percentage of total ash present and the 
amount of material available. Usually 100 grams is a suitable amount; 
if, however, the material (e.g., tobacco) is rich in ash, 50 grams is suffi- 
cient, while if it contains but a small amount of ash, 200 grams or even 
more may be required. About 5 gram? of ash is a liberal amount for a 
complete analysis, but in case of necessity i gram will suffice if care is 
taken to so adapt the scheme as to make as many determinations as 
possible on one weighed portion. 

The ashing is carried on in a platinum dish heated below redness 
by a Bunsen burner. In order to distribute the heat and prevent over- 
heating, a piece of asbestos paper is introduced between the dish and the 
flame. The material first chars, then begins to glow just below the 
surface, and the combustion gradually extends downward until it reaches 
the bottom of the dish. Then, and not until then, the unburned carbon 
on the surface should be stirred in with the ash to facilitate burning. 
Care should be taken not to heat higher than dull redness, thus avoiding 
the loss of alkali chlorides and the fusion of alkali phosphates about 
the particles of carbon. A muffle furnace may be used to complete the 
burning. 

Substances rich in starch or sugar are most difficult of combustion, 

* Jour. Am. Chem. Soc, 18, 1896, p. 575. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 13, part 9, p. 1212. 



302 



FOOD INSPECTION AND ANALYSIS. 
COMPOSITION OF ASH OF CEREALS. 



KjO. 



NJaaO. 


CaO. 


9-55 


3-50 


4.64 


5-5O 


6.42 


2.44 


4.3» 


4.09 


7.72 


3.18 


i,Vq8 


4.4« 


2.26 


6.62 



MgO. 



FezOa 



P.O. 



SOa. 


CL 


O.OI 


0.00 


0.52 


0.58 


0.22 


0.56 


0.48 


1.02 


0.44 


0.00 


0.24 


0.80 


3-59 


0.67 



SiOj. 



Wheat (Canada) 

Rye (Minnesota) 

Barley (U. S.) 

Oats (U. S.) 

Corn (U. S.) 

Rice, polished (Guatemala). 
Buckwheat (U. S.) 



24.03 
27.60 
24-15' 
15-91 
33-92 
20.84 

35-15 



13-24 

11-73 

8-23 

7.18J 

17 -99 1 
9.60 

20.55 



0.52 
5-23 
0-33 
0.20 
0.50 
o-8q 



46.87 
41.81 
35-47 
24-34 
35-25 
43.21 
24.09 



2.28 

2.45 
22.30 
42.64 
1 .00 
6.14 
5-54 



Teller * obtained the following results of ash analyses of flour, bran, 
and wheat: 

ASH OF WHEAT PRODUCTS. 



Patent 

Flour. 



Straight 
Flour. 



Low 
Grade. 



Bran. 



Wheat. 



Silica 

Alumina 

Ferric oxide 

Potash 

Soda 

Lime 

Magnesia 

Phosphoric acid. 

Sulphur trioxidc. . .. 

Chlorine 

Zinc oxide 

Sum 

Per cent of total ash 



2-33 
.41 

-47 

38-50 

0.00 

5-59 

4-39 

48.05 

.16 



99.90 



1.28 

•15 
.26 

36-31 
0.00 

5-65 
6.44 

49-32 

-52 

.04 



•50 
.12 

-25 

32.27 

0.00 

4-51 

9-33 

53-10 

.00 



99-97 

.40 



•97 
.07 

-27 

28.19 

0.00 

2.50 

14.76 

18 

10 

01 

27 



52- 



99-95 



1.04 

.11 

.27 

29.70 

0.00 

3.10 

13-23 

52-14 

.22 

.01 

-24 



100.06 
1.62 



Konig gives the following analyses of the ash of various leguminous 
and other vegetables: 





>>?? 




















Ql3 








3< 


.s2 




•0 



i 


'4, 


< 


^ 


^ 





OJ 





0! 




u 


<u 
C 


X 




^-i 




^ 


1^ 


7.08 


o-;7 


38-74 


7.96 


0.86 


36-43 


4.69 


1. 18 


17-33 


4-54 


0.82 


8-45 


4-73 


1.03 


12.46 


3-69 


0.81 


12.71 



Beans . . 

Peas 

Potatoes 
Beets. . . 
Carrots . 
Turnips. 



15 
29 

53 
15 
II 

32 



3-57, 
2-73 
3-77, 
6.44 

5-58, 



42.49 
41.79 

60-371 
54-02 

35-21I 



i-34| 
0.96 
2.62 

15-90 
22.07 



8.011 45.40 9.84 



4-73 
4-99 
2.57 
4.12 
11.42 
10.60 



2-53 


0-73 


3-49 


0.86 


6-49 


2.13 


3-17 


2.38 


6.72 


2.47 


II. 19 


1.87 



1-57 
1-54 
3-11 
8.40 

5-13 
5.01 



* Ark. Exp. Sta. Bui. 42. 



CEREALS, LEGUMES, VEGETABLES, AMD FRUITS. 303 

as the charcoal forms a hard mass, whfle substances rich in fibrous or 
woody matter bum quite readily without losing their powdered con- 
dition. A certain amoimt of unbumed carbon is no disadvantage, as 
it is determined in the course of the analysis. 

Finally cool the ash. grind to a powder, mix without loss, and weigh, 
thus determining the percentage of crude ash. 

Deiermination of Water. — Heat i gram of the ash in a platinum 
crucible well below redness to constant weight. 

Determination of Carbonic Acid. — Determine carbonic acid as 
described on p. 336 using the portion dried for the determination of 
water. 

Determination of Charcoal and Sand. — Weigh i gram of the ash, 
or transfer the solution and residue from the determination of carbonic 
acid, into a beaker, add 25 cc. of water and 25 cc. of 10 p)er cent hydro- 
chloric acid, and boU gently for 10 minutes. Filter on a Gooch crucible, 
and wash thoroughly with hot water. Reserve the filtrate for determina- 
tion of sihca, iron oxide, alumina, lime, and magnesia. ^\'ash the residue 
on the crucible once ^^-ith alcohol and once with ether, and dr\- to 
constant weight at 100^ C. Ignite and weigh again. The loss on 
ignition is the charcoal, the residue is sand. 

Determination of Silica, Iron Oxide, Alumina. Lime and Magnesia. — 
Evaporate to drvTiess in a platinum dish the nitrate from the determina- 
tion of charcoal and sand, heat for some hours on the water bath, and 
dr}- at 130- C. until all hydrochloric acid is removed. Moisten the 
residue thoroughly with concentrated hydrochloric acid, add hot water, 
stir, and decant the solution on an ashless filter. Treat the residue 
again with acid and hot water, and repeat the treatment until nothing 
but silica remains undissolved. Finally collect the silica on the paper, 
wash with hot water, ignite in a platinum crucible, and weigh. 

To the filtrate add ammonia untU a precipitate forms which remains 
on stirring, and then add sufficient hydrochloric acid to just dissolve the 
precipitate. Heat to 50° C. and add an excess of ammonium acetate 
solution and 4 cc. of 80 per cent acetic acid. Digest at 50° C. until 
the mixed phosphates of iron and alimuna have settled, filter, wash with 
hot water, ignite in a platinimi crucible, and weigh. As the precipitate 
is usually slight and consists almost entirely of iron phosphate, the 
iron oxide may be calculated with reasonable acciu^C}' using the 
factor 0.53. If, however, greater accuracy- \s desired fuse the weighed 
precipitate with 10 parts of sodiiun carbonate, dissolve in dilute sul- 



304 FOOD INSPECTION /tND AN /I LYSIS. 

phuric acid, reduce with hydrogen sulphide, determine iron by the 
volumetric permanganate method, and in the same solution determine 
phosphoric acid by the molybdic method. The alumina is obtained by 
difference, subtracting the sum of the weights of the oxide of iron and 
phosphoric acid from the total weight of the precipitate. 

To the filtrate from the mixed phosphates add an excess of ammo- 
nium oxalate, allow to stand in a warm place over night, filter, ignite 
the precipitate in a platinum crucible over a Bunscn burner, and finally 
to constant weight over a blast lamp, thus obtaining the calcium oxide. 

Precipitate the magnesia in the filtrate from the lime by adding 
ammonia to alkaline reaction, then an excess of sodium phosphate solu- 
tion with constant stirring, and finally sufficient concentrated ammonia 
to form one-tenth the final volume. Let stand over night, collect the 
magnesium ammonium phosphate on a Gooch crucible, ignite to mag- 
nesium pyrophosphate, and weigh. 

Determination of Sulphuric Acid, Potash, and Soda. — Boil i gram 
of the ash with dilute hydrochloric acid, and remove charcoal, sand, and 
silica, as described in the preceding section. Evaporate nearly to dryness 
to remove the excess of acid. Dilute to loo cc, heat to boiling, and add 
barium chloride solution drop by drop until the sulphuric acid is pre- 
cipitated. Allow to stand over night, filter, ignite, and weigh as 
BaS04. 

Heat the filtrate to boiling, add enough barium hydroxide to make 
the solution strongly alkaline, filter, and proceed with the determina- 
tion of potash and soda, as described on p. 345. 

Determination of Phosphoric Acid. — Dissolve 0.5 gram of the ash 
in hydrochloric acid, filter, and wash. Neutralize with ammonia, clear 
with nitric acid, and proceed as described on p. 346. 

Determination of Chlorine. — Dissolve i gram of the ash in cold, very 
dilute nitric acid, filter, and wash. To the filtrate add an excess of 
silver nitrate, and heat nearly to boiling with constant stirring. Filter 
on a Gooch crucible, wash with hot water, dry the precipitate at a low 
heat, and heat cautiously at dull redness until the silver chloride has 
partially melted. 

If desired the chlorine may be determined volumetrically by Vol- 
hardt's method, as follows: To the nitric acid solution add a known 
volume of decinormal silver nitrate solution sufficient to precipitate the 
chlorine, and 5 cc. of saturated solution of ferric alum. Titrate with 
decinormal ammonium thiocyanate solution until a permanent brown 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 305 

color is formed. Subtract the volume required from the volume of 
decinormal silver nitrate added, and calculate the chlorine. 

Determination of Sulphur in Vegetable Materials.* — Place from 
1.5 to 2.5 grams of material in a nickel crucible of about 100 cc. capacity, 
and moisten with approximately 2 cc. of water. Mix thoroughly, using 
a nickel or platinum rod. Add 5 grams of pure anhydrous sodium 
carbonate, and mix. Add pure sodium peroxide, small amounts (approx- 
mately 0.50 gram) at a time, thoroughly mixing the charge after each 
addition. Continue adding the peroxide until the mixture becomes 
nearly dry and quite granular, requiring usually about 5 grams of 
peroxide. Place the crucible over a low alcohol flame (or other flame 
free from sulphur), and carefully heat with occasional stirring until 
contents are fused. (Should the material ignite the determination is 
worthless.) After fusion, remove the crucible, allow to cool somewhat, 
and cover the hardened mass with peroxide to a depth of about 0.5 cm. 
Heat gradually, and finally with full flame until complete fusion takes 
place, rotating the crucible from time to time in order to bring any 
particles adhering to the sides into contact with the oxidizing material. 
Allow to remain over the lamp for ten minutes after fusion is complete. 
Cool somewhat. Place warm crucible and contents in a 600 cc. beaker, 
and carefully add about 100 cc. of water. After violent action has ceased, 
wash material out of crucible, make slightly acid with hydrochloric acid 
(adding small portions at a time), transfer to a 500 cc. flask, cool, and 
make to volume. Filter, and take a 200 cc. aliquot for determination 
of sulphates by precipitating with barium chloride in the usual manner. 

Determination of Chlorine in Vegetable Substances.* — Impreg- 
nate 5 grams of substance in a platinum dish with 20 cc. of a 5 per cent 
solution of sodium carbonate, evaporate to dryness, and ignite as 
thoroughly as possible. Extract the residue with hot water, filter, and 
wash. Return to the platinum dish, ignite to an ash, dissolve in nitric 
acid, and determine chlorine by the Volhard method (p. 304). 

MICROSCOPY OF CEREAL PRODUCTS. 

A study of the histology of the various cereal grains is beyond the 
scope of the present work, and the reader who wishes to pursue this 
branch of the subject is referred to the special treatises on this subject. 

* A. O. A. C. Method, U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), pp. 23, 24. 
t Ibid, p. 24. 



3o6 FOOD INSPECTION AND ANALYSIS. 

The characteristics of the tissues of the various ground cereal grains are 
quite distinctive, when carefully studied, sufficiently so, at least, to serve 
to identify the particular grain from which a given product is made. In 
the case of flour and some other products, however, the tissues are 
largely removed in the process of milling, and such fragments as remain 
are so small as to render identification difficult. Products of this nature 
are identified either by the character of the starch grains— as for 
example, in the detection of wheat or corn flour in buckwheat flour — 
or else, if the starch is not sufficiently characteristic — as in the detection 
of wheat flour in rye flour — by examining the tissues accumulated from 
a considerable amount of the material after removal of the starch. 

We have already seen, that the various cereal starches differ con- 
siderably in morphology and mode of grouping from each other, and 
this is true to such an extent that the expert can readily identify them. 
Since starch furnishes much more than half the content of ah ground 
cereals, any considerable admixture of one flour with another is nearly 
always rendered apparent by a careful study of the magnified starch 
grains, which form a large part of the field when viewed under the micro- 
scope. 

The most convenient method of accumulating the tissues from flour 
is to mix thoroughly 2 grams of the material with 200 cc. of water and 
2.5 cc. of sulphuric acid, bring to a boil, allow to settle, and carefully 
decant off the liquid. After transferring to a capsule by means of a 
little water, and removal of the latter by decantation, the tissues are 
mounted for examination in very dilute potassium hydroxide solution. 

Wheat Products. — ^Fig. 62 and PL VIII show the principal elements 
of the wheat kernel. 

The outer layer or epicarp (Fig. 62, epi^ and epi-) consists of beaded 
cells, which on the body of the kernel are elongated, but at the end are 
polygonal. From this layer at the end of the kernel arise the hairs (Fig. 
62, /, PL VIII, Fig. 151) which form a beard clearly visible under a 
lens. Some of these hairs become detached in milling, and pass endwise 
through the bolts, hence their presence in even the highest grade of 
flour. The second layer or hypoderm (hy) resembles the first, while the 
third, although likewise made up of beaded cells, is strikingly different and 
forms the most characteristic tissue of the grain. These cells (Fig. 62, 
tr, PL VIII, Fig. 150) being transversely extended are known as " cross 
cells,'' and are further distinguished from the outer layers by their 
arrangement side by side in rows. The cells of the intermediate layer 



CEREALS, LEGUMES. VEGETABLES, AND FRUITS. 



307 



(Fig. 62, in) and the tube cells [tu^ and /«-), although of striking appear- 
ance, are not of as frequent occurrence as the other layers. The crossing 
layers of the seed coat or spermoderm ()" and 0), are often met with, and 
are characterized by the thin walls of the cells and their brownish color. 
The peris perm (P), consisting of colorless cells, is seldom seen, except 
after special preparation, while the next layer, made up of aleurone cells 




Fig. 62. — Wheat. Elements in Surface View. X160. (WlXTOX.) 
epi^ epicarp at end of grain, with t hairs; epU epicarp on body of grain; hy hj'poderm 
first layer of mesocarp); in intermediate cells; tr cross cells; tu^ typical tube cells; /m2 tube 
cells passing into spongy parenchyma; outer layer of spermoderm; i inner layer of sperm- 
oderm; P perisperm; al aleurone cells; am starch grains. 



(Fig. 62, al\ PI. Vm, Fig. 150), is the most conspicuous of the kernel. 
This layer is not, however, characteristic of wheat, as it is found in aU 
cereal grains and in buckwheat. The aleurone cells do not contain, as 
was formerly supposed, the gluten of the grain; this occurs with the 
starch in the thin-walled cells within tlic aleurone layer. 

The starch granules (Fig. 62, am; PI. VIII, Fig. 152) are described 



3o8 



FOOD INSPECTION AND ANALYSIS. 



on page 281. The starch cells and the aleurone cells together form the 
endosperm. 

The germ, situated at one side of the lower end of the kernel, is made 
up of very small cells containing fat and protein, but no starch. 

Rye Products. — The structure of rye (Fig. 63; PI. VII) resembles 
closely that of wheat. The number and general characters of the cell 
layers are the same in both, and the starch granules are very much alike. 
There are, however, certain points of difference which serve to dis- 




FlG. 63. — Rye, Outer Bran Layers in Surface View. Epicarp consists of porous cells with / 
hairs, and r hair scars; qu cross cells. X i6o. (Moeller.) 



tinguish the products of the two cereals, and even to detect the presence 
of a wheat product in a rye product, and vice versa: 

First. The breadth of the cavities of wheat hairs is usually less than 
the thickness of the walls, whereas in rye hairs the reverse is often true 
(Figs. 62 and 63, /). 

Second. The cross cells of wheat have rather thick, distinctly beaded 
side walls, and thin, pointed end walls; the cross cells of rye have rather 
thin, indistinctly beaded side walls, and usually swollen, rounded end 
walls (Figs. 62 and 63, tr\ Figs. 150 and 146). 

Third. The large starch granules of wheat seldom reach 0.050 mm. 
in diameter, while those of rye frequently exceed that limit. Radiating 
clefts often occur in the starch granules of rye (PI. VII, Fig. 148). 

Fourth. Wheat flour yields a considerable amount of gluten when 



CEREALS, L^'GUMES, VEGETABLES, AND FRUITS, 



309 



treated according to Bamihl's test (page 322); rye flour yields none or 
only a trace. 

Barley Products. — The common varieties of barley are " chaffy," 
that is, the grain after threshing is still closely invested by the chaff 
(PI. I, Fig. 123). The grain within the chaff is analogous in structure 
to wheat and rye, but differs from these in that the cross cells are not 
beaded and form a double layer (Fig. 64, (r), and the starch granules 




Fig. 64. — Barley. Surface view of tr double layer of cross-cell; lu tube cells; ie seed coat. 

X 3CO. (MOELLER.) 



seldom exceed 0.035 ^^- ^^ diameter (PL -I, Fig. 124). The starch is 
more fully described on page 281. 

Corn Products. — The most characteristic element of corn is the 
starch (page 281; PI. IV). Polygonal starch granules 0.017 to 0.030 
mm. in diameter occur in no other vegetable product of economic im- 
portance, excepting the seeds of Kaffir corn and other grains belonging 
to the genus Sorghum, which are used chiefly for cattle or poultry foods. 

Oat Products. — The oat kernel resembles barley in appearance, 
but is not ribbed. In the preparation of oat meal and other breakfast 
foods, the chaff (PL IV, Fig. 135; PL V, Fig. 137) is removed and 
utilized as a cattle food. The elements of the grain of chief value in 
identification are the hairs and the starch granules. The hairs (PL V, 
Fig. 138) are much longer than those of wheat, rye, and barley, often 
reaching i mm. They taper toward both ends, so that when detached 
they often appear to be pointed at the base as well as at the apex. The 



3io 



FOOD INSPECTION /IND ANALYSIS. 



Starch granules are small, of the polygonal type, and often occur in egg- 
shaped aggregates (page 282; PI. V, Fig. 139). 

Rice Products. — The chaff which envelopes this grain is rough and 
silicious, and after removal from the inner kernel is not suited even for 




Fig. 65. — Rice. Bran coats in surface view. epi epicarp; mes mesocarp; tr cross cells; 
/M tube cells; 5 seed coat; TV peri sperm. X300. (Winton.) 

cattle food. Its appearance under the microscope is shown in Plate VI, 
Fig. 142. The thin skin of the kernel proper is largely but not entirely 



^ in/ 




r al 



Fig. 66. — Buckwheat. Bran coats in surface view. Seed coat consists of outer epidermis, 
w spongy parenchyma, and ep inner epidermis; al aieurone cell. X300. (Moeller.) 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



3" 



removed in the preparation of rice for the market. The elements of this 
skin are shown in Fig, 65, the outer layer (epi) being the most char- 
acteristic. Unlike wheat, rye, and barley, it has no beard. Rice starch 
(PI. \T, Fig. 143^ is hardly distinguishable from oat starch. It is 
described on page 282. 

Buckwheat Products. — In the preparation of buckwheat flour the 
black outer hulls and the inner skin or bran are largely, but not com- 
pletely, removed. The bran elements are characteristic constituents of 
the flour, and are rendered especially distinct by adding a drop of dilute 
potassium hydroxide solution to a water mount (Fig. 66). The cells 
with wavy walls {0) and the spongy parenchyma (m) are especially 
noticeable. The starch of buckwheat resembles that of oats, but the 
individual granules are som.ewhat larger and occur in rod-shaped, not 
egg-shaped, aggregates (page 281; PI. II, Fig. 128). Masses of starch 
granules (PI. Ill, Fig. 129) conforming to the shape of the cells, occur 
in abundance in the flour. 

FLOUR. 

Flour is the term applied to the finely ground and bolted substance 
of wheat and other grains, though, unless otherwise qualified, by the 
term "flour" is generally understood that of wheat. In the process 
of manufacture, the dried wheat or grain is first crushed between mill- 
stones, forming the comparatively coarse product knowTi as whole meal. 
This, by bolting, may be separated simply into flour and bran, but in the 
crude milling of years ago at least three products were usually obtained 
from wheat, viz., fine flour, coarser shorts, or middlings, and bran. 

In the improved modem processes of milling, which meet the de- 
mands for the xery finest flour, as well as other grades, the material is 
subjected to repeated sifting and grinding between grooved rollers, with 
ihe result that it is possible to turn out as many as ten separate grades 
of flour, as is shown bv the following record of a mill near Trieste: 



Groats,* A and B 



Bran 
Loss 



r, No. 







I 


(( 


2 . 


« 


7 


« 


A 


<c 




« 


6 


<c 


7 


« 


8 


« 












2 per cent 



14 
9 



18 

3 



• 41 per cent extra flour 



38 per cent medium and common 



21 per cent waste 



100 percent 
* Masses of the interior of the berrv. 



3T2 



FOOD INSPECTION AND ANALYSIS. 



Analyses of these separated products made by C. A. Pillsbuiy' are 
as follows: 



Groats 

No. o 

" I 

" 2 

" 3 

" 4 

" 5 

" 6 

" 7 

" 8 

" 9, coarse bran 

" 10, fine bran. . , 



Water. 



IO-57 
IO-37 
JO. 23 
10.47 
10.07 
'J. 24 
9.66 
II. 12 
10.99 
9.86 
9.71 



Ash. 



0.42 

0-43 
0.41 
1.03 
1.02 
1. 19 
0.69 
1.04 
0.81 
I. or 

7-32 
4.21 



Phosphoric 
Acid. 



0.20 
0.14 
0.21 
0.22 
0.17 
0.25 

0-35 
0.24 
0.21 
0.36 
2.14 
0.70 



Nitrogen. 



24 



Proteins 
Calculated. 



14.65 
10.76 
10.76 
II .02 
11.02 
II. 15 

11-54 
11.79 

"-54 
12.18 
12.69 
14.16 



In this country the common practice of most mills is to produce about 
three grades of flour, somewhat as follows: 



ICO lbs. wheat. 



Patent or middlings flour, 
Bakers' or family ' ' 

Low-grade or bran ' ' 
Bran, shorts, and waste 

(used principally for 

cattle food), 



55 lbs. 

15 " 

6 " 



24 



Graham Flour, or whole- wheat flour, is made from the unbolted meal 
of wheat, ground as finely as possible. It is actually a mixture of flour 
and bran. 

Composition of Common Flours. — The following analyses are col- 
lated and summarized from Bulletin 13, part 9 of the Bureau of Chem- 
istry: 



No. of 
Analy- 
ses. 


Moisture. 


Proteins, 
NX6.2S- 


Proteins, 
NX 5-70. 


40 
19 


12.77 
12.28 


10-55 
10.18 


9.62 
9.28 


14 


11.69 


12.28 


11.20 


3 

I 


12.57 
II. 41 


7-13 
13-56 




I 
I 


10.92 
11.89 


7-50 
8-75 





Moist 
Gluten. 



Dry 
Gluten. 



Patent wheat flour 

Common market wheat flour, 

Bakers' and family flour 

Indian-corn flour 

Rye flour 

Barley flour 

Buckwheat flour 



25-97 
24-55 
34-7° 



9-99 
9.21 

13-07 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



3^i 



Ether 
Extract 

(Fat). 



Patent wheat flour 

Common market wheat flour, 
Bakers' and family flour. ... 

Indian-corn flour 

Rye flour 

Barley flour 

Buckwheat flour , 




Ash. 



0.44 
0.61 

0-57 
0.61 

1-55 
0.86 



Nitrogen 

free Extract 

(Starch, 

Sugars 

Gums. etc.; 



Crude 
Fiber. 



74.76 
75-63 
73-87 
78.36 

73-37 
80.50 

75-41 



Calculated 
Calories of 
(Combus- 
tion. 



0.21 
0.28 
0.22 
0.87 
1.86 
0.67 
0.52 



3858 
3882 

3929 

3837 



3854 



Damaged Flour.— Grain is often damaged by the growth of smuts, 
rusts and ergot. Both grain and flour are also h'able to attacks of mold.s, 
yeasts, algae and bacteria. 

Various insects and other forms of animal life frequently infest either 
the grain or the flour, or both. Among the.se are weevils and various 
other beetles, flour moths, mites, and the wheat worm, a nematode related 
to trichina. 

Grain may also be damaged by sprouting, the diastase thus formed 
partially dissolving the starch granules with the formation of fissures 
and branching channels, which may be readily seen under the micro- 
scope. The amount of cold-water extract (page 320) shows to some 
extent whether or not a flour has been damaged. 

Ergot. — Ergot is a fungus growth that occasionally develops within 
the grain of r}'e and other cereals, and, unless care is taken, becomes 
ground with them in the preparation of meal and flour. Ergot contains 
alkaloids of a poisonous nature, and instances are on record of its acci- 
dental presence in cereal preparations causing serious injury to health. 
While most commonly fou:.d in rye, ergot occasionally grows in wheat. 
If flour or meal containing ergot be treated with a very dilute solution 
of anilin violet, the stain -..'ill be practically absorbed by the damaged 
particles of the grain, and resisted by the normal granules. If shaken 
with dilute alkali, a meal or flour contaminated with ergot is colored 
violet, which by treatment with acid lums red. A hot, alcoholic extract of 
flour containing ergot is colored red when treated with dilute sulphuric 
acid. 

Ergot in ground cereal preparations is best recognized under the 
microscope, appearing as a fine network of mostly colorless parenchyma 
cells, containing globules of fat (Fig. 67). Some of the cells are circular, 
others considerably elongated, and some contain a deep-brouTi coloring 



3^4 



FOOD INSPECTION AND /IN /I LYSIS. 



matter, which, when treated with ammonia, takes a violet-red color. 
Occasionally the cell walls appear of a dark color. If the suspected 
sample be treated with dilute anilin violet, as above described, the 
stained ergot fragments will be especially apparent under the micro- 
scope. 




,: j. 






A 




B 



Fig. 67.' — A, Transverse Section of the Ergot of \\Tieat under the Microscope; B Powdered 
Wheat Ergot. (After Villiers and Collin.^ 



Adulteration of Flour. — Besides the substitution of cheaper or in- 
ferior grades for those of higher quality, the fraudulent admixture of 
cereals, other than wheat, is not uncommon in Hour. Corn meal is some- 
times found as an adulterant of wheat flour. Its presence is best detected 
by the microscope, the difference between the wheat and corn starch 
being readily apparent. 

Rye flour is often adulterated with the cheaper grades of wheat flour 
or wheat middlings. This form of adulteration is detected by the Bamihl 
test (page 322) and by microscopic examination of the residue obtained 
after boiling with dilute acid (page 306). 

Much of the so-called buckwheat flour consists of mixtures containing 
wheat or corn flour, or both. Rice flour is also used in pancake flours, 
although probably to not cheapen the product. Self-raising pancake 
flours are usually mixtures of two or more flours with leavening material. 



CEREALS, LEGUMES, [VEGETABLES, AND FRUITS. 315 

The microscopic characteristics of the starch grains and tissues, serve 
to identify the different flours present in such mixtures. 

Finely ground mineral adulterants are said to have been used in flours, 
but no authentic instance of this kind has come to the writer's knowledge. 
Any considerable admixture of such a nature would be manifest in the 
increased ash. 

Alum in Flour. — -The addition of alum to flour was formerly a common 
practice in Europe, both by miller and baker, for the purpose of improv- 
ing the appearance of inferior or slightly damaged flour. Hence it was 
frequently found in the cheaper grades of flour and bread. Now, how- 
ever, it is rarely if ever used for this purpose, and the presence of notable 
quantities of alum or its compounds in flour or bread is usuallv due to 
its use as an ingredient of leavening powders. 

Detection. — To detect alum in flour, mix about 10 grams of the sample 
in 10 cc. of water and add about i cc. of an alcoholic tincture of logwood 
(5 grams logwood digested in 100 cc. alcohol) and about i cc. of a sat- 
urated solution of ammonium carbonate. Stir the whole well together. 
If the sample is pure, the color will be a faint brown or pink, but if alum 
is j)resent, a distinct lavender-blue color is produced, which should remain 
after heating for two hours in the water-oven. 

Alum may also be tested by the ammonium chloride method, described 
on jjage 344- 

Bleaching of Flour. — Within the past few years various processes 
for bleaching flour with nitrogen peroxide have come into extensive use 
both in Europe and America. The nitrogen peroxide is generated by 
electrical, chemical, or electro-chemical means, and is diluted with air 
before treatment of the flour. In the Alsop process, which is most 
commonly employed, the gas is formed by a flaming discharge of elec- 
tricity, which causes the nitrogen and oxygen of the air to combine. 

Nitrogen peroxide destroys almost immediately the yellow color which 
is associated with the fat of the flour, thus increasing the whiteness of the 
product. It also combines with the moisture of the flour, forming nitrous 
and nitric acids, the nitrous acid (free or combined) being especially 
noteworthy because of the ease of detection. Snyder, after conducting 
baking tests, reached the conclusion that the bread made from bleached 
flour does not contain nitrite-reacting substances; Ladd, Mitchell, and 
Winton, however, have found that when made by the usual methods it 
contains appreciable quantities, and certain results obtained by Alway 
bear out this conclusion. Bleaching also diminishes the iodine number 



3i6 FOOD INSPECTION /1ND ANALYSIS. 

of the fat of the flour, and is beheved by some to affect the quality of the 
gluten. 

Experiments of Shepard and of Ladd indicate that bleaching intro- 
duces toxic substances into the flour, although this is disputed by certain 
advocates of bleaching. Mitchell and also Winton find that bleaching 
injures the flavor of the bread. 

Secretary Wilson of the U. S. Department of Agriculture issued a 
decision on December 9, 1908, declaring the bleaching of flour with 
nitrogen peroxide to be illegal under the Food and Drugs Act of June 
30, 1906. 

INSPECTION AND ANALYSIS OF FLOUR. 

In some of the larger cities, authorized flour inspectors are appointed, 
whose business it is to examine the product and pass upon its quality. 
To such inspectors the local dealers submit samples, which the inspectors 
gauge as to color, soundness, weight, etc., comparing them usually with 
a series of graded samples, and stamping or branding them ofiicially 
with the date as well as the grade. Market quotations also -are based 
on the standard terms adopted. The names of the various grades differ 
with the locality. In St. Louis, the following names are adopted in order 
of their quality, viz.. Patent, Extra Fancy, Fancy, Choice, and Family. 

Such systems of inspection are under the auspices of local dealers, 
being organized and maintained for their own protection, and have not 
as yet been the subject of state or even municipal supervision, as in the 
case of meat inspection. The grade or quality of flour is determined 
largely by its appearance and color, by its fineness as indicated by rub- 
bing between the fingers, by its odor, and by the so-called " doughing 
test," which consists in kneading the flour with water under fixed con- 
ditions, and noting its tenacity and elasticity. Baking tests are also 
rehed on to a considerable extent by millers and buyers. 

Of the chemical methods employed in grading flour, those for the 
determination of ash, protein, and gluten are of chief importance. 

Fineness. — This is determined by rubbing the flour between the 
thumb and fingers. A gritty flour is one that is so coarsely ground that 
nt feels rough and granular. When treated with water on a glass plate, 
the individual granules are evident. Examined under the microscope, 
the coarse granules are seen to consist of aggregates of cells, the contents 
of which are still intact. Smooth flour, on the other hand, feels soft 
and slippery. It is so finely ground that the cells are isolated and often 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 317 

ruptured, a considerable part of the powder consisting of the starch 
grains and other cell contents, which have been liberated from the cells. 

Pekar's Color-test. — Place 10-15 grams of the tlour on a rectangular 
glass plate, about 12 cm. long and 8 cm. wide, and pack on one side in a 
straight line by means of a flour spatula. Treat the same amount of 
the standard flour used for comparison in the same manner, so that the 
straight edges of the two flours are adjacent. Carefully move one of the 
portions so as to be in contact with the other, and "slick" both with 
one stroke of the spatula, in such a manner that the thickness of the layer 
diminishes from about 0.5 cm. on the middle of the plate to a thin film 
at the edge, and the line of demarcation between the two flours is distinct. 
Cut oft' the edges of the layer with the spatula, so as to form a rectangle, 
and compare the color of the two flours. The dift'erence in color becomes 
more apparent after carefully immersing the plate with the flour in 
water, and still more apparent after drying. 

Absorption and Dough Test.— Stir 30 grams of the flour in a 
heavy coffee cup with 15 cc. of water by means of a spatula until a smooth 
ball of dough has been formed. If after standing two minutes the amount 
of water proves insuflicient to thoroughly dough up the flour, repeat 
the operation, using 15.5 cc. of water, and, if necessary, continue to 
repeat until the quantity is found that will yield a stiff, but thoroughly 
elastic dough. From the results of this test, calculate the absorption 
of 1000 grams of flour in terms of cc. of water. 

The physical characters of the dough, such as color and elasticity, 
furnish to the expert valuable indications of the quality or grade of the 
flour. 

Expansion of Dough. —Rub to a smooth paste 3.5 grams of granu- 
lated sugar, 1.2 grams of salt, and 3 grams of compressed yeast, and 
thoroughly mix with 60 cc. of wa*ter at 35° C. Warm 100 grams of the 
flour in a shallow pan to 35° C, add to it the yeast mixture, mix with a 
spatula, and knead with the fingers until a smooth ball of dough has been 
formed. Drop the dough into a graduated, 500 cc. cyhnder, pat down 
so as to force out the air, and note the volume of the mass. Place in a 
raising closet kept at 35° C. Read the volume at the end of the first 
hour and every half hour thereafter until the maximum is reached. 

Baking Tests.* — Koelners Method. — This process, also known as the 
straight dough method, yields a close-grained loaf of even texture, and 
serves well to determine the flavor and relative size of the loaf. 

* Descriptions by Miss H. L. Wessling, Chicago Laboratory, Bur. of Chemistry. 



3i8 FOOD INSPECTION AND ANALYSIS. 

Place 220 grams of the flour, previously warmed in a shallow pan, in 
a raising closet kept at 35° C, in a Koelner dough kneader, which has 
previously been warmed to 35° C. by means of water placed in the 
special compartment for this purpose. To the flour add 12 grams of 
sugar, 5 grams of salt, and 10 grams of compressed yeast, rubbed smooth 
and thoroughly mixed in a cup with 100 cc. of water at 35° C. Rinse the 
cup with suflicient water to make the total quantity required, as calcu- 
lated from the absorption test. This amount is usuafly about 87 cc. 

Adjust the blades of the kneader for mixing, and turn the crank at 
the rate of 90 revolutions per minute for 10 minutes. Adjust the blades 
for kneading, add 120 grams of flour, previously warmed to 35° C, and 
turn the crank for ten minutes at the rate of 60 revolutions per minute. 
Remove the dough immediately to a warmed plate, cut into two equal 
parts, mould the two separately, and place end to end in a warmed, 
greased, and tared baking tin measuring 27X6.3 cm. at the top, 25.4X5 
cm. at the bottom, and 8.8 cm. deep— all inside measurements. 

Weigh the tin with dough, place a tin gauge across the top, and set 
the whole in the raising closet. After the dough has risen to the gauge, 
place the tin in a suitable oven heated to 200° C, and bake at 200 to 
205° until 30 grams of water have been removed, which usually requires 
from 30 to 35 minutes. Break the loaf in two, and note the odor when 
hot and again when cold. 

When thoroughly cool, determine the volume of the loaf as follows: 
cover the bottom of a box 7.6X12.7X28 cm., inside measurements, with 
flaxseed, place the loaf in the box, pour flaxseed without jarring into 
the box until filled, and strike off the surplus seed by means of a straight 
edge. Remove the seed from the box, weigh, and divide the weight by 
the weight of i cc. of the seed, as calculated from an actual weighing of 
the seed required to fiU the box. Subtract this figure from the cubic 
contents of the box in cc, thus obtaining the volume of the loaf. 

Long Fermentation Method.— This method, used in some of the large 
mills in the northwest, differs from the Koelner method in that (i) a 
sponge is set, (2) the dough is kneaded twice, and (3) the dough is 
finally allowed to rise until it will allow no further expansion. The 
bread is coarse in texture, but serves well the purpose of determining the 
strength and flavor. 

To 255 grams of warmed flour contained in a jar or earthenware 
crock, add 3.5 grams of salt and 8.6 grams of compressed yeast, mixed 
thoroughly with 170 cc. of water at 35° C. Stir together until a soft 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 319 

sponge is formed, set in the raising closet, warmed to 35° C, and allow 
to rise until the volume has been doubled. Mix the risen sponge with 
85 grams of warmed flour, 12 grams of sugar, 6 grams of lard, and the 
remainder of water (the total quantity for 340 grams of flour being 
calculated from the absorption test). Knead steadily for 6 minutes, 
transfer the dough to the jar or crock, and set it in the raising closet until 
it has again doubled its volume. 

Remove the dough to a warmed plate, knead lightly in the hands for 
a minute or two, then place in a warmed, greased, and tared standard 
baking tin, which measures 16.8X8.8 cm. across the top, 14.9X6.9 cm. 
across the bottom, and 13.9 cm. deep, all inside measurements, and 
has wnngs or extensions of the metal at the top of the tw^o sides. 
Weigh the pan and dough, prick the latter about a dozen times with 
a fine pointed wire, and set again in the raising closet. Let it rise in the 
pan until the maximum volume has been reached, i.e., until the bubbles 
of gas just begin to break and form larger ones. This is a matter of 
judgment and can be learned only by experience. 

Since the dough always rises somewhat in the oven, it must not be 
raised to its limit beforehand, but must be put in the oven at such a 
stage that w^ith the additional rising in the oven it will have attained 
the maximum volume. A comparison of the volumes of different loaves 
will then be a means of judging the strength of the different flours. The 
loaf should be baked from 30 to 35 minutes, raising the temperature 
of the oven gradually from 180° C. at the beginning to 210° C. at the 
end. 

Determination of Proximate Constituents of Flour. — Moisture, 
ash, protein, crude fiber, and fat are determined by the usual methods 
(pp. 277 to 279). 

Determination of Moist and Dry Gluten.* — Place 25 grams of the 
flour in a coffee cup, add 15 cc. of water at a temperature not to exceed 
15°, and work the mass into a ball with a spatula, taking care that none 
of it adheres to the dish. Allow the dough to stand one hour, then knead 
in a stream of cold water over a piece of bolting cloth held in place by 
two embroidery hoops, until the starch and soluble matters are removed. 
Place the gluten thus obtained in cold water, and allow to remain for 
one hour, after which press as dry as possible between the hands, roll 
into a ball, place in a tared flat-bottomed dish, and weigh as moist 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 81, p. 118. 



320 FOOD INSPECTION AND ANALYSIS. 

gluten. Spread the gluten out in the dish, dry for 24 hours in a boiling 
water oven, and weigh again, thus obtaining the dry gluten. 

Determination of Alcohol-soluble Protein (Crude Gliadin). — 
Chamberlain' s Method.^ — Digest 5 grams of the sample with 250 cc. of 
7o9t (by vol.) alcohol for 24 hours, shaking every half hour during the 
first 8 hours. Filter through a dry paper, determine nitrogen in 100 cc. 
of the filtrate by the Kjeldahl or Gunning method, and multiply the 
result by 5.7. To facilitate evaporation, only 3 cc. of sulphuric acid 
are first used, the remainder being added after the solution has reached 
a small \olume. 

Determination of Salt-soluble Protein. — Chamberlain's Method* — 
Digest 12 grams of the flour with 300 cc. of 5% potassium sulphate 
solution, as described under Alcohol-soluble Protein. Determine nitro- 
gen in 100 cc. of the filtrate, and calculate the salt-soluble protein, using 
the factor 5.7. 

Determination of Acidity of Flour. — Titrate 100 cc. of the solution 
prepared as described for the determination of nitrites (page 321), with 
tenth-normal sodium hydroxide solution, using phenolphthalein as indi- 
cator. If the distilled water used contains an appreciable amount of 
carbon dioxide, it should be boiled previous to agitation with the flour. 

Determination of Cold-water Extract of Flour. — Wanklyn specified 
the following method of determining the cold-water extract. 

One hundred grams of the flour are thoroughly mixed with distilled 
water in a graduated liter-flask, which is finally filled with water to the 
mark; the contents are thoroughly mingled by frequent shaking during 
six or eight hours, and allowed to stand over night. The supernatant 
liquid is then poured upon a filter. After rejecting the first few cubic 
centimeters of the filtrate, exactly 50 cc. are collected and evaporated to 
dryness in a tared platinum dish on the water-bath. The weight of 
the dried residue, multiplied by 20, gives the quantity of cold-water extract, 
which, in a sound flour, according to Wanklyn, should not exceed 5%. 

Determination of Iodine Number of the Fat. — Place 20 grams 
of the flour (or a sufficient quantity to yield 0.2-0.25 grams of fat) in a 
dish of 100 mm. diameter, and dry in a desiccator over strong sulphuric 
acid for 3 days, thus removing the larger part of the moisture. Transfer 
the flour to the inner tube of a Johnson fat extractor, cover with a small 
amount of cotton previously extracted with ether, weigh down with a 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 8i, p. ii8. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 321 

piece of wide-bore glass tubing to prevent the rising of the flour in the 
extractor, due to expansion of ether in the lower end of the inner tube, 
and extract for 16 hours with 25 cc. of absolute ether into a tared 35 cc. 
flask. Drive off the larger part of the ether from the flask by gently 
heating, and dry to constant weight in the water or steam oven at 100° 
C, passing a current of dry hydrogen into the flask during the drying 
to avoid oxidation. As a rule 20 to 30 minutes' drying is sufficient. 
Reserve the flask and the contents for the determination of the iodine 
number. 

To the 35 cc. flask containing the fat, add 10 cc. of chloroform and 
25 cc of standard Hanus solution. Carefully place the flask, without 
removal of contents, in a saltmouth glass-stoppered bottle, and let stand 
one-half hour. Finally break the flask with a glass rod, add 10 cc. of 
potassium iodide solution and 100 cc. of water, and titrate with standard 
thiosulphatc solution. 

Detection of Bleaching in FIour.^The following simple tests serve 
to determine whether or not a given sample of flour has been bleached 
with nitrogen peroxide. 

Gasoline Test.^ — Place 25 grams of the flour in a 4 ounce, wide- 
mouthed, glass-stoppered bottle, add sufficient gasoline to nearly fill 
the bottle, shake, and allow to settle. If the flour is unbleached, the 
gasoline will be distinctly yellow; if bleached, it will remain nearly 
colorless. 

Nitrite Test. — Place 10 grams of the flour in a 4 ounce, wide-mouthed, 
glass-stoppered bottle. xA.dd 100 cc. of distilled water, and 4 cc. each 
of sulphanilic acid and alpha-naphtylamine chloride solutions, prepared 
as directed in the following section. Stopper the bottle and shake vigor- 
ously for a few minutes, then allow to stand for at least 30 minutes. If 
the flour is unbleached, the liquid will not be colored a red tint; if it is 
bleached, the liquid will take on a color ranging from light pink to deep 
red, according to the degree of bleaching. Always run for comparison 
a parallel test on a sample known to be unbleached, so that allowance 
can be made for any nitrites in the water. 

Determination of Nitrites in Flour. — Griess-Ilosvay Method. ■\^ 
This method, originally designed for the determination of nitrites in 
water, is well suited for the estimation of the extent to which flour has 
been bleached by nitrogen peroxide. 

* Based on observations of Alway. 

t Sutton, Volumetric Analysis, 9 Ed., p. 449. 



322 FOOD INSPECTION JND ^N^ LYSIS. 

1. Reagents. — (a) Sulphanilic acid solution. — Dissolve 0.5 gram of 
sulphanilic acid in 150 cc, of 20% acetic acid. 

(b) Alpha -naphtylamine chloride solution. — Dissolve 0.2 gram of the 
salt in 20 cc. of strong acetic acid with the aid of heat. Decant off the 
clear solution, and make up to 150 cc. with 20% acetic acid. 

(c) Standard sodium nitrite solution. — Prepare pure silver nitrite by- 
mixing a warm concentrated solution of 8 parts of sodium nitrite with a 
warm concentrated solution of 16 parts of silver nitrate. When cool, wash 
the precipitate with cold water, and dry quickly in a water bath with as 
little exposure to the light as possible. Dissolve 0.1097 gram of the dry 
silver nitrite in warm water, add a slight excess of pure sodium chloride, 
and make up to 1000 cc. After the silver chloride has settled, draw 
off 10 cc. of the clear solution, and dilute to one liter. One cc. of this 
solution contains o.oooi mg. of the nitrogen as nitrite. 

2. Deierminatian. — Weigh out 25 grams of the flour (or of the 
crumbled bread) into an Erlenmeyer flask, add 250 cc. of water free 
from nitrites, shake vigorously for five minutes, let stand for one-half 
to one hour, and filter on a paper free from nitrites. Make 50 cc. of the 
filtrate up to 100 cc. with water, and add 2 cc. each of sulphanilic acid 
solution and naphtylamine chloride solution, shake, and heat at about 
80° C. for 10 minutes to bring out the color. 

For comparison, dilute 50 cc. of the standard sodium nitrite solution 
to 100 cc, and treat with sulphanilic acid and alpha-naphtylamine chloride 
solutions, as above described. Compare the solutions to be tested with 
this solution in a colorimeter, and calculate the parts of nitrogen as 
nitrite per kilo of flour or bread. In flours containing above 3 mgs. per 
kilo, make 10 cc. (instead of 50 cc.) up to 100 cc, thus avoiding the 
intense red color obtained in a more concentrated solution, 

Bamihl Test for Gluten {Modified by Winton*). — This test serves 
to detect wheat flour mixed with rye and other flours. 

Place a very small quantity of the flour (about 1.5 milligrams) on a 
microscope slide, add a drop of water containing 0.2 gram of water- 
soluble eosin in 1000 cc, and mix by means of a cover glass, holding the 
latter at first in such a manner that it is raised slightly above the slide, 
and taking care that none of the flour escapes from beneath it. Finally 
allow the cover glass to rest on the slide, and rub it back and forth until 
the gluten has collected into rolls. The operation should be carried 
out on a white paper so that the formation of gluten can be noted. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 217. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 323 

Wheat flour or other flours containing it yields by this treatment a 
copious amount of gkiten, which absorbs the eosin with avidity, taking 
on a carmine color. Rye and corn flour yield only a trace of gluten, and 
buckwheat flour no appreciable amount. The preparations are best 
examined with the naked eye, thus gaining an idea of the amount of 
gluten present. Under the microscope traces of gluten, such as are 
formed in rye flour, are so magnified as to be misleading. 

In case the flour is coarse, or contains a considerable amount of bran- 
elements, as is true of buckwheat flour and low grade wheat flour, the 
test should be made after bolting, as the bran particles and coarse lumps 
interfere with the formation of gluten rolls. 

BREAD. 

Bread is a term broadly applied to any baked mixture of finely divided 
grain and water, whether or not other ingredients are used. Pilot, or 
ship bread, crackers, and unleavened bread, consist almost entirely of 
flour and water with a shght addition of salt. 

Similarly, corn bread or corn cake is frequently made exclusively from 
corn meal and water. In a narrower sense, however, bread is generally 
understood to mean the raised or leavened product, rendered light and 
porous by the aid of gas, which is generated either before or during baking. 
Commonly the gas employed is carbon dioxide, generated either by the 
fermentative action of yeast on the sugar of the dough, yielding both 
alcohol and gas, or by the agency of baking chemicals mixed with the 
dough, whereby an alkaline bicarbonate is decomposed by the action 
of an acid to produce the gas. Again, the gas may consist wholly or in 
part of ammonia, yielded by the vaporization during baking of ammo- 
nium carbonate mixed with the dough; and finally, the expansion dur- 
ing baking of the air itself confined in the dough may be the leavening 
agent, as in the case of puff paste and pie crust. 

Wheat' flour is of chief value for bread on account of its high content 
of gluten, in which other cereals are lacking. In the preparation of 
ordinary white bread, the flour is mixed with water or milk, salt, and yeast, 
the materials are mingled thoroughly by kneading and allowed to remain 
for some time in a warm place, during which, by the vinous fermentation 
induced by the yeast, the mass "rises" or forms a light sponge, due to 
the action of the gas on the glutinous dough. 

During the subsequent process of baking, which should take place at 



S^i 



h()()l> INSrr.CTION AND .IN.n.YSlS. 



a lempcralurc l)clvv('cn 230° and 260° C, fuilhcr expansion ensues, much 
of the water is driven off, and the porous mass sets to form Ihc loaf, the 
outside of whi( h is (()nvert(;d into a brown crust, due to the carameli/ing 
of the dextrin ;iii(l siii',;ir iiilo vvhi( li the starch of Ihc outer layers is eon- 
verleil. Amon;.!; other ( lianjM-s I hat take pla(c in the interior or "crumb" 
d'lring 1)aking are (ij the partial brcakini!; up of the starch grains, wiiich, 
however, largely retain Ihcir idcnl il), though in some degree distorted in 
shape; („') somewhat obsc me change-; in the character of the- prolc-ins; 
and (3) partial oxidation of the c)il or fat. 

The statidard for judging the cpialily of commercial bread may we'.l 
be based on ihal of ihc- best home baked famil}' loaf. 'I"he well-made 
loaf should possc-ss an agreeable odor, and a sweet, nully llavor, entirely 
free from nuisliness. ll should be well "raised," with a good crumbling 
fracture; it should noi be lough or soggy on the one hand (due lo under- 
raising), nor extremely dry and s])ongy on ihe other (indicative of over- 
raising). < )\c'r raising, moicover, produces sourness, clue lo advanced 
lactic fermenlalion. 

Composition of Bread.- 'i"he following analyses made in I he U. S. 
ibucau of Chemislr^' of connnon \arielies ol bi'eacl were sunuuarized 
from Ihillelin 1,:;, pari c;, .iver.iges of a number of analyses being given in 
each case: 



N... c.f 
Amvlyses. 



Mi)i8ture. 



I'rotcin, 
NX6.as. 



Protein, 
NX5-70. 



Ether 
Extract. 



Vicnnii lircii'l 

lloiiii" in;;(lc' l)ic-;i(l . 

('■lali.un l)n',i(l 

Kyc- l.rcad 

Klisc c-lliuu-(Uis i)ir;i<l 
Miscuils or cracltcrs. 
Rolls 

Vicntiii lircad 

1 Inmc maiic l)rc:ul . 

( iraham in-rad 

Kyc lin-ad 

Mis( rli.-iiu'oiis hicad 
Hist iiits or ( rai kcis 
Roils 



,^,^■l-■ 

7-',< 
2 7.(>S 



8.87 
7-<).| 
S.„,^ 
8.<>.< 
7. do 
10., <4 
8.20 



8.0() 

7 - -^-l 
8.1s 
7.88 

7.48 



1 .06 

1-95 
2.0,^ 
o.6() 
J. 48 
8.67 
3-41 



Crude 

FilHT. 



0.62 

0.24 

'•',S 
0.62 
0.30 
0.47 
o.do 



Salt. 



0-57 
o.5() 

0.()() 

1 .00 
0.41) 

O.C)() 

o . U) 



Ash. 



T.lf) 

1 .05 

i.S<) 
1.84 
1 .00 

'•3' 



Carhcihv- 
ilratc-s, 

ICxi'linliuK 
I'-ibiT. 



53-72 
5'' -75 
53 --10 

5f).2 1 

5'). 18 

73-17 
5c;. 8 2 



CaK'ulatcil 

Caliiricsot" 

Cnnihus- 

ti(jn. 



4435 
4467 

4473 
4338 
4429 
4755 
4538 



In the examination of ])read for its gc-neral (|uality, without regard to its 
food value, much information may be gained by carefully observing the 



CERH/ILS, LEGUMES, VEJ.ETAHI.ES, AND I HUITS. 



325 



physical characteristics of the loaf, its color, taste, ocJor, porosity, etc. 
In addition to such data, determination of moisture, ash, and acidity 
will usually suffice to enable the analyst to pass judgment on its whole- 
someness. The following summary gives such analytical data on 
upwards of fifty samples of bread, purchased from cheaper bakeries 
and stores, and examined in the author's laboratory. 

BREAD. 



Kind of Ur'-ad. 


No. of 
Analyses. 


Weight of 
Loaf in 
Grams, 


Water, 
Per Cent. 


Percent 
Ash in 

Terms of 
Solids. 


Acidity.* 


White 


44 

7 
1 








.Maximum 


653 
126 

430 

500 

367 
420 

507 
445 
194 
1291 
550 
417 
500 
no 


45.20 

33-00 

40.72 

45.20 
40.10 
41.50 
45.10 
47.00 
48.20 

47-15 
47.00 
42.30 
48.10 
8.00 


1.83 
0,60 
0.85 

1-55 
0.96 
1.26 
1.20 
2.20 

I-I5 
2.13 
2.20 
0-95 
3-50 
1-94 


fj 2 


Minimum 


1-3 
2.6 


Mean 

Graham 


Maximum 


4-2 


-Minimum 


.Vlf-an 


3-5 


Whole wheat 


Oiabetic 


I 
I 

I 
I 

I 




Muffins 


1.7 


kve 


"iilaflc" 




f icrman with seed.s 




firown 


I 
I 




" Knackerbrod" 





* CuVjic centimeters of tenth-Ti'jrTnul vAa. required to neutralize 10 grams of the fresh bread. 



Water in Bread.^ — The amount of water is of considerable importance, 
and, in the best bread, varies from t,t^ to 40 per cent. A larger content of 
water than 40% should be considered objectionable in a white bread, 
both on the ground of acting as a make weight, and because a large excess 
of moisture tends to cause the growth of mold. 

Acidity of Bread. — The degree of sourness of a sample of bread is one 
of the most important indications as to its quality, and is most readily 
obtained by rubbing up in water, by means of a pestle, to grams of the 
" crumb," and titrating with tenth-normal alkali, using phenolphthakin 
as an indicator. To neutralize the acidity of 10 grams of the normally 
sweet loaf, an average of 2 cc. of the standard alkali solution is required, 
corresponding to 0.72 gram of lactic acid jx.r loaf of an average weight 
of 400 grams. The loaf exhibiting the maximum sourness or acidity 
in the above table required 10 cc. of standard alkali per 10 gram.-, of 
bread, corresponding to 11. 61 grams lactic acid in the loaf of 1,291 gram.s. 



326 FOOD INSPECTION AND ANALV^IS. 

Fat in Bread. — It is well known that the results of fat or ether extract 
as obtained by the ordinary method and expressed in most bread analyses 
are too low, being considerably less than the combined fat of the materials 
entering into its composition. This is probably due to the fact that 
during baking the fat particles are incrusted with insoluble matter, 
which protects them from the subsequent action of the ether. It is further 
claimed by some that the partial oxidation of the fat during baking 
has something to do with the low results. No perfectly satisfactor)' 
improvement over the regular ether method for fat extraction in bread 
has been discovered, and therefore this method, as described elsewhere, 
is recommended. 

Adulteration of Bread. — The fraudulent addition of inert foreign 
ingredients to bread is almost never practiced, and is mainly of historic 
interest. Gypsum, chalk, bone ash, and various other minerals have been 
mentioned as possible adukerants, but the amount of any of these 
materials necessary to add for purposes of profit could scarcely be present 
without very apparent injury to the quahty of the bread. Their presence 
in any considerable degree would be apparent in the abnormally high 
ash content of the bread. 

The employment of alum to "improve" inferior or unsound flour 
has already been referred to, and, for the same purpose, sulphate of copper 
in small quantities is also said to have been used," enabling the making 
of bread of fairly good appearance from flour that was distinctly damaged. 

Alum in Bread * is tested for by a modification of the logwood process 
described on page 315 as follows: 5 cc. of the logwood tincture and 5 cc. 
of the saturated ammonium carbonate solution are diluted to 100 cc, 
and the freshly prepared mixture poured over about 10 grams of the 
bread crumbs in a porcelain evaporating-dish. After standing a few 
minutes, as much as possible of the hquid is drained off, the bread is 
shghtly washed by one treatment with water, and dried in the water- 
oven. In presence of alum, a dark-blue color is given to the bread, which 
becomes deeper on drying. The color is proportional to the amount 
of alum present. If the sample is free from alum, the color varies from 
red to light brown. The reagent solution must be freshly prepared. This 
test is not perfectly reliable in the case of very old or sour breads, which 
have been known to give the color test with logwood in the absence of 
alum. 



* Jago on Bread, p. 634. 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 



327 



Copper Salts in Bread are detected in the ash by the same method 
as that used for canned goods (p. 902). 

Cake and Similar Preparations. — These differ from bread chiefly by 
the addition of considerable sugar, butter, spices, and other flavoring 
materials. In gingerbread, molasses is used as an important ingredient 
besides ginger. The adulterants of molasses, such as glucose, salts of 
tin, etc., would thus sometimes occur in gingerbread. In fact stannous 
chloride has been found in ginger cakes.* 

The following analyses of a few typical varieties of cakes are selected 
from Bulletin 13 of the Bureau of Chemistry: 



Moisture. 



Proteins, 

NX6.25. 



Proteins, 

NX5.70. 



Ether 
Extract. 



Crude 
Fiber. 



Doughnuts . . 
Ginger snaps 

Fruit cake 

Gingerbread. 

Cup cakes 

Macaroons . . 
Jumbles 



21.61 
4.86 
24.47 
21.49 
14.81 
8.06 
13-34 



6.73 
6.06 

4-56 
6.25 

5-24 
6.67 
7.62 



6.14 

5-53 
4.16 

5-70 
4.78 
6.08 

6-95 



19-33 
15-44 

12.35 
8.42 

15-56 
12.97 
14.79 



0.60 
0.79 

0.90 
0.27 
1. 41 
1.04 



Ash. 



Salt. 



Sugar. 



Carbohy- 
drates 
other than 

Fiber and 
Sugar. 



Calculated 
Calories. 



Doughnuts . . 
Ginger snaps. 
Fruit cake. . . 
Gingerbread. 

Cup cakes 

Macaroons . . 
Jumbles 



40 





03 


82 





■47 


55 





28 


21 





34 


82 





07 


97 





39 



28.66 

9.48 
32-48 

58-77 

16.60 



50.64 
24.90 

52.46 
30.89 

10.89 

46.31 



5529 
4971 

4757 
5073 
4835 
5133 



YEAST. 

The yeast plant is a fungus of the genus Saccharomyces, widely 
distributed through the vegetable kingdom and in the air. It is capable 
of rapid growth by the multiphcation of its cells when present in a 
favorable medium, such as malt wort, and with propitious conditions 
of temperature, moisture, etc. Under such conditions, it forms a 
yellowish, viscous, frothy substance, the chief value of which, in the liquor 
industry, is the production of alcohol, while for bread-making, as a result 
of the same kind of fermentation, the end desired is the leavening of the 
doughy mass by the carbon dio.xide liberated. 



* See U. S. Dept. of Agric, Bur. of Chem., Bui. 13, p. 1369. 



32S ronn iNSfucrioN /inij an/ilysis. 

A vij^orous, pure yeast which will "raise" quickly is a great preventive 
against sour bread, for not only is it comparatively free from the germs and 
j;ro(lucts of lactic acid fermentation, but by doing its work (juickly it 
enables I he baker lo (heck the fermentation or raising process before the 
lactic acid or sour decomposition is far advanced. 

Yeast most commonly used in bread-making is of the so-called " com- 
pressed" variety. The use of compressed yeast is almost universal for 
domestic purjjoses, and is more or less common in bakeries. A small 
amount of brewers' yeast in liquid form from beer wort is used, especially 
in Ihe immediate neighl^orhood of breweries, and dry yeasts are used to 
some extent in localities so remote that fresh comjiressed yeast cannot 
rea(h'ly be obtained. 

Compressed Yeast is a pnnluct ui distilleries where malt and raw 
grain are fermented for spirits. Most of it comes from whisky wort, and 
some from the worts used in the manufacture of gin and other distilled 
li(juors. Little if any of the commercial comj)ressed yeast is made from 
beer wort yeast. 

In lh(,- in.inufacture of comj)ressed yeast, the yeast floating on the lop 
of the wort is se])arated l^y skimming, while that settling to the bottom 
is removed by running the wort into shallow settling trays. Top yeast 
is considered more desirable than bottom yeast for bread-making. The 
separated yeast is washed in cold water, and impurities are removed, 
either by sieving through silk or wire sieves, or by fractional precipitation 
while washing. The yeast, with or without the addition of .starch, is 
i'mally pressed in bugs in hydraulic })resses, after which it is cut into cakes, 
j)ackcd in tin foil, and kept in cold storage till distributed for use. 

Such yeast should be used when fresh, as it readily decomposes and 
soon becomes stale. When fresh, it should have a creamy, white color, 
uniform lliroughout, and should possess a fme, even texture; it should 
be moist without being .slimy. It should (juickly meU in the mouth 
without an acid taste. Its odor is characteristic, and should be some- 
what suggestive of the apple. It should never be "cheesy," such an 
odor indicating incipient decomposition, a.s does a dark or streaked color. 

Dry Yeast is ])repared by mixing fresh yeast with starch or meal, 
molding into a stiff dough, and drying, either in the sun or at a moderate 
temj)crature under reduced ])ressure. Such yeast, when dry, is cut into 
cakes and put in ])ackages. It will keep almost indefmitely. During 
the drying process, many of the yeast cells are rendered torpid and tem- 
porarily inert, and for this reason the dried yeast does not act so promptly 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 329 

in leavening as does compressed or brewers' yeast, but when once it begins 
to act it is quite as efficacious. 

Composition of Yeast. — The following is the result of the analysis 
of under- fermentation yeast, after drying, by Nagele and Loew: 

Cellulose and mucilage 37 

Albuminoids (mycroprotein, etc.) 36 

" soIuVjle in alcohol 9 

Peptones (precipitable by subacetate of lead j ... 2 

Fat 5 

Extractive matters (leucin, glycerin, etc.) 4 

Ash 7 

100 

Lintner gives the following average analyses of the ash of three samples 
of yeast, analyzed by him: 

Silica T .34 

Iron (FcjOj) o . 50 

Lime (CaO j 5.47 

Sulphuric anhydride fSOj) o. 56 

Magnesin (MgO ) 6.12 

Phosphoric anhydride fPjOjj 50.60 

Potash (K2O) and a little soda 33-49 

98.08 

Matthews and Scott give the following as the ash composition of yeast: 

Potassium phosphate 78. 5 

Magnesium phosphate 13.3 

Calcium phosphate 6.8 

Silica, alumina, etc 1.4 

loo.o 

Microscopical Examination of Yeast. — Mix a bit of the yeast in water 
on the glass slip till a mill<y fluid is formed, and stir in a drop of a 
very weak anilin dye solution, such as methyl violet, eosin, or fuch- 



330 FOOD INSPECTION AND ANALYSIS. 

sin.* Put on the cover-glass, and examine under the microscope. 
Living, active cells resist the stain, if the latter is dilute enough, and 
appear colorless or nearly so, while the decayed and lifeless cells are 
stained, and can easily be distinguished by their color. Yeast cells are 
circular or oval in shape, and vary from 0.007 to 0009 mm. in diameter. 
They are sometimes isolated, and sometimes grouped in colonies; each 
cell has an outer, mucilaginous coating or envelope. The interior, granu- 
lar mass or substance of the cell is the protoplasm, and within the 
protoplasm are frequently seen one or more circular empty spaces 
known as vacuoles. 

Yeast cells multiply by the process of budding. The decadence of 
yeast cells is marked by the increased size of vacuole, and by the thicken- 
ing of the cell wall. 




'6^^ 



a b 

Fig. 6S. — Sprouting Yeast-cells {Saccharomycss cerevisice). (a, after Liirssen; b, after 

Hansen.) 

Yeast-testing. — Available Carbon Dioxide. — The value of yeast in 
bread-making depends on the amount of carbon dioxide which it is capa- 
ble of generating under given circumstances, hence the available carbon 
dioxide is the chief factor in gauging a yeast. There are various methods 
of determination, (i) either by measuring the volume of gas set free by 
the action of a weighed quantity of yeast in a sugar solution of known 
strength, kept for a fixed time at a fixed temperature (say 30°), or (2) 
by conducting the gas from such a fermenting solution through a weighed 
absorption bulb, containing potassium hydroxide and noting the increase 
in weight, or (3) by the more convenient method of Meissl as follows: 

A mixture is made of 400 grams pure, concentrated sugar, 25 grams 
ammonium phosphate, and 25 grams potassium phosphate. A small, 
wide-mouthed flask of about 100 cc. capacity is fitted with a doubly per- 
forated rubber stopper, having two tubes as shown, one of which is bent 
and passes nearly to the bottom of the flask, being fitted at the outer 
end with a rubber tube and glass plug, while the other is connected with 
a small calcium chloride tube. Measure 50 cc. of distilled water into 

* I gram crystallized fuchsin in i6o cc. water having i cc. alcohol. 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 



331 




this flask, and dissolve 4.5 grams of the above sugar phosphate mixture. 
Finally add i gram of the yeast to be tested, stir it well till there are no 
lumps, and cork the flask. Carefully weigh on a 
dehcate balance the flask with its contents, and 
immerse in a water-bath at 30° C, keeping it at 
that temperature for six hours. At the end of 
this time, remove the flask from the bath, and 
immediately immerse in cold water to cool the 
contents. Remove the rubber tube with the glass 
plug, and by suction draw out the remaining carbon 
dioxide. Replace the plug, and ha\'ing carefully 
wiped off the flask, again weigh. The loss in 
■weight is due to carbon dioxide set free by the fer- 
mentation of the yeast. 

Starch in Compressed Yeast. — The addition of 
potato starch to yeast before pressing has long been 
customar}-, on the grounds that the starch acted as 
a drier, producing a much cleaner product, and 
one that could be more readily and intimately 
mingled with the materials of the bread, besides 
enhancing the keeping quahties of the yeast, es- 
pecially in warm weather. The best grades of compressed yeast contain 
about 5^ of starch, but some are found with 50^ and even more. Un- 
doubtedly the larger amounts are added as a make weight. 

The question has frequently been raised whether, with improved 
methods of manufacture, whereby yeast could be produced comparatively 
free from shme, and thus capable of pressure without the admixture of 
starch, the use of the latter should not be considered as an adulterant. 
Some of the compressed yeast on the market is free from starch, and its 
makers claim that this is the only absolutely pure variety, while the presence 
of starch should be distinctly regarded as a violation of the section of the 
food law which forbids the use of a cheaper or inferior ingredient. 

Briant claims that the admixture of starch up to 59c increases rather 
than decreases the actual content of yeast, in that the starch abstracts 
moisture from the yeast cells themselves, the proportion of water being 
much smaller, and that of the yeast larger in the starch-mixed substance. 
T. J. Bryan,* on the other hand, finds that the addition of starch to yeast 
reduces the carbon dioxide value, and that the percentage reduction is 
greater than the percentage of starch present. His experiments further 



Fig. 6f). — Apparatus for 
Determining Leaven- 
ing Power of Yeast. 



* A. O. A. C. Proc. 1907, U. S. Dept. of Agric, Bur. of Chem., Bui. ii6, p. 25. 



332 FOOD INSPECTION AND ANALYSIS. 

indicate that the keeping qualities of starch yeast is not greater but actually 
less than that of pure yeast. 

In the absence of a legal standard for starch in yeast, it is difficult 
to see how complaints could be maintained under the general food laws 
of most states, without condemning the use of starch altogether. 

Jago suggests 20% as the limit for starch in yeast, beyond which it 
should be considered as an adulterant. 

CHEMICAL LEAVENING MATERIALS. 

Under this heading are included the various ingredients that enter 
into the mixtures commonly known as "baking powders" which have 
no food value in themselves, but are, strictly speaking, instruments or 
tools that by purely chemical reactions bring about, under certain con- 
ditions, the comparatively quick hberation of gas and the consequent 
aeration of biscuit, bread, and cake. 

Baking Powders and their Classification. — Formerly the housewife 
was accustomed to measure out in proper proportion a mixture of sour 
milk, or cream of tartar, with saleratus to produce quick aeration of bread. 
The modern baking powder is a natural outgrowth of the former practice, 
and has almost wholly displaced it, producing, as it does, a mixture ready 
for immediate use of an acid and an alkahne constituent in proper pro- 
portion for chemical combination to form the gas. A third ingredient 
is, however, generally considered as necessary to check deterioration, 
viz., a dry, inert material, which by absorbing moisture prevents the pre- 
mature chemical action between the reagents. Starch is nearly always 
used for this purpose, though sugar of milk has a limited use. The alkaline 
principle of nearly all baking powders is bicarbonate of soda, or saleratus. 
Baking powders are divided naturally into three main classes, with refer- 
ence to the acid principle: 

(i) Tartrate Powders, wherein the acid principle is {a) bitartrate of 
potassium or (6) tartaric acid, typified by the following reactions: 



188 84 210 44 18 

(a) KHQHPe+ NaHC03 = KNaC,H,Oe+ €0,+ H,0 

Water 



Potassium 


Sodium 


Potassium 


Carbon 


bitartrate 


bicarbonate 


and sodium 
tartrate 


dioxide 



150 168 230 ^2> 

{h) H,cXOe+ 2NaHC03 = Na.C,H,Oe.2H20+ 2CO, 

Tartaric Sodium Sodium tartrate Carbon 

acid bicarbonate '''oxide 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. ^t^t^ 

(2) Phosphate Powders, in which calcium acid phosphate is the acid 
principle : 

234 168 136 142 88 36 

CaHJPOj2+2NaHC03 = CaHPO,+Na2HPO,+ 2CO,+ 2H,0 

Calcium Sodium Calcium Disodium Carbon Water 

acid phos- bicarbonate monohy- phosphate dioxide 

phate drogen phos- 

phate 

(3) ''Alum Powders,'" wherein the acidity is due wholly or in part 
to sulphate of aluminum as it occurs in potash or ammonia alum, or in 
the double sulphates of aluminum and sodium.* 

Assuming burnt potash alum as the substance used, the reaction 
would be as follows: 



516 504 156 426 174 264 

KjAljCSO,),-}- 6NaHC03=Al,(OH)6+ 3Na,SO,+ K^SO^-f 6CO2 

Burnt pot- Sodium Aluminum Sodium Potassium Carbon 

ash alum bicarbonate hydrate sulphate sulphate dioxide 

Naturally many baking powders of complex composition are met 
with, embodying various mixtures of the above classes. 

Composition of Various Baking Powders. — Following are analyses 
of typical baking powders of the above classes: t 

I. Cream of Tartar Baking Powder: 

Total carbon dioxide, CO2 13 • 21 

Sodium oxide, Na20 13-58 

Potassium oxide, K^O 14-93 

Calcium oxide, CaO .18 

Tartaric acid, C4H4O5 41 .60 

Si'lpliuric acid, SO3 .10 

Starch 7.42 

Water of combination and association by difference. . . 8 . 98 



100.00 
Available carbon dioxide 12.58%. 

* It is probable that very little ammonia or potash alum is actually used at present in 
this class of powders. A product largely used is known in the trade as C. T. S. (cream of 
tartar substitute) and is a calcined double sulphate of aluminum and sodium. 

t Div. of Chem., Bui. 13, part 5, pp. 600, 604, and 606. 



334 FOOD INSPECTION AND ANALYSIS. 

2. Phosphate Baking Powder: 

Total carbon dioxide, CO, 13-47 

Sodium oxide, Na^O 1 2 . 66 

Potassium oxide, KjO 31 

Calcium oxide, CaO 10.27 

Phosphoric acid, P.Oj 21.83 

Starch 26.41 

Water of combination and association by difference. .. 15-05 

100.00 
Available carbon dioxide 12.86%. 

3. Alum Baking Powder: 

Total carbon dioxide, CO2 9.45 

Sodium oxide, NajO 9-52 

Aluminum oxide, AI2O3 3 . 73 

Ammonia, NH3 1.07 

Sulphuric acid, SO3 10.71 

Starch 43-25 

Water of combination and association by difference . . 22.27 



100.00 
Available carbon dioxide 8.10%. 

Mixed Powders: 

Total carbon dioxide, CO. 10.68 

Sodium oxide, NajO 14.04 

Calcium oxide, CaO i . 29 

Aluminum oxide, AI2O3 4.59 

Ammonia, NH3 i . 13 

Phosphoric acid, P2O5 3 .38 

Sulphuric acid, SO3 ii-57 

Starch 42 - 93 

Water of combination and association by difference . . 10 . 39 



100.00 
Available carbon dioxide 10.37%. 

The Adulteration of Baking Powder. — No substance that comes 
within the domain of food inspection is the subject of so much controversy 



CEREALS, LEGUMES, yEGETABLES, /1ND FRUITS. 335 

as baking powder. Unless a specific law forbids the use of a particular 
ingredient or class of ingredients, or in some manner regulates the 
labelling of the package, no baking powder of any kind can be considered 
adulterated under the general food law, unless it can be proved lo be 
injurious to health, or unless it contain inert and useless mineral matter. 

As a matter of fact, the residue left in the bread Vjy all classes of baking 
powder consists of one or more drugs recognized in the Pharmacopoeia, 
all of which in large quantity exercise well-marked toxic effects on the 
human system. Artificial digestion experiments, and physiological tests 
on the lower animals, using excessive doses of any of the above drugs, do 
not show the effect of the ever}^-day use of baking powder in bread on the 
human system, and only a systematic examination of the efifect of such 
use on large numbers of people can prove conclusively whether or not any 
one class of baking powders is harmful, and hence whether or not it 
should be classed as adulterated. Aside from the question of the harm- 
fulness of the acid ingredients employed in baking powder, which is the 
subject of much controversy among rival manufacturers, there can be 
no doubt that such inert make weight substances as calcium sulphate, 
or terra alba, or clay, which are entirely useless, and lower the strength, 
quality, and purity of the powder, are to be considered in the hght of adul- 
terants. 

Cream of Tartar — Its Nature and Adulteration. — Cream of tartar, 
or potassium bitartrate (KH5C40e), is the purified product obtained by 
the recrj^stallization of the crude argols or lees deposited in the interior 
of wine casks. 

The lees, or argols, consist chiefly of crude potassium bitartrate, which 
is present in the juice of the grape, but is insoluble in the alcohol formed 
in the fermentation, and is hence deposited. If, for the clarification of 
the wine, such substances as gypsum or plaster of Paris are used, tar- 
trate of calcium will be found mixed with the bitartrate of potassium in 
the lees. Hence it is that calcium tartrate is sometimes found in commer- 
cial cream of tartar. 

Potassium bitartrate is insoluble in alcohol, sparingly soluble in cold, 
and readily soluble in hot water. 

Allen * states that when the calcium tartrate is present in excess of 10%, 
it should undoubtedly be considered as an adulterant. 

Other common adulterants of cream of tartar are calcium acid phos- 
phate, g}'psum, or plaster of Paris, starch, and alum. 

* Analyst, V, 1 14. 



336 FOOD INSPECTION AND ANALYSIS. 



CHEMICAL ANALYSIS OF BAKING CHEMICALS AND BAKING POWDERS. 

Cream of Tartar. — The degree of purity of commercial cream of 
tartar is best determined by weighing out exactly 0.188 gram of the 
sample, dissolving in hot water, and titrating with tenth-normal sodium 
hydroxide, using phenolphthalein as an indicator. If the article is pure, 
exactly 10 cc. of the standard alkali will be required for the titration. All 
the above-named adulterants, with the exception of alum, are either insol- 
uble, or sparingly soluble in hot water, and will indicate the impurity of 
the sample even before titration. If the adulterant be alum, the sample 
would go into solution in the water, but the alum would be precipitated 
by the sodium hydroxide, the precipitate being, however, soluble in an 
excess of the alkali. 

Sodium Bicarbonate on account of its cheapness is rarely adulterated, 
save by the occasional presence of common salt, an impurity incidental 
to its manufacture. The degree of purity of sodium bicarbonate is best 
ascertained by titration with standard acid, each cubic centimeter of tenth- 
normal acid being equivalent to 0.0084 gram of sodium bicarbonate. 

Determination of Total Carbon Dioxide. — Reagents. — Calcium 
Chloride. — This can be obtained in granulated form in pellets of abc ut 
the size of peas, specially prepared for moisture absorption. 

Soda Lime* — ^To a kilogram of commercial sodium hydroxide, 500 
to 600 cc. of water are added, and the mixture heated in an iron kettle 
to form a thin paste. While still hot, a kilogram of coarsely powdered quick- 
lime is added, stirring with an iron rod. The lime is slaked, and the whole 
mass heats and steams up. No outside heat is necessary at this stage, 
but the mass is stirred and the lumps broken up. As soon as cool, place 
the product in wide- mouthed bottles, and seal with paraffin wax. The 
product should be slightly moist to give the best results. 

Hydrochloric Acid. — Specific gravity i.i. 

Sulphuric Acid. — Specific gravity 1.85. 

Potassium Hydroxide Solution. — Specific gravity i.55« 

Two varieties of apparatus are in use for the d_ termination of carbon 
dioxide. In one form the amount of carbon dioxide is obtained by dif- 
ference in weight of the apparatus, before and after eHmination of the 
gas. In the other, the gas driven out of a given weight of the sample is 
absorbed, and its amount calculated from the increase in weight of the 

* Benedict and Tower, Jour. Am. Chem. Soc, VoL XXI, p. 396. 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 



337 



absorbent. Types of these varieties are the Geissler and the Knorr 
apparatus 

The Geissler Apparatus. — This consists of a flask A, having a ground 
neck a, and a flaring funnel-top A\ B is an elongated bulb, closed at the 
top by the hollow stopper K, and terminating below in the hollow stem 
B' . which is accurately ground at b to fit the neck a. Fused into the 
bulb B is the tube C, and within this is the small tube D, open at the top 
and communicating directly "vsith the hollow stem 
B'. gg are openings between B and C. 

£ is a fine glass tube, passing from the bottom 
of the hollow stem 5' and to the height of a small 
protuberance e in the bottom of the funnel A', the 
construction being such that by turning the bulb 
and stem BB' in the neck a of the flask A the 
tube E may be opened or closed at the top. H 
is a side tube in the flask A, closed by the ground 
stopper h. 

The bulb B and the tube C are fifled with 
strong sulphuric acid nearly to the top of the tube 
D, by passing through the neck at the top, which 
is then closed by the stopper K. 

About 0.5 gram of the dried sodium bicar- 
bonate, or I gram of the baking powder, is in- 
troduced into the flask .4 through the neck a 
from a weighing-tube or otherwise, so that its 
exact weight is kno\^-n. The stem B' is then 
inserted, and ihe funnel-top A' is nearly filled 
with the hydrochloric acid, the tube e being p.^^ ;o.-Geissler's CO, Ap- 

closed. paratus or .\lkaliineter. 

The entire apparatus is then weighed, after which the stem is turned 
to bring the protuberance e nearly opposite the tube E, uncovering it 
enough to allow the acid to pass slowly down the tube into the flask and 
upon the powder in the bottom of the flask. The carbon dioxide evolved 
passes through the opening / into the hollow stem B', thence up through 
he tube D, and down and up (as indicated by the arrows) through the sul- 
phuric acid, which absorbs the moisture. Finally the gas passes out 
through the tube K. 

After the evolution of the gas has continued for two or three minutes, 
gentle heat is applied '.o the flask from a gas flame, and the solution is 




338 



FOOD INSPECTION ^ND ANALYSIS. 



brought to boiling, which is continued for a few minutes, during the latter 
portion of which the stopper h is removed, and the tubulure connected 
by rubber tubing with a system of two U tubes, one containing soda 
lime, and the other calcium chloride. The tube k is then connected with 
the aspirator^ and a current of dried air is passed through the apparatus at 
the rate of about two bubbles per second, long enough to displace all 
the carbon dioxide. The rubber tubes are then disconnected, the stopper 
K is replaced, and the apparatus cooled to room temperature and weighed. 

The available carbon dioxide in baking powder is determined in the 
same manner as above, by simply substituting freshly boiled, distilled 
water for the hydrochloric acid in the funnel-top A'. 

The Knorr Apparatus [Modified). — ^The apparatus (Fig. 71) consists 
of (i) a flask, into which is introduced an accurately weighed amount of 




Fig. 7.1. — Modified Knorr Apparatus for Determining Carbon Dioxide. 

the dry samp^.e (0.5 to i gram of sodium bicarbonate or i to 2 grams of 
baking powder); (2) a funnel, the tube of which, provided with a stop- 
cock enters the stopper of the flask; (3) a soda lime tube, entering a 
stopper at the top of the funnel; (4) a Liebig condenser, connecting with 
a tube passing through the stopper of the flask; (5) a Geissler bulb, filled 
with the sulphuric acid; (6) a potash absorption-bulb, and (7) a calcium 



CEREALS, LEGUMES, yEGETABLES, AND FRUITS. 339 

chloride tube, which may if desired be replaced by a second sulphuric 
acid bulb. The potash absorption apparatus is accurately weighed 
before being connected up, and the funnel is nearly filled with the hy- 
drochloric acid reagent, after which the soda hme tube is attached. The 
calcium chloride tube is connected by a rubber tube with the aspirator, 
and a current of cold water is allowed to run through the outer Liebig 
condenser-tube. 

The stop-cock in the funnel-tube is first opened to allow the acid 
to slowly run into the flask, the flow being regulated to insure slow evolu- 
tion of the gas. 

The aspirator is then turned on so that about two bubbles of air per 
second pass through the apparatus, and gentle heat is apphed to the 
flask by the gas flame, the solution within being brought to boiling, and 
the boiling continued for several minutes after the vapor has begun to 
gather in the condenser. 

Prolgnged boiling of the solution should be avoided, and in a series of 
tests the time of boihng should be precisely the same in all cases. 

After removing the flame, the flask is allowed to cool, the aspiration 
being continued. The absorption-tube is then removed and weighed 
at room temperature, the increase in weight being due to the carbon 
dioxide. 

The Available Carbonic Acid in Baking Powder is determined in the 
same manner as the total carbon dioxide, except that recently boiled, 
distilled water is substituted for the hydrochloric acid. 

Detection of Tartaric Acid.* — It is often desirable to test a " com- 
pound " cream of tartar, or a " cream of tartar substitute," or an 
adulterated sample made up largely of foreign ingredients, to see if any 
tartaric acid, free or combined, be present. The following test is 
applicable in presence of phosphates: 

If the substance to be tested is found to be free from starch, mix a 
little of the dry powder in a test-tube with a bit of dry resorcin, add a 
few drops of concentrated sulphuric acid, and heat slowly. A rose-red 
color indicates tartaric acid or a tartrate, the color being discharged on 
dilution with water. 

In case of baking powder, or a cream of tartar substitute containing 
starch, shake repeatedly from 3 to 5 grams of the sample with about 

* Wolff, Rev. Chim. Analyt. et appr. 4 (1899), p. 2631. | 



340 FOOD INSPECTION JND /IN A LYSIS. 

250 cc. of cold water in a large flask, allowing the insoluble portion to 

subside. 

Decant the solution through a filter, and evaporate the filtrate to dryness, 

after which test the dried residue or a portion thereof with resorcin and 

sulphuric acid as above described. 

Determination of Total Tartaric Acid. — Modified Heidenhain 
Method.*' — ^Applicable only in the absence of phosphates and salts of 
aluminum and calcium. 

Into a shallow porcelain dish, 6 inches in diameter, weigh out 2 grams 
of the material and sufficient potassium carbonate to combine with all 
tartaric acid not in the form of potassium bitartrate. Mix thoroughly 
with 1 5 cc. of cold water, and add 5 cc. of 99% acetic acid. Stir for half 
a minute with a glass rod bent near the end. Add 100 cc. of 95% alcohol, 
stir violently for five minutes, and allow to settle at least thirty minutes. 
Filter on a Gooch crucible with a thin layer of paper pulp, and wash 
with 95% alcohol until 2 cc. of the filtrate do not change the color of 
litmus tincture diluted with water. Place the precipitate in a small cas- 
serole, dissolve in 50 cc. of hot water, and add standard fifth-normal potas- 
sium hydroxide solution, leaving it still strongly acid. Boil for one minute. 
Finish the titration, using phenolphthalein as indicator, and correct the 
reading by adding 0.2 cc. One cc. of fifth-normal potassium hydroxide 
solution is equivalent to 0.026406 gram tartaric anhydride (C^H^O^), 
0.03001 gram tartaric acid (HjC^H^Og), and 0.03763 gram potassium 
bitartrate (KHC,H,Oe). 

The standard of the potassium hydroxide solution should be fixed by 
pure dry potassium bitartrate. 

The accuracy of this method is indicated by the agreement of the 
percentages of potassium bitartrate in cream of tartar powders containing 
no free tartaric acid, obtained by calculation from the tartaric acid, with 
those obtained by calculation from the potassium oxide. 

In presence of phosphates or of aluminum and calcium salts, the only 
satisfactory method of arriving at the amount of tartaric acid present is 
by difference, having determined or calculated the other ingredients. 

Kenrick's Polariscopic Methods. — Method 1. {Applicable to Cream 
of Tartar). — The method is based on the fact that in the presence of 
excess of ammonia, the rotation of the solution is proportional to the 



* Provisional methods of the A. O. A. C, Bur. of Chem., Bui. 65, p. 104; Bui. 107 (rev.), 
P- 175- 



CEREALS, LEGUMES, l^EGETABLES, AND FRUITS. 34 1 

concentration of the tartaric acid, and is independent of the other bases 
and acids present. 

(a) The Substance is Completely Soluble in Dilute Ammonia. — A 
weighed quantity of the material containing not more than i gram tartaric 
acid is placed in a 25 cc. measuring flask, moistened with 3 or 4 cc. of 
water, and concentrated ammonia (sp. gr. 0.880) added in quantity suf- 
ficient to neutralize all acids that may be present, and leave about i cc. 
in excess. The actual amount of the excess is not of importance, but a 
greater quantity than i cc. of free ammonia should be avoided. The 
solution is then made up to 25 cc. with water, filtered, if necessar}', 
through a dn,' filter, and measured in a 20 cm. tube in the polarimeter. 

The amount of tartaric acid (C4Hg06) in grams {y) in the material 
taken is given by the formula: 

y = 0.005 1 9.x:, 

where .v is the rotation in minutes. 

{b) The Substance is not Completely Soluble in Dilute Ammonia. — In 
this case calcium tartrate is probably present, and may be determined 
as follows: Treat i gram of the substance (or an amount containing 
not more than i gram of tartaric acid) in a small beaker with 15 cc. of 
water, and 10 drops of concentrated hydrochloric acid. Heat gently 
tiU both the potassium and calcium tartrates have passed into solution, 
and then, while still hot, add 2 cc. of concentrated ammonia (or enough 
to produce an ammoniacal smelling hquid),and about o.i gram of sodium 
phosphate dissolved in a little water. Transfer to a 25-cc. measuring 
flask, cool, make up to the mark with water, filter through a dry filter, 
and polarize the filtrate in a 20-cm. tube. The tartaric acid is calculated 
from the formula given under (a). 

The precipitation of the calcium by means of sodium phosphate is 
not absolutely necessary, but when this is not done, in cases where the 
proportion of calcium in the sample is high, there is a great tendency 
for the calcium tartrate to crystallize out from the ammoniacal solution 
before the reading is made. 

The tartaric acid present as bitartrate of potash may be determined 
by proceeding as in (a), the calcium tartrate being practically insoluble 
in cold ammonia solution. 

The tartaric acid present as calcium tartrate is given, with sufficient 
accuracy for most purposes, by the difference between the results of (a) 
and [b). If more accurate results are required, the residue insoluble in 



342 



FOOD INSPECTION AND ANALYSIS. 



ammonia in (a) may be dissolved in a little hydrochloric acid and treated 
as above with sodium phosphate and ammonia. 

Method 2. {Applicable to Baking Poivder and Cream of Tartar mixed 
with Substitutes). — Direct readings of rotation in ammoniacal solution 
are inadmissible in analyses of the substances of this class, on account 
of the influence of iron and aluminum on the rotation of tartaric acid, 
and on account of the small but unknown rotation of the trace of inverted 
starch. 

Accurate determinations, however, may be made in the presence of 
excess of ammonium molybdatc in neutral solution. The latter substance 
has the property of greatly increasing the rotation of tartaric acid, so 
that by its use the small rotation of the inverted starch is made insignifi- 
cant. It is to be noted, however, that this increased rotation is very 
sensitive to the presence of alkali and acid, and is, moreover, modified 
by phosphates. It is therefore necessary, in the first place, to remove 
the phosphoric acid, and, secondly, to bring the solution to a definite 
state of neutrality. Both these results are attained by the following 
procedure, the details of which must be carefully adhered to: 

(a) Reagents. — The following solutions must be prepared, but need 
not be made up very accurately: 

Molybdate solution: 44 grams ammonium heptamolybdate in 250 cc. 
Citric acid solution: 50 grams citric acid in 500 cc. 
Magnesium sulphate solution: 60 grams MgS04 . 7H2O in 500 cc. 
Ammonia solution: 80 cc. concentrated ammonia (sp. gr. 0.880) in 
500 cc. 

Hydrochloric acid: 60 cc, concentrated hydrochloric acid in 500 cc. 
Methyl orange solution: 

(b) Process. — An amount of material containing not more than 0.2 
gram tatraric acid, not more than 0.3 gram alum, and not more than 
0.3 gram calcium superphosphate, is accurately weighed, and placed in 
a dry fiask. To this, 5 cc. of citric acid and 10 cc. of molybdate solution 
are added, and allowed to react with the substance for 10 or 15 minutes 
(with an occasional shake). Next, 5 cc. of magnesium sulphate solution 
are added, and 15 cc. of ammonia solution stirred in. After a few 
minutes (not more than one hour), the solution is filtered through a dry 
filter, a slight turbidity of the filtrate being disregarded. To 20 cc. of 
the filtrate are then added a few drops of methyl orange and hydrochloric 
acid, from a burette, till the pink color apjjears (2 or 3 drops too much 
or too little are of no consequence). Finally, 10 cc. more of the molybdate 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



543 



solution are added to the pink solution, which now becomes colorless 
or pale yellowy and water is added to make up the volume to 50 cc. 
This solution, after filtering if necessary, is polarized in a 20-cm. tube. 
The amount of tartaric acid in grams {y) in the weight of substance 
originally taken is given by the following formula, in which x is the 
rotation in minutes: 

;)' — o.ooio86x + o.ooi6oi\/x 
But if the rotation is not less than 40', the simpler formula j 

;y = 0,007 5 -f 0.00 1 1 68:v, 
may be employed. 

The following table gives the tartaric acid in grams for every 10 mmutes 
rotation: 



Rotation in Minutes. 


Grams 

Tartaric 

Acid. 


Rotation in Minutes. 


Grams 

Tartaric 

Acid. 


10 


0.016 

0.029 

0.0415 

0.0535 

0.0657 

0.0776 

0.0895 

0.1013 


90 

100 


0.1130 
. 1 246 

0.1365 
0.1479 

0.1595 
0.1710 
0.1825 


20 

30 

40 

50 

60 

70 

80 


1 10 


I 20 


130 

140 

150 



Determination of Starch. — McGilVs Method* {Modified). — Digest 
I gram of the sample with 150 cc. of a cold 3% .solution of hydrochloric 
acid during twenty-four hours, with occasional shaking. Filter through 
a tared Gooch crucible, wash first with water until neutral, then once 
with alcohol, and finally with ether. Dry at 110° C. for four hours, cool, 
and weigh. Burn off the starch, and again weigh. The difference in 
the two weights indicates the weight of the starch. The purity of the 
starch is insured by examination with the microscope. 

Acid Conversion Method. f — If the sample contains lime, mix 5 grams 
in a 500-cc. flask with 200 cc. of 3% hydrochloric acid, and let the mixture 
stand an hour with frequent shaking. Filter through a wetted ii-cm. 

* Canada Inland Rev. Bui. 68, p. ^t,. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 105; Bui. 107 rev., p. 176. 



344 FOOD INSPECTION ^ND ^N^ LYSIS. 

filter, wash with water, and transfer the starch by a wash-bottle from the 
filter-paper back into the original flask, using 200 cc. of water. 

If the sample be free from lime, weigh 5 grams directly into the 500-cc. 
flask with 200 cc. of water. In either case add 20 cc. of hydrochloric 
acid (specific gravity 1.125) and heat the flask in boihng water for 2^ 
hours, the flask being provided with a reflux condenser. Determine the 
dextrose, and from this the starch in the regular manner. 

Detection of Aluminum Salts.* — (a) In Baking Powder. — Appli- 
cable in presence of phosphates. Burn to an ash about 2 grams of the 
sample in a platinum dish. Extract with boiling water and filter. Add 
to the filtrate sufficient ammonium chloride solution to produce a distinct 
odor of ammonia. A flocculent precipitate indicates aluminum. 

In igniting, as above directed, sodium aluminate results from the 
more or less complete fusion. The reaction which occurs may be repre- 
sented as follows: 

Na2Al20,+ 2NH,C1 + 4H20 = Al2(OH)6+ 2NH,OH+ 2NaCl. 

Sodiurr. Ammonium Aluminum Ammonia Salt 

aluminate . chloride hydroxide 

If any phosphate of lime be present, it will be insoluble in the solution 
of the ash. If phosphate of sodium or potassium be present, it will go 
into solution, but wiU only precipitate out when an aluminum salt is also 
present on the addition of the ammonium chloride reagent. 

(b) In Cream of Tartar. — Mix about i gram of the sample with an 
equal quantity of sodium carbonate, burn to an ash, and proceed as in 
the case of baking powder (a). 

Determination of Alumina. — The above qualitative method with am- 
monium chloride may be made quantitative in presence of phosphates 
as follows: After carrying out the qualitative method as above directed, 
filter off the final precipitate, dissolve it in nitric acid, and test it for phos- 
phate with ammonium molybdate. If phosphates are found absent, 
proceed as before with a weighed amount of the sample and wash, ignite, 
and weigh the residue as AI2O3. 

If phosphate is found present in the ammonium chloride precipitate, 
proceed as before, igniting and weighing the total residue. Then deter- 
mine the P2O5 in the latter and subtract from the total. The difference 
will be the AI2O3. 



* Leach, 31st An. Rep. Mass. State Board of Health, 1899, p. 638. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 345 

Determination of Lime. — 5 grams of the sample are treated in a 
500-cc. graduated flask with 50 cc. of water and 25 cc. of concentrated 
hydrochloric acid. Add water to the mark, shake, and allow the starch 
to settle. Decant through a dry filter, and to 50 cc. of the filtrate 
add ammonia nearly to neutralization, an excess of ammonium 
acetate solution, and 4 cc. of 80% acetic acid, and heat at 50° C. 
Filter if necessary, and precipitate the lime with an excess of 
ammonium oxalate. Filter, wash, and ignite over a blast-lamp. Weigh 
as CaO. 

Determination of Potash and Soda.* — Weigh out 5 grams into a 
platinum dish, and incinerate in a muftle at a low heat. The charred 
mass is well rubbed up in a mortar, then boiled fifteen minutes with 
about 200 cc. of water, to which has been added a little hydrochloric 
acid. The whole is transferred to a 500-cc. flask, and, after cooling, 
made up to the mark and filtered. Of the filtered hquid 100 cc, 
representing i gram of the sample, are measured out, heated to boiling, 
and a slight excess of barium chloride solution added; then without 
filtering barium hydroxide is added in slight excess, the precipitate 
filtered off, and washed. To the filtrate is added a little ammonium 
hydroxide, and ammonium carbonate solution until the barium is pre- 
cipitated. This precipitate is filtered and washed, the filtrate evapo- 
rated to dryness, and carefully ignited below redness until all volatile 
matter is driven off. The residue is dissolved in a few cc. of water, and 
a few drops of ammonium carbonate solution added. The precipitate, 
if any, is removed by filtering and washing, and the filtrate evaporated 
in a small tared platinum dish, ignited below redness, and weighed. 
This gives the weight of the mixed chlorides. The residue is taken up 
with hot water, from 5 to 10 cc. of a io9c solution of platinic chloride 
added, and the whole evaporated to a sirupy consistency on the water- 
bath; it is then treated with 80*;"^ alcohol, the precipitate washed with 
80% alcohol by decantation, transferred to a Gooch crucible, dried at 
100° C, and weighed. The weight of the precipitate, multiphed by 
0.IQ308, gives the weight of K2O, and by 0.3056 the equivalent amount 
of KCl. The weight of KCl found is subtracted from the weight of 
the mixed chloride, the remainder being XaCl, which, multiplied by 
0.5300 gives the weight of Xa20 in the sample. 

* U. S. Dept. of .A.gric., Div. of Chem., Bui. 13, part 5, p. 593. 



340 FOOD INSPECTION /IND ANALYSIS. 

Determination of Phosphoric Acid. — Method oj the A. O. A. C* — 
Mix 5 grams of the material with lo cc. of magnesium nitrate solution, f 
dry, ignite, and dissolve in hydrochloric acid. Take an aliquot part of 
the solution prepared above, corresponding to 0.25 gram, 0.50 gram, or 
I gram, neutralize with ammonia, and clear with a few drops of nitric 
acid. In case hydrochloric or sulphuric acid has been used as solvent, 
add about 15 grams of dry ammonium nitrate, or a solution containing that 
amount. To the hot solution add 50 cc. of molybdic solution^ for every 
decigram of P2O5 that is present. Digest at about 65° for an hour, filter, 
and wash with cold water, or preferably ammonium nitrate solution. § 
Test the filtrate for phosphoric acid by renewed digestion and addition 
of more molybdic solution. Dissolve the precipitate on the filter with 
ammonia and hot water and wash into a beaker to a bulk of not more 
than 100 cc. Nearly neutralize with hydrochloric acid, cool, and add 
magnesia mixture from a burette; add slowly (about i drop per second), 
stirring vigorously. After fifteen minutes add 30 cc. of ammonia solution 
of density 0.96. Let stand for some time; two hours is usually enough. 
Filter, wash with 2.5% NH3 until practically free from chlorides, ignite 
to whiteness or to a grayish while, and weigh. 

Determination of Sulphuric Acid. — Provisional Method A. O. A. C.\\— 
Boil 5 grams of the powder gently for one and one-half hours with a mix- 
ture of 300 cc. of w^ater and 15 cc. of concentrated hydrochloric acid. 
Dilute to 500 cc, draw off an aliquot portion of 100 cc, dilute considerably, 
precipitate with barium chloride, filter through a Gooch crucible, ignite, 
and wTigh. Direct solution of the material without burning the organic 
matter was proposed by Crampton.l" The dextrose, formed by the action 
of the acid on the starch of baking-powders, does not interfere with the 
accuracy of the process. 

Determination of Ammonia (present in the form of ammonia alum 
or ammonium carbonate). Mix 5 grams of the sample with 200 cc. of 
water, and add an excess of sodium hydroxide. Distill into standard 
acid, and determine the ammonia by titration. 

* U. S. Dept. of Agric, Div. of Chem., Bui. 46, p. 12; Bui. 107 (rev.), p. 4. 

t Prepared as follows: Dissolve 80 grams calcined magnesia in nitric acid, avoiding an 
excess of acid, then add a little calcined magnesia in excess, boil, filter from the excess of 
magnesia, ferric oxide, etc., and dilute with water to 500 cc. 

X Reagent No. 53. 

§ Prepared by dissolving 100 grams of ammonium nitrate. Reagent No. 54, in i liter of 
water. 

U U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 107; Bui. 107 (rev.), p. 178. 

^ U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 5, p. 596. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



347 



SEMOLINA, MACARONI, AND EDIBLE PASTES. 

Semolina is the coarse meal ground from certain varieties of hard 
or " durum " wheats, grown originally in Italy, Sicily, and Russia, but 
at present in France and certain parts of the United States and Canada. 
This hard wheat is high in gluten, and especially adapted for the prepara- 
tion of macaroni and the various pastes. A peculiar process is employed 
in preparing the wheat, whereby the husk is removed by wetting, heating, 
grinding, and sifting, the resulting meal or semolina, being in the form 
of small, round, glazed granules. 

Italian Pastes. — Semolina furnishes the basis of the Italian edible 
pastes, being mixed with warm water, kneaded, and molded into various 
forms, either by pressure through holes in an iron plate, or otherwise, 
and finally dried. In parts of Italy juices of carrots, onions, and other 
vegetables are said to be mingled with the paste, but for local consumption 
only. Saffron is sometimes added to pastes for the purpose, so it is 
claimed, of imparting a spicy flavor, although the quantity used is often 
so small as to be apparent only to the eye, thus indicating that the real 
object of its addition is to impart a color in imitation of an egg paste. 

Macaroni is the larger of the slender-tube or pipe-shaped products; 
■vermicelli is the worm-shaped variety, produced when the holes in the 
plate are very small; spaghetti is the term applied to the cord -like paste 
intermediate in size between the others. A variety of Italian pastes or 
pates is made by rolling the kneaded semolina into thin sheets, and cutting 
out in shapes of animals, letters of the alphabet, etc. 

The composition of some of these products is as follows: 



No. of I 
Samples. 



Water. 



Protein. 



Fat. 



Total 
Carbohy- 
drates. 



Crude 
Fiber. 



Ash. 



Fuel 
Value 

per 
Pound. 
Cal's. 



Semolina * ' 

Macaroni f | n 

Noodles t ■ 2 

Spaghetti f 3 

Vermicelli f 15 

*Balland. 



10.50 
10.3 
10.7 
10.6 
II. o 



11.96 

13-4 
II. 7 



0.60 
0.9 

I.O 

0.4 

2.0 



75-79 

74-1 

75-6 

76.3 

72.0 



0.50 



0.4 
0.4 



0.65 

1-3 
1.0 
0.6 
4-1 



1665 
1665 
1660 
1625 



t Atwater and Bryant. 



Noodles are a strap-shaped form of paste made in German house- 
holds as well as in factories. True, or egg-noodles, contain a certain 
percentage of eggs, while water-noodles are practically the same in com- 
position as Italian pastes. The difference in composition between water- 



348 



FOOD INSPECTION /1ND ANALYSIS. 



noodles and noodles made with different numbers of eggs or egg yolks 
per German pound of flour, is shown by the analyses of Juckenack and 
Pasternack* given in the following table :t 





Composition of the Dry Matter. 





Composition of the Dry Matter. 


^^ 






j 














S c 


Ash. 


Total 
Phos- 
phoric 

Acid. 


Lecithin 
Phos- Ether 
phoric Extract 
Acid. 


Protein 
NX6i 


u 3 
<a 
X^P-, 


Ash. 


Total 
Phos.- 
phoric 
Acid. 


Lecithin 
Phos- 
phoric 
Acid. 


Ether 
Extract 


Protein 
NX6i 


^ 










gS. 












o 


% 
0.460 


% 
0.2300 


% 
0.0225 


% 
0.66 


% 
12.00 





% 
0.460 


% 
0.230c 


% 
0.0225 


% 

0.66 


% 
12.03 


I 

2 


0.565 
0.664 


0.2716 
0.3110 


0.0513 
0.0786 


1.56 
2.42 


12.99 
13-92 


I 

2 


0.488 
0.516 


0.2720 
0.3127 


0.0518 
0.0801 


1-57 
2.47 


12.37 
12.73 


3 
* 


0.758 
* 


0.3482 


0.1044 


3-24 

* 


14.81 
* 


3 
* 


0.542 
* 


0.3520 
* 


0.1075 


3-33 

* 


13.07 
* 


12 


1.426 


0.6123 


0.2875 7-94 


21.09 


12 


0.745 


0-6533 


0.3171 


8.64 


i5-|7i 



From these results it appears that the percentages of ash, total phos- 
phoric acid, and protein are appreciably increased by the addition of 
each egg or egg yolk, while the percentages of lecithin-phosphoric acid 
and ether extract are more than doubled by the addition of the first egg, 
and are increased in corresponding proportion by the addition of two or 
more eggs. 

The German Association of Food Chemists require that commercial 
egg-noodles contain at least 0.045% ^f lecithin-phosphoric acid, and 
2.00% of ether extract, corresponding to the minimum in noodles with 
two eggs per half kilogram of flour, 

Spaeth I considers that if the ether extract of noodles has an iodine 
number over 98, it is safe to assume that they contain no eggs or only 
traces. 

In interpreting the results of analysis it should be remembered that 
fat may have been introduced in some form other than in eggs, and that 
the lecithin-phosphoric acid diminishes somewhat on long standing. 
Allowance should also be made for the variation in composition of the 
eggs and flour. 

Of 22 brands of American noodles examined by Winton and Bailey§ 
only 5 appeared to be made with eggs; the lecithin-phosphoric acid in 

* Zeits. Unters. Nahr. Genuss., 3, 1900, p. 13; 8, 1904, p. 94. 

t The German pound is approximately 468 grams; the avoirdupois pound is 454 grams. 

i Forsch. uber Lebensm., 3, 1896, p. 49. 

§ Jour. Am. Chem. Soc. 1905, 37, p. 137; Rep. Conn. Exp. Sta., 1904, p. 138. 



CEREALS, LEGUMES, J/EGETABLES, AND FRUITS. 349 

these ranged from 0.036 to 0.058, and the ether extract from T.83 to 2.33 
per cent, while in the other samples the lecithin-phosphoric ranged from 
0.015 to 0.032 and the ether extract from 0.28 to 2.50 per cent. 

Adulteration of Pastes. — Rice, corn, and potato flours have been 
used in the preparation of the cheaper varieties of semolina, but rarely 
in this country. A more common form of adulteration is the substitution 
of water-noodles for egg-noodles, artificial colors being used to carry 
out the deception. Substitutions of this kind are detected by determina- 
tions of lecithin-phosphoric acid and ether extract, supplemented by tests 
for artilicial colors. 

ANALYSIS OF PASTES. 

Determination of Lecithin-phosphoric Acid. — Jiickenack's Method* 
— Extract 30 gram^ of the finely ground material for 10 hours with abso- 
lute alcohol in a Soxhlet extractor at a temperature, inside the extractor, 
not below 55°-6o° C. The extraction flask should be provided with a 
small quantity of pumice stone to prevent bumping during the boiling, and 
the extractor enclosed by asbestos paper, if the desired temperature is not 
readily maintained. After the extraction is completed, add 5 cc. of ako- 
hohc solution of potash (prepared by dissolving 40 grams of phosphorus- 
free caustic potash in 1000 cc. alcohol), and distil off all the alcohol. 
Transfer the residue to a platinum dish by means of hot water, evaporate 
to drvness on a water bath, and char over asbestos. Treat the charred 
mass with dilute nitric acid, filter, and wash with water. Return the 
residue with the paper to the platinum dish, and burn to a white ash. 
Treat again with nitric acid, filter and wash, uniting the filtrates. 
Determine phosphoric acid by the usual method. 

Detection of Artificial Colors in Pastes. — The following colors 
have been used in noodles and other pastes: turmeric, saffron, annatto, 
naphthol yellow (Martius yellow), naphthol yellow S, picric acid, aurantia, 
Victoria yellow, tartrazine, metanil yellow, azo yellow, gold yellow, and 
quinoline yellow. Of these naphthol yellow, picric acid, metanil yellow, 
and Mctoria yellow are injurious to health, and their use is illegal in 
European countries as well as in the United States. Fortunately, they 
are rarely found in the products now on the market. 

The detection of artificial colors is complicated by the presence of the 
natural coloring matter of the flour and the lutein of eggs. These are 

* Zeits. Unters. Nahr. Genuss., 3, 1900, p. 13. 



$^0 FOOD INSPECTION AND ANALYSIS. 

conveniently extracted by ether, which does not remove the artificial 
colors, although most of them unmixed dissolve freely in this solvent. 

Juckenack's Method* — Thoroughly shake two portions of the finely 
ground material, each of about lo grams, in test tubes with 15 cc. of 
ether and 15 cc. of 70% alcohol respectively, and allow to stand 12 hours. 

(a) If the ether remains uncolored or only slightly tinted and the 
material below it remains yellow, while the alcohol is distinctly colored 
and the material is decolorized, a foreign dye is indicated. 

(b) If both ether and alcohol are colored, either (i) lutein (egg color) 
alone, or (2) "this with a foreign dye is present. 

1. Treat a portion of the ether solution with dilute nitrous acid, 
according to Weyl. If the ether is not completely decolorized, a foreign 
dye is present. 

2. If the deposit of material below the alcohol is decolorized, while 
that below the ether is colored, tests should be made for foreign dyes as 
follows: Shake the portion previously treated with ether with three or 
more fresh portions of the same solvent, until no more color is extracted, 
and then shake the residue with 70% alcohol and allow to stand 12 hours. 
After filtering, concentrate the solution slightly, acidify with hydrochloric 
acid, boil with sensitized wool, and identify the color in the usual manner 
(page 799). 

. SchlegeVs Method.'\ — Extract 100 grams of the finely powdered material 
with ether in a continuous extraction apparatus, and shake the residue 
at frequent intervals for half a day with a mixture of 140 cc. of alcohol, 
5 cc. of ammonia, and 105 cc. water. Filter, evaporate to remove alcohol 
and ammonia, acidify slightly with hydrochloric acid, and again filter. 
Boil the filtrate with sensitized wool, and identify the color on the dyed 
fiber by the usual tests (page 799). 

Fresenius Method.X — Extract 20 to 40 grams of the powdered material 
with ether in a continuous extraction apparatus. Dry the residue to 
remove ether, shake for 15 minutes with 120 cc. of 60% acetone, and 
allow to stand 12 to 24 hours. Filter, evaporate until the acetone is 
removed, and divide into two portions, a larger and a smaller. To the 
larger portion add sufficient acetic acid to dissolve flocks, and boil with 
sensitized wool. Remove natural coloring matter from the wool by 
boiling in dilute acetic acid. If after this treatment the wool is dyed 

* Zeits. Unters. Nahr. Genuss., 3, 1900, p. i. 

t Untersuchungsanstalt, Niirnberg, Ber. 1906, p. 24. 

% Zeits. Unters. Nahr. Genuss., 13, 1907, p. 132. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 351 

the presence of a foreign color is indicated, which may be identified by 
the usual tests. 

To the smaller portion of the aqueous solution, obtained after removal 
of the acetone as above described, add an equal volume of alcohol, heat 
to dissolve flocks, divide into four portions, and apply special tests to 
three of these, reserving the fourth for comparison. The natural color 
of the flour is decolorized by hydrochloric acid, intensified by ammonia, 
but not affected by stannous chloride, even on heating. Saffron reacts 
in a similar manner, but is only slightly bleached by the acid, and is not 
affected by the other two reagents. 

Piutti and Benfivoglio Method* — This method is especially designed 
to detect the four colors forbidden by Italian law, and to distinguish 
these from naphthol yellow S. 

Boil 50 grams of the paste in 500 cc. of water, made alkaline with 2 
cc. of concentrated ammonia water, add 60 to 70 cc. of alcohol, and 
continue the boiling 40 minutes. After filtering, acidify the liquid with 
2 to 3 cc. of dilute hydrochloric acid and boil with 5 to 6 strands of sensi- 
tized wool, each strand weighing about 0.5 gram. Wash the wool, 
dissolve the color in dilute ammonia, and repeat the dyeing. After 
dissolving a second time in ammonia, evaporate the solution of the dye 
to dryness, avoiding as far as possible the formation of a skin, and take 
up the residue in water. If a skin has formed, filter and test the insoluble 
matter for metanil yellow with dilute hydrochloric acid, and for picric 
acid with ammonium sulphide. 

To I cc. of the filtrate add stannous chloride solution and a little 
sodium hydroxide, or preferably sodium ethylate. If no red color forms, 
nitro-colors are absent; if, also, in another portion dilute hydrochloric 
acid produces no violet color, thus showing the absence of metanil yeUow, 
no further test is necessar}'. In the presence of these colors, acidify the 
remainder of the solution with acetic acid, shake violently with carbon 
tetrachloride, and identify the color according to the following scheme: 

-4. Color dissohes in carbon tetrachloride to colorless solution. 
Extract with very dilute ammonia, concentrate and divide into two parts. 

1. Acidify with hydrochloric acid, and add i to 2 drops of stannous 
chloride and ammonia in excess. A rose colored solution and precipi- 
tate form Naphthol yellow. 

2. Acidify slightly with hydrochloric acid, add a little zinc dust and 
stir. Solution becomes rose-violet Victoria yellow. 

* Gaz. chim. Ital. 36, II, 1906, p. 385. 



352 



FOOD INSPECTION AND ANALYSIS. 



B. Color is insoluble in carbon tetrachloride. Evaporate to dryness 
on water-bath, take up in water and divide into three parts. 

1. Hydrochloric acid produces a violet coloration Metanil yellow. 

2. Ammonium sulphide produces a red brown coloration. 

Picric acid. 

3. Stir on a water-bath with zinc dust and ammonia, filter, treat with 
zinc dust and hydrochloric acid and again filter, (a) Potassium hydroxide 
produces a yellow coloration, and {h) ferric chloride an orange coloration. 

Naphthol yellow S. 

Schmitz-Dumont Test for Tropeolins* — ^loisten a small portion of 
the material with a few drops of dilute hydrochloric acid. The formation 
of a reddish or bluish color shows the presence of an azo color or some 
other coal-tar color. 

Test for Turmeric. — Extract the color from the ground material by 
alcohol and identify by the boric acid test (page 789). 

Shredded Wheat is a whole-wheat preparation, put out in the form 
of light biscuits buik up of fine porous threads, not unlike those of vermi- 
celli. The wheat, softened by boiling, is shredded by passing through 
a peculiar machine, after which the biscuits are made by lightly putting 
together the threads and by final baking. The comparative composition 
of shredded wheat and of typical whole wheat is thus shown by Wiley :t 



Constituents. 



Shredded 


Typical 


Biscuit. 


Wheat. 


Per Cent. 


Per Cent. 


10-57 


10.60 


12.06 


12.25 


1-03 


1-75 


2.65 


1-75 


2.58 


2.40 


71. II 


71-25 



Moisture 

Proteins 

Ether extract 

Ash 

Crude fiber 

Carbohydrates other than fiber. 



PREPARED CEREAL BREAKFAST FOODS. 

The large number and variety of these preparations now on the market 
testify to the fact that the breakfast cereal forms a most important, as well 
as considerable, portion of our food supply. These foods are generally 
prepared from wheat, oats, and corn, and are, as a rule, remarkably pure 
and free from adulteration, though the food value of different varieties 



* Zeits. offent. Chem., 8, 1902, p. 424. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 13, p. 1337. 



CEREALS, LEGUMES. l^EGET/IBLES, AND FRUITS, 353 

is often grossly misstated by their manufacturers. Formerly the break- 
fast food consisted entirely of the coarsely ground, generally decorticated, 
raw cereal grain, and required a long period of cooking to prepare it for 
use. At present many of the oat products, and to some extent also those 
of com, rice, and wheat, are subjected to a more or less preliminan- cook- 
ing and dr}-ing, whereby they are capable of being prepared for use in 
a much shorter time, and their keeping qualities are enhanced. The 
so-called rolled oats are prepared by softening the grains through steam- 
ing, after which they are crushed between rollers and afterwards dried. 
The steaming process is a t}'pical one for various other cereals, though 
in some cases the heating consists in baking or kiln drying. 

The effect of the preliminar}- cooking on the finished product varies 
somewhat according to whether dxy or moist heat has been appUed, and 
is chiefly noticeable in the altered character of the carbohydrates. In 
all cases the starch is rendered more soluble, whether by the conversion of 
a portion into dextrin and dextrose, or by a simple breaking down 
of the starch grains, as in the case of bread in baking. 

In spite of the seemingly endless variet}- of the package cereals, they 
divide themselves as a matter of fact into a ver/ few weU-defined classes, 
the members of which differ but little from each other except in name. 

First there are the raw cereal grains of the oat, wheat, and com, pre- 
pared by simple crushing to various degrees of fineness, after decorticating; 
next comes the classes of partially cooked preparations of each of these 
grains, appearing in various forms of ''flakes," "granules," "grits," 
etc., and again a class known as malted cereals, in which the moist, ground 
grain is mixed ■^^th malted barley, and, by controlling the temperature, 
a portion of the starch is converted to maltose and dextrin, after which 
the mixture is crushed between hot rollers and dried. 

In the preparation of most of the com breakfast products, such as 
samp and hominy, it is customar}' to remove the germ, which contains 
the oil and fat, lest the tendenc}' of the latter to become rancid should 
result in the deterioration of the food. In wheat foods the germ is less 
often removed, and rarely, if ever, in oat preparations. The amount 
of fat found in the prepared cereal food as compared "v^'ith that in the 
whole grain is of interest in this connection. 

Composition of Some of the Common Breakfast Cereals. — The follow- 
ing analvses will ser\-e to typif}' the various classes of these preparations 
as they appear on the market: 



^54 



FOOD INSPECTION y4ND y4NALYSIS. 



Wheat.* 

Wheatena 

Pettijohn's breakfast food.. 

Farina 

Cracked wheat 

Ralston's breakfast food 

Fould's wheat germ 

Oats.* 

Quaker 

Hornby's 

Buckeye 

Corn. 

Cereahne * - 

Velvet meal * 

Hecker's hominy t 

Nichols' snow-white sampt. - - 

MlSCELLANFOUS.t 

Brittle bits 

Force 

Grape-nuts 

Ralston's health barlev food. . 



6.65 

9-51 
10.94 

9-3° 

9.72 

10.13 

7.40 
7-63 

7-54 

9-55 
9.80 
II. I 
10.3 

6.9 

5-4 

4-2 

10.8 



Carbohydrates. 



1^ 



2.28 14.17 75.62 
i.4S'io 56 76.96 
1.56 10.90 75.91 
2.22 12.60 94.42 
i.9o'i5.iOj7i.75 
i-4613-30, 73-93 

6.08 17.20,66.65 

7-35'i7-82'65.47 
8.3016.89165.55 



1.24 
2.32 
0-3 
0-3 

0-5 
1-4 
I.I 
i.o 



9.90,78.75 

6-75180.53 
9.4 78.6 
8.2 80.=: 



14. 1 
II. 6 
12.6 
10.7 



76.0 
76.8 
78.4 
75-8 



3-9 
2.8 



4^ 



1.6 
1-3 
3-3 

7-1 



70.50 

72-15 
72.12 

69-63 
65.60 

69-35 

64-65 
62.74 
60.90 

70-93 
77-77 



1.22 
2.01 

0-59 
1.49 

1-55 
o.r 



1.40 
1-43 
1-35 

0.7 
0.96 
0.4 
0.4 



1.9 
0.6 



1.28 0.3631 
1.52 
0.69 
1 .46 

1-53 



1.67 

1-73 
1.72 

0.56 
0.60 
0.2 
0-3 

1-5 



231 
0-153 
333 
343 
0.326 

341 
0-443 
0.416 

.192 
.185 






4343 
4174 
4051 
4236 
4158 
4087 

4673 
4756 
4526 

4542 
3660 



* Analyses made by Slosson, WyominR Exp. Sta., Bui. 33- 

t Analyses made by Merrill and Mansfield, Maine Exp. Sta., Bill. 84. 

The methods of analysis employed for these preparations are the 
same as for ordinary cereals (p. 277), the sample being ground line 
enough to pass through a i-mm, sieve. 



PREPARED FOODS FOR INFANTS AND INVALIDS. 

In dealing with the composition and analysis of this class of proprie- 
tary foods more than ordinary care is necessary, in view of the fact that 
one or another of these preparations are frequently ])rescribed for the 
exclusive diet of those whose very life may depend on the character and 
suitability of the food to the case in hand. Many of these foods do, as 
a matter of fact, honestly fulfil the claims of their manufacturers, but 
others fall far .short of so doing, .so that it is hardly safe to u.se them unless 
•some intelligent idea of their composition can be gained. It is not, as 
a rule, within the province of the analyst to furnish an opinion regarding 
the adaptability of a certain food to the requirements of an infant or 
invalid, but rather to provide the necessary data whereon such an opinion 
may be intelligently based. 



CEREALS, LEGUMES, [VEGETABLES, AND FRUITS. 355 

A simple statement of moisture, fat, protein, carbohydrates (by dif- 
ference), and ash, which in the case of ordinary foods would often be 
sufficient, would be obviously inadequate in expressing the analysis of 
an infant food, since it is of much more vital importance than in other 
foods to know the solubihty of the food itself, and, to as great an extent 
as possible, the character of the carbohydrates. 

The chief ingredients of many of these preparations are wheat, or 
mixed cereals high in starch. ]Many of the foods are, according to the 
directions, to be used practically without cooking, but by simply mixing 
with milk or water, and, in some cases, bringing to the boiling-point. 
Hence the degree of conversion which the raw starch has undergone in 
the process of manufacture of the food should, if possible, be ascertained 
as a prime factor in judging of its character and adaptability to the needs 
of the young child and of the sick. Incidentally it should be said that 
few if any of the infant foods, even those whose high character has long 
been established by continued trial, conform very closely to the composi- 
tion of woman's milk, which was long accepted as the true standard on 
which to base their efficiency. Hence it is no easy task to pass judgment 
on a particular food from its chemical composition alone without trial, 
nor is it right to unqualffiedly condemn in all cases food high in insoluble 
carbohydrates, since there are undoubtedly many instances in which 
such foods are successfully used. 

Classification and Preparation of Infants' Foods. — These foods may 
for convenience be di\ided into two main classes, viz., farinaceous foods, 
or those which are prepared wholly or chiefly from one or more cereal 
grains, and lactated foods, or those in which cow's milk forms the basis, 
but which may contain in addition thereto various other substances, such 
as cereals, sugars, etc. 

The farinaceous foods, which are usually directed to be mixed with 
mills, before using, may be further subdivided into (a) those that consist 
chiefly of unconverted starch, {b) those whose starch has been nearly 
all hydrolyzed to soluble form in the process of manufacture, and (c) those 
which contam much unconverted starch, but ui addition thereto diastase 
or some other ferment, which, when the food is mixed with warm water 
or milk, is supposed to convert all the starch to soluble form. 

The unconverted starch foods are nearly all made up of baked dry 
flour, chiefly that of wheat, but sometimes a mixture of cereals (as oats, 
barley, and wheat) and sometimes oats or barley alone. The baking 



356 



FOOD INSPECTION /iND ANALYSIS. 



breaks down to some extent the starch grains, as in the case of bread 
or crackers, but does not actually convert much of it to sugar. 

The soluble farinaceous foods are usually prepared somewhat as 
follows: A mixture of ground wheat and barley malt (with sometimes a 
little wheat bran) is mixed with water to form a paste, and a little bicar- 
bonate of potash added. The mixture is heated at 65° C. for sufficient 
time to convert the starch, after which it is exhausted with warm water, 
the extract being strained, and the filtrate evaporated to dryness to form 
the food. The sugars of such foods consist largely of maltose mixed 
with dextrin. 

The farinaceous foods, which depend for the conversion of their starch 
on the method of cooking or heating before serving, are usually mixtures 
of wheat or other cereal flour with malt or pancreatic extract. 

The milk foods are variously prepared, either by the simple desicca- 
tion of cow's milk (usually previously skimmed) or, when whole milk 
is used, by mingling the desiccated milk with sugars or baked cereal flour. 
Sometimes desiccated milk is used in mixture with a dried extract of 
malted cereals. In fact all sorts of mixtures are found on the market, 
involving, however, in nearly all cases, one modification or another of 
the above general processes of preparation. 

- Composition. — Few complete analyses of these classes of foods have 
recently been made. Among the best are those of McGill,* from whose 
work the following figures have been selected, illustrating typical examples 
of foods on the market : 



Farinaceous foods: 

Imperial granum 

Ridge's food 

Mother's food 

Robinson's barley 

Mixed foods: 

Horlick's malted milk 

Lactated food 

Mellin's food 

Nestle's milk, food 

Reid & Carnrick's baby food 







i 




CJ 


<*-. m 




i3-S 




C3 


Si C3 


3 




p-5 





%< 


•3 


cS"' 


i< 


C 


12; 


s 


Sh 


a 


►-) 


5 


6.04 


0.72 




3-94 


9 


8.12 


0.48 


0.34 


4.67 




9-99 
9.41 


0.13 
0.41 






7 


0.65 


2.26 


9 

12 


2-55 
5-77 


1. 41 

0.48 






28.24 


4.27 


8 


4.72 


0.30 






9 


2.18 


4-45 


39-54 


4.30 


2 


5-69 


2.18 








■ 




3-94 
5.02 
8.83 
2.91 

63.87 
32.90 
82.0 

43-84 
38.21 



13- 

13-83 
8.60 
7.46 

14.00 
10.01 
10.10 
10.72 
16.60 



0.49 

0-53 
2.08 
0.94 

3-57 
2-57 
3-5° 
1.60 
2.78 



* Canadian Dept. of Inland Rev., Bui. 59. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 



357 





Starch, 

Fiber. 

etc., by 

Differ- 
ence. 


Maltose. 


L-tosa. gCa-, 


Remarks. 


Farinaceous foods: 

Imperial granum 


76.60 
72.01 
69.24 
78.66 

15.68 
47-72 










Ridge's food 










Mother's food 






3.00 


Corn and wheat starch 
Barley starch 


Robinson's barley 






Mixed foods: 

Horlick's malted milk 


49.00 
50 to 60 


30.00 


8.00 
Trace 


Lactated food 


Wheat starch 


Mellin's food 


Nestle's milk food 


35-34 
34-54 


8.96 
30.00 


36-34 
8 to 9 




Reid & Carnrick 's baby food . . . 





Diabetic Foods.. — Gluten flour and similar preparations are primarily 
intended for the use of diabetics, from whose dietary carbohydrates must 
be excluded. 

The following analyses of commercial gluten preparations were made 
bv Woods and Merrill.* 



"Cooked gluten" 

Whole-wheat gluten . . 

"Glutine" 

Breakfast cereal gluten 
Plain gluien flour .... 
Self-raising flour 



Protein. 



16.88 
17.89 
15-31 
43-70 

S3 -60 

31-50 



Fat. 



.86 
.20 

■99 
.60 
.20 
.40 



Carbohy- 
drates. 



76.80 

73-85 
82.52 
44.40 
34.50 

53-20 



Ash. 



2.46 
3.06 
1. 17 
0.70 
0.60 
3-80 



Many brands of gluten flour are put on the market by dealers in so- 
called "health foods," and in many cases are represented to be practically 
free from starch. Thirteen samples of gluten flour were analyzed by 
the author in 1899, varying in price from 11 to 50 cents per pound. Of 
these, 3, the product of one manufacturer, contained less than 1% of 
starch, 3 contained from 10 to 20 per cent, while 7 contained from 56 to 
70 per cent of starch, the substance which, of all others, the diabetic patient 
tries to avoid. Some of these preparations were little better than whole- 
wheat flour. An analysis of one of them, known as " Pure Vegetable 
Gluten," and sold for 50 cents per pound, and of two similar diabetic 
flours reported by Winton follow: 



* Maine Exp. Sta. Buls. 55 and 75. 



358 



FOOD INSPECTION AND ANALYSIS. 



" Pure Vegetable 
Gluten." 

Moisture lo . 78 

Ash 2.20 

Fat 3.25 

Protein 14-25 

Crude Fiber 

Sugars J - 70 I 

Dextrin 2.55 \ 

Starch 56.55 J 

Undetermined 8.72 



100.00 



■ Diabetic 
Food." 

12.67 

0-43 
0.90 

11-37 
0.25 

71-51 

2.87 

100.00 



" Diabetic 
Flour." 

9.26 
1.30 
2.21 
14-25 
1.03 

66.63 

5-32 
100.00 



Winton has reported the following analyses of flours and meals well 
suited for the preparation of diabetic biscuit, and of the biscuit made 
from two of these by a cook in the family of a diabetic patient: 



Gluten flour .... 
Gluten biscuit. . . 
Soja bean meal . . 
Soja bean biscuit 

Casoid flour 

Almond meal . . . 



25-58 



In original 

Calc. water-free 

In original 

Calc. water-free 

In original i 7-75 

Calc. water-free. . . 

In original 27.66 

Calc. water-free 

In original 

Calc. water-free 

In original 

Calc. water-free 



0.24 

2-35 
3. 16 

4.38 
4-75 
5-33 
7-37 
2.46 

2-73 
6.42 
7.02 



.5X 

u 

a, 



85-38 
95.00 

50-91 
68.41 
39-87 
43.22 
16.71 
23.10 
85.56 
95.08 
50.62 
55-32 



0.03 
0.03 
0.64 
0.86 
3-85 
4.17 
1-55 
2.14 



2.86 
3.12 



P X 



3-69 
4. II 

3.18 

4-27 
25.09 

27.20 

12.84 
17-75, 



1^ 



15.96 
17-45 



0.56 

0.62 

17-34 

23-30 
19.06 
20.66 

35-91 

49-64 

0.50 

0.56 

15-63 
17.09 



3 X 

"1 



4.46 
4-96 



8.95 
9.70 



none 
none 
7.18 
7-85 



In the analysis of diabetic foods, the determination of starch, sugar 
and dextrin together is of greater value than of starch alone, since all 
three classes of carbohydrates are about equally injurious to diabetics, 
the starch and dextrins being converted into sugars by the digestive 
fluids. The nitrogen-free extract of cereal preparations corresponds 
closely with the sum of the starch, sugar and dextrin, but in the case 
of soja bean meal, almond meal and other products of legumes and oil 
seeds, as well as vegetables, it is considerably greater, as it includes 
pentosans and other substances. 



CERE/4LS, LEGUMES, VEGETABLES, AND FRUITS. 359 

METHODS OF ANALYSIS. 

The sample is prepared for analysis by grinding it sufficiently fine in 
a mortar or mill to pass through a i-mm. sieve. Moisture, fat, ash, and 
nitrogen are determined as in the regular methods for cereals (pp. 277, 278). 

In determining loss of weight due to solubility of the sample in alcohol 
and water, proceed as follows:* The fat-free residue left in the Soxhlet 
apparatus, after extraction with ether or petroleum ether, is subjected 
to further extraction with g^^/c alcohol, till all soluble matter has been 
extracted. If 5 grams of the sample were originally taken for the fat 
extraction, this operation would require about five hours. Evaporate the 
alcoholic extract to dr}-ness, and weigh the residue as in the case of the 
ether extract. T)r\ the residue left in the Soxhlet from the alcoholic 
extract, or a portion thereof, in a platinum dish over the water-bath, 
cool, and weigh. Transfer to a Gooch crucible, provided with asbestos 
and previously tared, a portion, the relation of which to the original weight 
taken is calculated from the moisture, ether, and alcohol extracts as pre- 
viously determined. Pass through the contents in the Gooch by suction 
from 200 to 300 cc. of cold water at room temperature, dr\^ the Gooch 
and its contents at 100° to constant weight, cool and weigh, thus deter- 
mining the solubility of the sample in water. 

According to McGiU, five hours' extraction with alcohol under the 
above conditions removes all cane sugar, but probably not all the lactose, 
maltose, and dextrose, if a considerable quantity of these sugars is pres- 
ent. Water dissolves the dextrin and gum and such of the sugar as 
escapes solution in the alcohol, hence the sum of the alcohol and water 
extract is of value. In the calculation of the starch, fiber, etc., by diflfer- 
ence, it should be borne in mind that the result is only approximate, by 
reason of the fact that the small amount of soluble albuminoids (which 
McGill states never exceeds 2^^) are reckoned in, hence a small error 
is introduced, which could be corrected, if considered worth while, by 
determining the amount of soluble albuminoids. 

Separation of the Carbohydrates can be effected by Stone's method 
(pp. 295, 296), but a ver}- satisfactor}- idea of the solubility of these 
foods, which is of chief importance, can be gained by the much simpler 
modified method of McGill, as described in the preceding paragraphs. 

* McGill, Canada Inland Rev. Dept., Bull. 58. 



360 FOOD INSPECTION AND /ANALYSIS 

Starch, Sugar, and Dextrin are determined together in diabetic 
preparations by the diasta.^ method fp. 283) omitting the preliminary 
washing with dilute alcohol. 

Cold-water Extract.— The equivalent of 10 grams of the moisture-free 
substance, fmely ground, is weighed in a tared flask, and water added in 
several portions with gentle shaking till the contents of the flask weigh 
no grams. The flask is then corked and vigorously shaken at intervals 
during six or eight hours and allowed to stand over night. The super- 
natant liquid is then decanted into the large tubes of a centrifuge, and 
whirled till the sediment settles out. The comparatively clear liquid may 
then be readily filtered. 20 cc. of the filtrate, corresponding to 2 grams 
of the original sample, are then transferred to a tared dish, evaporated to 
dr)'ness, and dried to constant weight, as in the determination of the 
total sfjlids. 

Additional information may be gained from the specific gravity of 
the 10% solution of the cold-water extract, best obtained by means of a 
pycnometer. 

Reducing Sugars are determined in an aliquot part of the above 10% 
solution, diluted to proper strength. 

Effects of Subsequent Heating. — It is hardly fair in the case of those 
farinaceous foods which, according to directions, are to be subsequently 
subjected to heating, or boiling with water or milk, to condemn them as 
containing much insoluVjle matter, without comparing the figures express- 
ing results of the analyses of the raw foods, calculated to the water-free 
basis, with those obtained on analyzing the food after boiling or otherwise 
cooking with pure distilled water, for a length of time specified in the direc- 
tions, and afterwards drv'ing. It is possible that the presence in the food 
of diastase, or other ferment, may be depended on to hydrolyze a whole 
or a portion of the starch, and only by such comparison will this be shown. 

Microscopical Examination of the food is of value in determining 
its general character, showing especially w'hether or not starch is present 
in its original form, or has been converted in whole or in part. The par- 
ticular varieties of cereal grain employed are generally evident, as well 
as the presence and proportion of the different tissues of the grain. 



CEREALS. LEGUMES, VEGETABLES, AND FRUITS. 361 



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Wheat and Flour Investigations. Minn. Agric. Exp. Sta., Bui. 85, 1904. 



CEREALS, LEGUMES, VEGETABLES, AND FRUITS. 36^ 

Snyder, H. The Proteids of Wheat Flour. Minn. Agric. Exp. Sta. Bui. 63, p. 519. 

Report on the Bleaching of Flour. Dec. 28, 1906. 

Snyder, Frisby, and Bry.\nt. Losses in Boiling \^egetables. Exp. Sta. Bui. 43 
Sn\'DER, H., and Voorhees, M. A. Studies on Bread and Bread-Making. Exp. Sta. 

Bui. 67. 
Stone, W. E. Carbohydrates of Wheat, Maize, Flour, and Bread. Action of Enzjines 

on Starches. Exp. Sta. Bui. 24. 
The Quantitative Determination of Carbohydrates in Food Stufts. Jour. Am. 

Soc, 19, 1897, p. 347. 
Thatcher, R. W. A Comparison of \'arious Methods of Estimating the Baking 

Qualities of Flour. Jour. Am. Chem. Soc, 29, 1907, p. 910. 

Wheat and Flour Investigations. Washington Agric. Exp. Sta. Bui. 84. 

TscHlRCH, A., und Oesterle, O. Anatomischer Atlas der Pharmakognosie und 

Xahrungsmittelkunde. Leipzig, 1893. 
VoGL, A. E. Verfalschungen und \'erunreinigungen des Mehles und deren Xach- 

weisung. Wien, 1880. 
Die wichtigsten vegetabilischen Xahrungs- und Genussmittel. Wien u. Leipzig, 

1899. 
W.A-NKLYN, J. A., and Cooper, W. J. Bread Analysis. London, 1886. 
Wiley, H. W. Sweet Casava. Div. of Chem., Bui. 44. 
Analysis of Cereals Collected at the World's Columbian E.xposition. Div. of 

Chem., Bui. 45. 

Composition of Maize. Div. of Chem., Bui. 50. 

Wiley, H. W., et al. Cereals and Cereal Products. Div. of Chem., Bui. 13, Part IX. 
Winton, a. L. The Microscopy of \'egetable Foods. X'ew York, 1906. 

Diabetic Foods. An. Rep. Conn. Exp. Sta. 1906, p. 153. 

A Modification of the Bamihl Test for Detecting Wheat Flour in Rye Flour. 

A. O. A. C. Proc, 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 217. 
Winton, A. L., and B.^iley, E. M. On the Composition of American Xoodles and 

Methods for the Analysis of Xoodles. An. Rep. Conn. Exp. Sta., 1904, p. 138; 

Jour. Am. Chem. Soc, 37, 1905, p. 137. 
Winton, A. L., and Ogden, A. W. Macaroni, Sphaghetti, Vermicelli, and X'oodles. 

An. Rep. Conn. Exp. Sta., 1901, p. 196. 
Winton, A. L., and Sh.\nley, E. J. Simple Tests for Detecting Bleaching in Flour. 

A. O. A. C. Proc, 1908, p. 216. 
Woods and Merrill. Digestibility and X'utritive Value of Bread. Exp. Sta. Bui. 85. 
Arkansas Exp. Station Bui. 42. Wheat and its Mill Products. 
California " " '* 93. Oranges and Lemons. 

" " " " loi. Prunes, Apricots, Plums, Xectarines. 

" 102. Figs. 
" " '• An. Reports, 1892 et seq. 

Maine Exp. Station Bui. 54. Xuts as Food. 

" " " "55- Cereal Breakfast Foods. 

" " " "75- Analyses of Self-raising Flours, Pea Flours, Gluten 

Foods, Chestnuts, Malted Xuts. 
'« " " "84. Cereal Breakfast Foods. 



364 FOOD INSPECTION ^ND ANALYSIS. 

Minnesota Exp. Station Bui. 74. Digestibility and Food Value of Beans. 

Penn. Dept. of Agriculture Bui. 10. Special Report on Prepared Foods for Infants 

and Invalids. 
Wyoming Exp. Sta. Bui. 2,3,- Composition of Prepared Cereal Foods. 



REFERENCES ON LEAVENING MATERIALS. 

Bryan, T. J. The Carbon Dioxide Value of Pure Compressed Yeast and Starch 

Compounds. A. O. A. C. Proc, 1907, U. S. Dept. of Agric, Bur. of Chem., Bui. 

116, page 25. 
Catlin, Chas. a. Baking Powders, with Special Reference to Phosphate Powders. 

Providence, 1899. 
Crampton, C. a. Baking Powders. Div. of Chem., Bui. 13, Pt. 5. 
Green, J. R. Die Enzyme. Berlin. 

The Soluble Ferments and Fermentation. 1901. 

Hansen, E. C. Practical Studies in Fermentation. London, 1896. 
JORGENSEN, A. Die Mikro-organismen der Garungsindustrie. Berlin. 

Micro-organisms and Fermentation. London, 1900. 

Kenrick, G. B., and F. B. The Application of Polarimetry to the Estimation of 

Tartaric Acid in Commercial Products. Jour. Am. Chem. Soc, 24, 1902, 

page 928. 
Klocker, a. Fermentation Organisms. 1903. 

Lintner, p. Mikroskopische Betriebskontrolle in den Garungsgewerben. Berlin, 1895. 
McGiLL, A. Baking Powders. Canada Inl. Rev. Dept., Buls. 10, 26, 68. 

Cream of Tartar. Canada Inl. Rev. Dept., Buls. 12, 26, 71. 

Matthews, Chas. G. Manual of Alcoholic Fermentation. London, 1901. 
Oppenheimer, C. Trans, by Mitchell, C. A. Ferments and their Action. London, 

1901. 
Plummer, R. H. a. Chemical Changes and Products Resulting from Fermentation. 

London, 1903. 
Winton, a. L. Baking Powders. Bur. of Chem. Bui. 65, Part XV. Bui. 107, 

Part XXVI. 

Conn. Exp. Sta. An. Rep., 1900, page 15. 

Michigan Dairy and Food Commission, Bui. 2, page 12; Bui. 3, page 7. 

Penn. Board of Agriculture An. Report, 1897, page 166. 

North Carolina Exp. Sta., Bui. 155. 



CHAPTER XL 

TEA, COFFEE, AND COCOA. 
TEA. 

Nature and Classification. — Tea consists of the prepared leaves or 
leaf buds of Camellia Thea also known as Thea chinensis. 

The best teas are made from young leaves only, the Chinese teas 
being classified ^^^th reference to the age and position of the leaf on the 
young shoot. Thus, the ver\- choicest Chinese tea, rarely found outside 
of China, is prepared from the youngest or end leaves of the shoot, which 
are scarcely more than buds, and form the tea known as pekoe tip, or 
-flowery pekoe. The next leaves are the orange pekoe and pekoe, which 
produce a ven.' high grade of tea, while next in order as to age, size, and 
grade of leaf are the souchong ist and 2d, and the congou, producing 
teas called by the same names. 

More than 50*^ of the tea consumed in the United States comes from 
China, and over 40% from Japan, the remainder being derived largelv 
from India, Ceylon, and other East Indian ports. 

In the manufacture of tea the fresh leaves, which are nearly 80% water, 
are rolled, ^\•ithered by exposure to light, heat, and air, and finally dried 
or "fired" by treatment with artificial heat over charcoal fires, or in 
properly constructed furnaces. 

Teas are divided into two groups, black and green, which differ from 
each other, not as formerly supposed in being derived from different plants, 
but in their process of manufacture, the same species of plant furnishing 
both varieties. Genuine green tea is prepared by first steaming and 
afterwards drying the leaves while still fresh, thus retaining the brio-ht 
color. Black tea is allowed to undergo oxidation or fermentation bv 
exposure to the sun, which gradually turns the leaves black. Less tannin 
is present in black tea than in green. 

365 



366 



FOOD I\SPEC7JON /1ND ANALYSIS. 



Composition of Tea. — Konig gives the following composition of fully 
developed tea leaves, being the mean of 50 to 70 analyses: 



Water. 


Nitroge- 
nous Sub- 
stances. 


Theine. 


Essential 
Oil. 


Fat.Chlo- 

rophyl, 

and Wax. 


Gum, 

Dextrin, 

etc. 


Tannin. ^^f^^- 


Crude 
Fi ber. 


Ash. 


9-51 


24.50 


3-58 


0.68 


6.39 


6.44 


15.65 16.02 


11.58 


5-65 



Though the nitrogenous substances of tea predominate in amount 
over any other class of constituents, yet, with the exception of theine or 



^Xv^. 




Fig. 72. — <J, Flowery Pekoe ; b, Orange Pekoe; c. Pekoe; d. Souchong, ist; e, Souchong, 2d^ 
/, Congou; a, b (when mixed together), Pekoe; a, b, c, d, e (when mixed together), Pekoe 
Souchong. If there be another leaf below /, it is termed Bohea. At base of leaves 
are buds i, 2, 3, 4, from which new shoots spring. (After Money.) 

caffeine, they have been little studied. Theine, tannin, and essential 
oil give to the infusion of tea its chief characteristics. 

ZoUinski * gives the following summarized results of analyses of a 
number of the cheaper grades of Chinese black tea: 



* Zeits. anal. Chem., 1898, 37, 365. 



TEA, COf-FEE, AND COCOA. 



367 



Maximum . . 
Minimum . 
Average 



Water. 



"-57 

9.96 

10. ^8 



Total 
Nitrogen. 



4.12 
3-76 
3-93 



Albumin- | 
oid and Protein, 
Amido- N X 6. 2 5 . 
nitrogen. 



Theine. 



Ash. 



3-78 
3-37 
3-52 



23-83 
21.06 



2.06 
1. 14 



6.78 
4-79 
5-94 



Soluble Insoluble 
Ash. Ash. 



31-17 
28.13 
29.67 



61.03 
57-74 
59-75 



-\ ver}' complete series of analyses of tea was made by Joseph F. Geiss- 
ler in 1884,* from which the following summaries are taken: 







y 


^ ' 


J. i 




















Moistur 

Half-ho 
Extrac 


Total 
Extrac 

Insolubl 
Leaf. 


c 
c 


C 




Soluble 

Ash. 


J< 




Indian: 


Maximum. . 


6 


6.19 39.66 


45.64 53.07 18.86 


3-3 


5-79 


3-68 


2.22 


.296 




Minimum . . 




5.5637.8041.32 


48.53 13.04 


1.8 


5-42 


3-24 


1-93 


-137 




Average. . . . 




5.81:38.7742.94 


51-24 


14.87 


2-7 


5.62 


3-52 


2.12 


.178 


Oolong: 


Maximum.. 


13 


6.8844-0248.87 


53-15 


20.07 


3-50 


6. II 


3-71 


3-17 


.838 




Minimum . . 




5.0934.1040.6 


44-8 


11-93 


1-15 


5-44 


2.60 


1.84 


.266 




Average 




5.8937.8843.32 


.50-7 


16.38 


2.32 


S.81 


3-2 


2.68 


.507 


Congou: 


Maximum . . 




9.15 32.14 37.06 


63-85 


13.89 


2.87 


6.48 


3-52 


3-86 1. 31 




Minimum . . 




7.65 23.48^27.48 


54-5 


8.44 


1.70 


5-52 


2.28 


1.90! .32 




Average 




8.3728.40:34.35 


57-2 


11-54 


2-37 


5-75 


3-06 


2.68 .425 



Kenrick j gives the following averages of a series of analyses of tea 
made by him in 1891: 




Substances Extracted 

by 10 Minutes' 

Infusion. 



Congou tea lo 

Assam tea : 3 

Ceylon tea j 2 

Unclassed black 13 

Japan i 18 

Gunpowder j 2 

Young Hyson I 5 





I 




■ — 


aJ-.S 








= C« 




H 


H 


23-37 


5.18 


.S8.53 


7-49 


27-45 


7-85' 


23-76 


5-40! 


30.07 


9-381 


28.55 


8.00' 


34-22 


io.98| 




The ash of many genuine teas has been e.xamined by Battershal + 
with the following results: 

* Am. Grocer, Oct. 23, 1884. 

■j- Canada Inland Rev. Dep. Btd. 24. 

X Food .\dulteration and its Detection. 



36S 



FOOD INSPECTION AND ANALYSIS 



Oolong. 

Average of so 

Samples. 




Total ash 

Soluble in water 
Per cent soluble. 



COMPOSITION. 



Silica 

Chlorine 

Potash 

Soda 

Ferric oxide 

Alumina 

Manganic oxide. 
Lime 

Magnesia 

Phosphoric acid. 
Sulphuric acid . . 
Carbonic acid. . , 



6.04 

3-44 
57.00 



11.30 

1-53 

37-46 

1.40 

1.80 

S-13 
2. 10 

9-43 
8.00 
12.27 
4.18 
5-40 



5-55 
3.60 

64.55 



9-30 

1.60 

41.63 



1. 12 
4.26 
1.30 
8.18 

5-33 
16.62 

3-64 

5-9° 



2.52 

0.28 

II. II 



27-75 
0.79 



16.00 

19.66 

11.20 

15.80 

1. 10 

6.70 



99.00 



Kozai * gives the following as the results of analyses made by him of 
Japanese teas: 



Unprepared 
Leaves. 



Caffeine or theine 

Ether extract 

Hot-water extract 

Tannin (as gallotannic acid) 
Other nitrogen-free extract . 

Crude protein 

Crude fiber 

Ash 

Albuminoid nitrogen 

Caffeine nitrogen 

Amido-nitrogen 

Total nitrogen 



3-30 
6.49 

50-97 
12.91 
27.86 

37-33 
10.44 

4-97 
4. II 
0.96 
0.91 
5-97 



Green 
Tea. 



Black 
Tea. 



3-30 

5.82 

47-23 
4.89 

35-39 
38.90 
10.07 

4-93 
4. II 
0.96 
1. 16 
6.22 



PROXIMATE COMPONENTS AND ANALYTICAL METHODS. 

Preparation of Sample. — Grind the material so as to pass a sieve 
with holes 0.5 mm. in diameter. 

Moisture, Ether Extract, and Crude Fiber are determined in the 
same weighed portion of 2 grams, following the methods described under 
cereals (p. 277). 

* Bui. 7, Imperial College of Agriculture, Japan. 



TEA, COFFEE, AND COCOA. 369 

Protein. — Determine total nitrogen by the Kjeldahl or Gunning 
method; from this subtract the nitrogen due to caffein (obtain by dividing 
by 3.464) and multiply the difference by 6.25. 

Total Ash. — -Burn 2 grams of the material to a white ash in a 
platinum dish at a faint red heat. The total ash of pure tea should not 
be less than 4 nor more than y'^. 

Soluble and Insoluble Ash.* — The total ash, as obtained above, is 
transferred to a beaker with hot water and boiled for some time, after 
which it is poured upon a filter and the residue washed with hot water. 
The residue is then dried, ignited at a faint red heat in a platinum dish, 
cooled, and weighed, thus giving the amount of insoluble ash. The 
soluble ash is calculated by difference from the total and insoluble ash. 

Ash Insoluble in Acid.* — The portion of the ash insoluble in water 
is washed upon a tared filter with hot 10 S"^ hydrochloric acid and further 
washed with the latter reagent till the acid-soluble matter is dissolved 
out, after which it is washed with water, dried, and weighed. 

Alkalinity of Ash.* — This is expressed in terms of cc. of tenth- 
normal acid required for the ash of i gram of sample. 

Soluble Ash. — Cool the filtrate from the determination of insoluble 
ash, as described above, and titrate with tenth-normal hydrochloric acid, 
using methyl orange as an indicator. 

Insoluble Ash. — Add excess of tenth-normal hydrochloric acid (usually 
10 to 15 cc.) to the ignited insoluble ash as obtained above in the platinum 
dish, heat to the point of boiling over an asbestos plate, cool, and titrate 
excess of hydrochloric acid with tenth-normal sodium hydroxide, using 
methyl orange as an indicator. 

Essential Oils.— Distil 100 grams of the tea with 800 cc. of water, 
and shake out the distillate with several portions of ether. The residue 
from the combined ether extracts contains the volatile oil. 

Insoluble Leaf.f — Boil 2 grams of the tea in a 500-cc. Erlenmeyer 
flask over a low flame with 200 cc. of water, replacing from time to time 
by addition of hot water the loss from evaporation. Filter through a 
tared filter, and wash the residue until the filtrate measures 500 cc, 
stirring the contents of the filter throughout the process to facihtate 
filtering. Reserve filtrate for determination of tannin and theine. Dry 
the filter and residue until dry to the touch, transfer to the weighing 
bottle, and dry to constant weight at 100° C. If the amount of insoluble 

* A. O. A. C. Method, U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 69. 
t Doolittle and Woodruff, A. O. A. C. Proc. 1906, U. S. Dept. of Agric, Bur. of Chem., 
Bui. 105, p. 48. VVinton, Ogden and Mitchell, Conn. Exp. Sta. An. Rep., 1898, p. 132. 



370 



FOOD INSPECTION AND /IN A LYSIS. 



leaf is above 60%, the presence of spent or exhausted leaves may be 
suspected. 

Extract. — By this term is meant the total amount of water-soluble 
matter in tea, including such compounds as tannin, caffeine, albuminous 
matter, dextrin, gum, certain parts of the ash, etc. 

The value of a tea from a food standpoint depends obviously upon 
the character and amount of the extract, rather than on the composition 
of the dry tea. The relative composition of the extract and of the insoluble 
leaf, as found by Eder, is given in the following table. 





Extract. 


Insoluble 
Leaf. 


Dry matter 


Per Cent. 
40. 
12. 


Per Cent. 
60. 
12.7 

7.2 
10. 

2-3 

0.29 
0.58 

1-03 
0.68 


Nitrogenous substances 


Theine 

Tea oil 


2. 
0.6 


Resin, chlorophyll, etc 


10. 
12. 

1-7 

0.94 

0.04 

0-13 

0.21 


Tannin 


Extractives 


Ash 


Potash 


Lime 


Phosphoric anhydride 


Silica 





Determination. — The sum of the percentages of insoluble leaf and 
moisture subtracted from 100 gives the percentage of extract. 
Tannin. — Proctor's Modification of LowenthaVs Method.^ 
Reagents: (i) Potassium permanganate solution containing about 
1.33 grams per liter. 

(2) Tenth-normal oxalic acid solution (6.3 grams per liter). 

(3) Indigo carmine solution, containing 6 grams indigo 

carmine (free from indigo blue) and 50 cc. concen- 
trated sulphuric acid per liter. 

(4) Gelatin solution, prepared by soaking 25 grams gela- 

tin for an hour in a saturated sodium chloride solu- 
tion, heating till the gelatin is dissolved, and mak- 
ing up to a liter after cooling. 

(5) Mixture of 975 cc. saturated sodium chloride solution 

and 25 cc. concentrated sulphuric acid. 

(6) Powdered kaolin. 

Obtain the value of the potassium permanganate solution in terms 
of the tenth- normal oxalic acid solution. 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 7, p. 890; Bui. 107 (rev.), p. 150. 



TEA, COFFEE, AND COCOA. 371 

Boil 5 grams of the powdered tea for half an hour with 400 cc. of water, 
cool, transfer to a graduated 500-cc. flask, and make up to the mark. 
To 10 cc. of the infusion (filtered if not clear) add 25 cc. of the indigo 
carmine solution and about 750 cc. of water. Then add from a burette 
the potassium permanganate solution, a little at a time while stirring, 
till the color becomes light green, then cautiously drop by drop till the 
color changes to bright yellow,* or further to a faint pink at the rim. 
The volume in cubic centimeters of permanganate furnishes value a of 
the formula. 

^lix 100 cc. of the clear infusion of tea with 50 cc. of gelatin solution, 
100 cc. of salt acid solution, and 10 grams of kaolin, and shake several 
minutes in a corked flask. After settling, decant first the clear super- 
natant liquid through a filter, and finally bring the precipitate upon the 
filter. Mix 25 cc. of the filtrate (corresponding to 10 cc. of the original 
infusion) with 25 cc. of the indigo carmine solution, and about 750 cc. 
of water, and titrate with permanganate as before. The volume in cubit 
centimeters of permanganate used gives value h. 

a = quantity of permanganate solution required to oxidize all oxidiz- 
able substances present. 

6 = quantity of permanganate solution required to oxidize substances 
other than tannin. 

.'. a—b = c, permanganate required for the tannin. Assuming that 
0.04157 gram tannin fgallotannic acid) is equivalent to 0.063 gram oxalic 
acid, the tannin in the tea is readily calculated. 

As recommended by Doolittle and Woodrufff the determination 
may be conveniently made on aliquot portions of the solution obtained 
in the determination of insoluble leaf. 

Method of Fletcher and AUen.% — This method depends upon the pre- 
cipitation of the tannin and other astringent matters in tea infusion by 
lead acetate, the point of complete precipitation being indicated by an 
ammoniacal solution of potassium ferricyanide. 

Five grains of neutral lead acetate are dissolved in water, made up to 
I liter, and after standing the solution is filtered. 

As an indicator, 0.05 gram of pure potassium ferricyanide is dis- 
solved in 50 cc, of water, and an equal volume of concentrated ammonia- 

* Various shades of color may be produced, but the same shade should obviously be 
adopted as an end-point by the operator as when standardizing. 

t A. O. A. C. Proc. 1906, U. S. Dept. of Agric, Bur. of Chem., Bui. 105, p. 49. 
X Chem. News, XXIX, 169, 189. 



372 FOOD INSPECTION ^ND ANALYS'iS. 

water is added. This indicator produces a red coloration with tannin, 
gallic acid, or gallotannic acid in solution, being so sensitive that 
a drop of the indicator will detect i part of tannin in 10,000 parts of 
water. 

Three separate quantities of 10 cc. each of the standard lead acetate 
solution, as above prepared, are measured into as many beakers, and each 
diluted to 100 cc. with boiling water. Two grams of powdered tea are 
boiled in 250 cc. of water, and varying quantities of this decoction are 
measured from a burette or pipette into the beakers containing the lead 
solution, the first beaker receiving, say, 12 cc, the second 15 cc, and 
the third 18 cc, in the case of black tea, and, with green tea, 8, 10, and 
12 cc, respectively. 

About I cc of each of these trial quantities is removed from the 
various beakers by means of a pipette, passed through small filters, and 
tested with the ammoniacal ferricyanide indicator, the drops of filtered 
solution being allowed to fall directly on spots of the indicator, previously 
placed on a white slab or plate. 

It is thus easy to ascertain the approximate amount of tea solution 
which it is necessary to add to produce a pink coloration with the indi- 
cator, so that by repeated tests, nearly the right amount may be added 
at once. If no coloration in a given case is produced when a drop of 
the filtrate from the solution in the beaker is allowed to fall on the drop 
of indicator solution, a little more of the tea decoction is added, and this 
process is repeated until the pink color is apparent. 

It should be noted how much of the tea decoction is necessary to add 
to 100 cc of pure water, that a drop of the solution may produce the pink 
coloration with the ferricyanide, and this amount should be subtracted 
from the amount of decoction found necessary to add to the known lead 
solution in the beaker. It was found by repeated experiment that 10 cc 
of lead solution would precipitate 0.0 1 gram of pure gallotannic acid; 
hence, carrying out the process exactly as above described, 125 divided 
by the number of cubic centimeters of tea decoction required gives the 
percentage of tannin in the sample.* 

Theine or Caffeine (C8H10N4O2). — This alkaloid when pure exists 
in white silky needles. It is odorless and sparingly soluble in cold water, 



tannm. 



' This process estimates the total astringent matter, all of which is counted in as 



TEA, COFFEE, AND COCOA. 373 

but more so in hot. It is less soluble in alcohol, and almost 
insoluble in ether. It readily dissolves in chloroform. It is present 
in tea, coffee, and kola. Graf* has shown that the amount of caf- 
feine present in tea is in most cases proportional to the commercial 
value and quahty. 

Detection. — Caffeine may be detected, if present in a suspected residue, 
by the so-called " murexid test," which is made with the material in a 
sohd state, or with the residue from the evaporation of a hquid. A small 
quantity of the sohd or powdered material is heated in a white porcelain 
dish and covered with a few drops of strong hydrochloric acid, after which 
a fragment of potassium chlorate is immediately added. The mixture 
is then evaporated to complete dr}Tiess on the water-bath, whereupon, 
if caffeine is present, a reddish-yellow or pink color is produced. After 
cooling, the residue is treated with a very little ammonia water 
apphed on the point of a stirring-rod. In the presence of caffeine, a 
purple color (that of murexoin) is produced on application of the 
ammonia. 

Determination of Theine or Caffeine. — Dvorkovitsch Method. -\ — 
Digest 10 grams of the powdered tea with 200 cc. of boiling water for 
5 minutes and decant the solution; repeat the treatment twice, and boil 
the residue with 200 cc. of water. Make up the combined solutions to 
1000 cc. and extract a portion with petroleum ether to remove fat, etc. 
To 600 cc. of the fat-free solution (equivalent to 6 grams of tea) add 100 
cc. of 4^ barium hydroxide solution, mix and filter. To 583 cc. of the 
filtrate (equivalent to 5 grams of tea) add 100 cc. of a 20^ solution of 
sodium chloride, and extract three times with chloroform. Distil the 
greater part of the chloroform from the combined extracts, place the 
residue in a tared dish, evaporate the remainder of the chloroform, dry 
at 100° C, and weigh. The caffeine is usually of sufficient purity to 
render a nitrogen determination unnecessar}'. 

Doolittle and Woodrufft proceed as follows: Extract in a separating 
funnel with petroleum ether 225 cc. of the filtrate from the determi- 
nation of insoluble leaf (p. 369) made up to 500 cc. To the fat-free 
portion add 50 cc. of a 4-"c barium hydroxide solution, shake well, 



* Forsch, Ber., 4, 1897, pp. 88, 89. 

t Ber. d. chem. Ges., 24, 1891, p. 1945; U. S. Dept. of .\gric., Bur. of Chem., Bui. 107 
(rev.), p. 150. 
+ loc. cit. 



374 FOOD INSPECTION /tND ANALYSIS. 

and filter. To the tiltrate add 50 cc. of a 20% sodium chloride solution 
and proceed as above described. 

Modification of Stahlschmidfs Method. — Six grams of finely powdered 
tea are boiled in a flask with several successive portions of water for ten 
minutes each, and the combined aqueous extracts thus obtained are made 
up to 600 cc. with water. Four grams of powdered lead acetate are 
added to the decoction, which is then boiled for ten minutes, using a 
reflux condenser, or making up the loss by occasional addition of water. 
The solution is then poured upon a dry filter, and 500 cc. of the filtrate, 
corresponding to 5 grams of the tea, are evaporated to about 50 cc. and 
enough sodium phosphate added to precipitate the remaining lead. The 
solution is then filtered, and the precipitate thoroughly washed, the 
filtrate and washings being evaporated to about 40 cc. Finally, the 
solution thus concentrated is extracted with chloroform in a separatory 
funnel for at least four times, and the chloroform extract evaporated 
to dryness, leaving the caffeine, which is dried to constant weight at 
75° and weighed. 

ADULTERATION OF TEA. 

Facing. — The most common form of lea aduUeralion, if such it may 
be called, is the practice of "facing" the dried leaves, or treating them 
with certain pigments and coloring materials to impart a bright color 
or gloss to the tea, thus causing an inferior grade to appear of better 
quality than it really is. This practice is more often apphed to green 
tea. The materials for facing include such substances as Prussian blue, 
indigo, plumbago, and turmeric, often accompanied by such minerals 
as soapstone, gypsum, etc. Only a small amount of foreign material is 
actually added 10 the tea, but the adulteration consists in the deceptive 
appearance imparted thereto. 

Battershal has examined various samples of the preparations used 
in Japan for facing tea. He found in one case the following compo- 
sition: Soapstone, 47.5%; gypsum, 47.5%; Prussian blue, 5%. An- 
other sample consisted of soapstone, 75%; indigo, 2^%. A third was 
composed of soapstone, 60%, and indigo, 40%. In applying the facing 
to the tea, the latter is first heated in an iron pan over the fire, the facing 



TEA, COFFEE, AND COCOA. 375 

mixture is then added while still hot, and the whole is stirred briskly till 
the desired color is imparted. The Chinese and Japanese do not face 
the tea which they themselves consume, but only that intended for export 
trade. 

The microscope furnishes the most ready means of detecting tur- 
meric and plumbago. The latter is detected by the bright glossy parti- 
cles, evident when a thin section of the tea leaf is examined^ under the 
microscope. 

Prussian blue and indigo are also evident by the microscopical appear- 
ance of the particles, detached by shaking the leaves in water. Prussian 
blue or ferric ferrocyanide is detected by the transparent bright-blue 
particles, while indigo, when viewed under the microscope, is more of 
a greenish blue. The detached particles of coloring matter often rise to 
the surface of the liquid, when the leaves are shaken in hot water, and 
for microscopical examination may be floated upon a glass slide. The 
color of Prussian blue is discharged by treatment with sodium hydroxide, 
while that of indigo is not. Prussian blue, if present, may be chemically 
detected in the sediment as above obtained, by dissolving in hot alkali, 
acidifying with hydrochloric acid, and then adding a drop of ferric chloride. 
A blue precipitate is indicative of the ferric ferrocyanide. 

Such minerals as gypsum and soapstone are readily separated as a 
sediment by shaking the leaves in water, and the sediment is examined 
by the appropriate qualitative methods for these substances. 

Spent or Exhausted Leaves. — These consist of leaves of tea that have 
been previously steeped or infused, and afterwards rerolled and dried. 
Such leaves are sometimes mixed with tea as an adulterant. Any con- 
siderable admixture of spent leaves is evident, both by the extremely low 
ash, and the abnormally small proportion of water-soluble ash in the 
sample. It is rare that the total ash of genuine tea is under 5%, while 
the soluble ash is seldom less than 3%. 

The ash of spent tea leaves sometimes runs as low as 2.5%, of which 
generally not more than 0.3 to 0.8 per cent is soluble. Spent leaves are 
also naturally low in tannin and in extract. 

If the extract is much below 32%, spent leaves may be suspected. 
Allen has suggested the following formula for determining the percent- 
age of spent leaves, E, in a sample of tea, R being the percentage of 
extract: 

(32 -i?) 100 
£,= — — • 

30 



376 



FOOD INSPECTION /IND yiNALYSIS. 



The use of spent or exhausted leaves as an adulterant is very rare 
at present, though formerly of common occurrence. 

Foreign Leaves as a Substitute for Tea.— This sophistication is not 
common, but the detection of leaves other than tea is readily accom- 
phshed by a careful examination of the shape and character of the leaves. 
For this purpose the dried leaves are opened out by soaking a short time 
in hot watef, after which they are spread upon a glass plate, and examined 
by the aid of a magnifying-glass. 

The genuine tea leaf (Fig. 73) is ver}^ characteristic, and is readily 
distinguished from other leaves. It is oval or lanceolate, 5 to 8 cm. long 

and 2 to 3 cm. wide. It is short-stemmed, 
somewhat thick and fleshy, attenuated at the 
bottom and usually pointed at the top. At a 
certain height from the base, from a third to 
a quarter up, the smooth or wavy border be- 
comes pecuharly, though not deeply, serrated in 
a regular manner, the serrations, which are 
hook-shaped, continuing to the tip of the leaf. 
Mature leaves always show these serrations, 
but they are somewhat obscure in young leaf 
buds. The latter, however, are rarely found 
in this country. The veins extend outward 
from the central rib nearly parallel to each 
other, but before reaching the border, each 
bends upward to form a loop with the one 
above. 

Foreign leaves, said to be used as adulter- 
ants, are those of the willow, poplar, elder, 
birch, elm, and rose, but the writer has never 
found any of these in tea. All of them differ 
materially from the genuine tea leaf, and if 
foreign leaves are apparent in a sample under 
examination, they should be compared with various leaves collected by 
the analyst for the purpose. 

Stems and Fragments. — These, as well as ''tea dust," are apparent 
by an examination of the leaves, opened out in hot water as explained 
above. The ash of tea stems and dust is abnormally high. The 
term "He tea" is apphed to an imitation of tea, consisting of fragments, 
stems, and tea dust, mixed with foreign leaves, mineral matter, gum, etc. 




Fig. 73. — The Leaf of 
Genuine Tea. 



TEA, COFFEE, AND COCOA. 377 

The ash of such "tea" has been found as high as 50%. Such miita- 
tions are now almost unknown. Make-weight substances, such as brick- 
dust, iron salts, metalHc iron, sand, etc., have been found in tea. If 
present, they are to be found in the sediment, obtained on shaking out 
the tea in water. 

Added Astringents. — Catechu is sometimes said to be added to tea 
to give it increased astringency, especially to such tea as has been adulter- 
ated by the addition of exhausted tea. Hagar's method for detecting 
catechu is as follows: 

A hot-water extract of the tea (i to lod) is boiled with an excess of 
litharge and filtered. To a part of the filtrate, which should be perfectly 
clear, nitrate of silver is added. If catechu be present, a yellow floc- 
culcnt precipitate, rapidly becoming dark-colored, is formed. Pure tea 
treated in Hke manner gives a gray precipitate- 
Spencer * adds, instead of silver nitrate, a drop of ferric chloride to 
the clear filtrate. With catechu a green precipitate is formed. 

As a matter of fact the worst forms of tea adulteration, such as the 
actual substitution of foreign leaves, once so commonly practiced, are 
now extremely rare in this country and have been for some years, by reason 
of the careful system of government inspection in force at the various 
ports of entry. The greater portion of the tea on our market to-day is 
genuine, but fraud is practiced to a considerable extent by the substitu- 
tion of inferior grades for those of good quality. This form of deception 
is in many cases beyond the power of the analyst to detect, and properly 
comes within the realm of the professional tea-taster. 

Tea Tablets. — Finely ground tea of var}'ing quality is sometimes 
pressed into tablets, to be used by travelers and campers for preparing 
a beverage, by simply dissolving in hot water. 

The composition of one of these preparations sold under the name 
of Samovar Tea Tablets, analyzed by the Mass. State Board of Health, 
is as follows: 

Water 8.7 

Theine 2.25 ^ 

Extract 54.4 

Ash 5.4 

Soluble ash 2.8 

Insoluble ash 2.6 



* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 



378 



FOOD INSPECTION AND ANALYSIS. 



Microscopical Structure of Tea. — The powdered tea may be examined 
directly in water- mount. Schimper recommends treating the powdered 
tea with chloral hydrate or potash lye, to render it more transparent. 

By far the most characteristic element is the peculiarly shaped 
sclerenchyma, or stone cell, st, Fig. 74, entirely unlike anything to be found 
in other leaves. These cells are very irregular in form, being sometimes 
star-shaped, sometimes branched, almost always with deeply wrinkled sides, 




Fig. 74. — ^Powdered Tea under the Microscope. Xi6o. g, end of leaf nerve; p, chloro- 
phyll parenchyma; 5/, stone cells; h, hairs. The tissues were warmed in potash to 
render transparent. (After Moeller.) 

and often with sharp points. In most foreign leaves such sclerenchyma 
cells are lacking, but they are abundant in all genuine tea leaves, excepting 
rarely in the very young leaves, where they are sometimes not fully devel- 
oped. They are especially numerous in the main vein and in the stem. 
They may be seen to best advantage in a section of the stem, or midrib, 
made parallel to the surface of the leaf. To make such a section, soak 
the leaf first in water, and afterwards dry in alcohol. The interior of 
the leaf is composed chiefly of ground tissue, having rounded cells full 
of chlorophyll grains and the fibro- vascular bundles of the veins. 

Other important characteristics are the peculiar hair growth on the 
under epidermis, B, which is apparent in nearly all teas, also crystal 
rosettes of calcium oxalate, which are nearly always present, even in 
fragments of tea leaves, but not in all foreign leaves. The peculiar 
structure of the lower epidermis, B, with its numerous stomata is also to 
be noted. See Figs. i8q and 190, PI. XVIII. 



TE/t, COFFEE, AND COCOA. 379 



COFFEE. 

Nature of Coffee.— Coffee is the seed of the Cojfea arahica, a tree 
which, when under cultivation, is not allowed to exceed twelve feet in 
height, but when wild sometimes reaches a height of twenty feet. It is 
indigenous in Southern Abyssinia, and was cultivated in Arabia in the 
sixteenth century, and in the East Indies in the seventeenth, afterward 
being introduced into the West Indies and South America. The coffee^ 
beans are usually inclosed in pairs in the berry, being plano-convex with 
their flat sides together but in " pea berry " cotTee only a single, rounded 
bean is present. 

When the ripe fruit is gathered, it is first dried and then freed from 
the hulls, usually by machinery, or, in the West Indies, the green berries 
are "pulped" or "hulled" under water by a peculiar macerating machine. 
The raw beans are roasted, and afterwards ground for preparing the 
infusion. 

Brazil furnishes more than half the world's supply of coffee, and 
nearly 75% of that consumed in the United States. 

Composition of Coffee. — Most of the coffee in the retail market is ' 
roasted, being sold either in the whole bean or ground. Comparatively 
little raw coft'ee is sold at retail. 

The constituents of raw coft"ee, besides water, are, in the order of their 
comparative amounts, cellulose or crude fiber, fat, protein, caffetannic 
acid, sugar, caffein, gum, dextrin, and ash. The effect of roasting coffee, 
besides driving off most of the water, is to caramelize a large part of the 
sugar, to make the bean less tough and more brittle, and, most important 
of all, to develop an empyreumatic, oily substance, known as caffeol 
(CgHioOa), to which the characteristic flavor and aroma of coffee are 
largely due. Caffeol may be obtained by distilling an infusion of roasted 
coft'ee, and extracting the distillate with ether. It is a brown oil, almost 
insoluble in water. 

According to Genin, there are in raw coffee small amounts of two 
essential oils, one soluble in water, the other insoluble. During the 
roasting, these are partially transformed into the substance caffeol. 

The fat in coffee forms a considerable constituent, amounting in 
some cases to 15%. 

Caffetannic Acid (CisHigOg) is, when pure, a colorless, crystalline 
compound. It exists in coffee either as a salt of calcium or magnesium, 
or, according to Payen, as a caffetannate of potassium and caffeine. 



3 So 



FOOD INSPECTION AND ANALYSIS. 



The following summary of analyses of coffee of various kinds made by 
Konig show in general its composition: 



Raw Coffee. 



Minimum. 



Maximum. 



Roasted Coffee. 



Minimum. 



Maximum. 



Water 

Caffeine 

Fat 

Reducing sugar, 

Cellulose 

Total nitrogen. 
Ash 



8.0 
0.8 

II. 4 
5-8 

i6.6 



3-5 



12. 

1.8 
14.2 

7-8 
42.3 

2.2 

4.0 



0.4 
0.8 

10-5 

0.0 

26.3 

1-3 
4.0 



4.0 

1.8 

16.5 

I . I 

51.0 

2-7 

5-0 



The change in composition that takes place in roasting coffee is w^ll 
shown by the following figures, which give the mean of analyses by Konig 
of four samples of coffee before and after roasting: 



Raw Coffee. 



Water 

Caffeine 

Fat 

Sugar 

Cellulose 

Nitrogenous substances 

Other non-nitrogenous matter 
Ash 



11.23 

1 .21 

12.27 

8-55 
18.17 
12.07 
32-58 

3-92 



Roasted Coffee, 



I-15 

1.24 
14.48 

0.66 
10. Sg 
13.98 
45-09 

4-75 



COMPOSITION OF THE ASH OF COFFEE.* 



Constituents, 

Sand 

Silica (SiO.,) 

Ferric oxide (FeoO^). . . 

Lime (CaO) 

Magnesia (MgO) 

Potash (K,,0) 

Soda (Na,,b) 

Phosphoric acid (P2O5). 
Sulphuric acid (SO3). . , 
Chlorine (CI) 



Mocha. 



Maracaibo. 



Java. 



Rio. 



1-44 
0.88 
0.89 
7.18 
10.68 

59-84 
0.48 

12.93 
4-43 
1-25 



0.S8 

0.89 

5.06 

11.30 

61.82 

0.44 

13.20 

5.10 

0.59 



0.74 
0.91 
1. 16 
4-84 

11-35 
62.08 

14.09 
4.10 
0-73 



100.00 



I 00 . 00 



1-34 
0.69 

1-77 

4.94 

10.60 

63.60 

0.17 

11-53 
4.88 
0.48 



The following are analyses of common varieties of roasted coffee, 
also of coffee substitutes and adulterated coffee made by Lythgoeif 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 904. 

t An. Rep. Mass. State Board of Health, 1904, p. 3.10. U. S. Dept. of .^gric, Bur. of 
Chem., Bui. 90, pp. 43-45. 



TEA, COFFEE, AND COCOA, 



381 



COMPOSITION OF ROASTED COFFEE. 

















Alkalinity 


























(cc. N/io 


























Acid) of 








c 








3 

'0 


< 


< 

3 
"^ 

u 
v 

Id 


•0 
a 

ni 


<0 






6 

3 
1 


6 

3 
1 


U 

w 




H 

c 




Variety. 


E oi 
< 


< 
"0 
E 




c 

M 

2 

I 




[-^ 


1.40 


4.16 


3-46 


0.00 


0.023 


2-97 


71.4 


0.319 


0.346 


14-58 


1-4754 


2.26 


Santos 


^ 


1.87 


4 


31 


3-62 


.00 


.023 


3 


36 


75-7 


.286 


-295 


13-84 


1-4754 


2.26 




w 


I -31 


3 


80 


3.00 


.00 


.019 


3 


35 


85.6 


-273 


.295 


13.8b 


1-4750 


2-39 




A 


1.29 


4 


05 


5-30 


.00 


.016 


3 


53 


87.2 


•305 


•337 


13.00 


1-4752 


2.28 


Rico 


^ 


1.26 


4 


06 


3-27 


.00 


.020 


3 


72 


92.6 


.226 


-351 


13-34 


1-4750 


2.26 


c 


1.48 


4 


12 


3-32 


.00 


.016 


3 


66 


88.8 


-?<?,?, 


• 328 


14.12 


1.4760 


2.33 




A 


1.76 


4 


06 


3-40 


.00 


.020 


4 


16 


102.3 


.213 


.166 


13-38 


1-4758 


2.14 


Rio 


^ 


2.34 


3 


Qi 


3-24 


.00 


.021 


3 


17 


81.2 


.356 


.227 


13-71 


1-4753 


2.18 




c 


2.10 


3 


74 


3.06 


.00 


.023 


3 


22 


86.6 


-363 


• 236 


13-53 


1-4756 


2.26 




A 


2.05 


4 


05 


3-2S 


.00 


.016 


3 


94 


97-4 


.282 


-351 


14.84 


*i-4737 


2.28 


Mocha 


^ 


2-95 


3 


»5 


3-07 


.00 


.021 


3 


26 


84.7 


■2,33 


■ 364 


14-47 


*i-4743 


2.00 




^ 


2.40 


3 


80 


3.00 


.00 


.012 


3 


54 


93-3 


•337 


-545 


15.18 


*i-4740 


2.02 




A 


3-34 


4 


eg 


3-27 


.00 


.016 


3 


88 


95-0 


-^5« 


.421 


12.61 


1-4752 


2.48 


Java < 


^ 


3-35 


4 


3« 


3-56 


.00 


.019 


3 


54 


80.8 


.194 


.388 


12.28 


1-4758 


2-35 




c 


3-44 


3 


96 


3.10 


.00 


.011 


2 


95 


74-5 


•235 


■3>i3 


13-54 


1-4752 


2.56 


Highest.. 




3-44 


4 


3« 


3.62 


.CO 


.023 


4 


16 


102.3 


.424 


-545 


15.18 


1.4760 


2-56 


Lowest. . 




1.26 


3 


74 


3.00 


.00 


.011 


2 


■95 


71-4 


.194 


.166 


12.28 


1-4750 


2.00 


Average . 




2.16 


4 


03 


3.26 


.00 


.018 


3 


■55 


87.1 


.285 


-329 


13-75 


1-4754 


2.27 







<A 






6 






Ten Per Cent Extract. 






o' 


































Variety. 




T3 



u 

1 




0! 

60 

3 

M 

.E 

'0 
3 
•a 


s 

>s 




u 

0) 

T3 


6 
c 

(a 


Oi 
\~, 

ltd 


E c 

flj nJ 
e rt u 


Sg 


12 


J3 























c 














< 


* 


w 








Ol 






w 






fA 


20.80 


16.8s 


0.52 


2.28 


13-41 


1-25 


I. 0107 


26.7 


1-33770 


2.64 


0.40 


Santos 


B 


22.72 


17. II 


.68 


1. 00 


11.02 


1. 10 


I. 0108 


26.9 


1-33777 


2.66 


■39 




c 


21.70 


17.80 


■75 


2.32 


14-71 


1.20 


I.OIOI 


26.0 


1-33743 


2.46 


■30 


Porto • 
Rico 


t^B 


22.48 
21.76 


15-70 
16.36 


•50 
-63 


2.17 
1-58 


13. II 
12.93 


1-38 
1. 21 


I. 0107 
I. 0104 


26.6 
26.3 


1.33766 

1-33754 


2.60 
2.50 


-37 
.36 


c 


24.44 


16.91 


.54 


2.62 


12.50 


1.32 


I.OII3 


27.6 


1.33804 


2-77 


-30 




fA 


22.66 


17.00 


.68 


2.82 


14.08 


I. II 


I. 0103 


25-5 


1-33724 


2.48 


.40 


Rio 


B 


22.61 


17-34 


•78 


1-47 


13.10 


1. 10 


I.OIOI 


25-8 


1-33735 


2.46 


■3^ 




c 


22.75 


17-37 


.61 


2.62 


II. 91 


1. 17 


I.OIOI 


26.0 


1-33743 


2.46 


■30 




fA 


24.00 


18.01 


1.78 


2-30 


11.22 


1. 16 


I. 0106 


26.4 


1-33758 


2.65 


.40 


Mocha < 


B 


20.27 


17.96 


-94 


1-85 


12.34 


1. 10 


I.OIOI 


26.3 


1-33754 


2.47 


■3(> 




c 


24.18 


19-55 


1.42 


2.90 


13.20 


1. 18 


I.OIII 


27-3 


1-33793 


2.72 


.40 




[^ 


23-85 


15-95 


-32 


2.95 


13^43 


1-34 


I.OIIO 


29.6 


1.33777 


2.63 


•39 


Java 


B 


22.19 


15-45 


.42 


2-32 


13-77 


1.30 


I. 0107 


26.5 


1.33762 


2.58 


.38 




c 


23.20 


16.21 


.66 


3-34 


14-75 


1.27 


I. 0108 


26.6 


1.33766 


2.62 


.38 


Highest. . 




24.44 


19-55 


1.78 


3-34 


14-75 


1-34 


I.0II3 


27.6 


1.33804 


2-77 


.40 


Lowest. . 




20.27 


16.45 


•32 


1. 00 


11.02 


1. 10 


I.OIOI 


26.0 


1-33743 


2.46 


.30 


Average . 


... 


22.63 


17-03 


-75 


2.30 


13-03 


1.20 


I-OI05 


26.6 


1.33766 


2.72 


•37 



* Omitted from average. 



382 FOOD INSPECTION /1ND /1NALYSIS. 

COMPOSITION OF COFFEE SUBSTITUTES AND OF ADULTERATED COFFEE. 



Variety. 



Roasted wheat. 
Roasted chicory 
Coffee and 

chicory 

Coffee,chicory 

and pea hulls 



5.60 

5-55 

5.08 
3-64 



5-71 
4.37 

3-96 

4-97 



2.82 
2.27 



3-14 
4-05 



0.00 
.81 



.06 

-24 



0.080 

.026 

*.284 



Alkalinity 
(cc. N '10 
Acid) of 



0.341 6.0 
-95 

3-05 



1.8 

77.0 



2.60J 65.6 



0.649 

.277 

.286 
.472 



1 .460 
-314 

-323 
.740 



I" 



2.40 



^Z 

t*-, u 



9-56:1-4745 



!.I7 



Variety. 



Roasted wheat 
Roasted chicory 
Coffee and 

chicory 

Coffee, chicory 

and pea hulls 












ta 












X 


u 


W 


2 








X 




w 






^ 





•a 








.j^ 


U 


< 


25-88 


10.72 


72.92 


34-39 


31-79 


21.66 


25.00 


14-25 



4. 10 

19-34 
5.06 
3.00 



28.58 

2. 10 
2. 21 
3-78 



6.23 
5-91 

14-31 
17.87 



Ten Per Cent Extract. 



0.00 
.00, 1.0307 



-95 1-0142 

1 .00 



si"' 

.Sec 

d" O c^ 



45-0 1.34463 

30-5 :i-339i5 



7-44 
q.62 



0.26 
.29 



* Admixture of salt. 



METHODS OF ANALYSIS. 



The sample is prepared for analysis by grinding so as to pass a sieve 
with holes 0.5 mm. in diameter. 

Moisture, Ether Extract, Crude Fiber, Protein, and Ash (including 
total, water-soluble, water-insoluble, acid-insoluble and alkalinity) are 
determined as in the case of tea (pp. 368 and 369). Starch, Reducing 
Matters by Acid Conversion, Sucrose, and Reducing Sugars may be esti- 
mated by the methods described under cereal products. 

Ten Per Cent Extract. (See page 389.) 

Caffetannic Acid. — Krug's Method* — Two grams of the coffee are 
digested for thirty-six hours with 10 cc. of water, after which 25 cc. of 



* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 908. 



TEA, COFFEE, AND COCOA. 



2,^ 



90^[ alcohol are added, and the digestion continued for twenty-four 
hours more. The liquid is then filtered, and the residue washed with 
90% alcohol on the iilter. 

The filtrate, which contains tannin, caffeine, fat, etc., is heated to 
boiling and a boiling concentrated solution of acetate of lead is added, 
which precipitates out a caffetannate of lead, Pb3(Ci5Hi508)2, containing 
49% of lead. When this has become flocculent, it is separated by filtra- 
tion, and washed on the filter with 90% alcohol, till the washings show 



Mk 




Ek 




E7n 



II. 




Fig. 75. — Coffee. I. cross-section of berry, natural size. Pk outer pericarp; Mk endocarp; 
£^ spermoderm; ^a hard endosperm; 5/* soft endosperm. II. Longitudinal section of 
berry, natural size; Dis bordered disc; Se remains of sepals; Em embryo. III. Embryo 
enlarged; ro/ cotyledon; rad radicle. (Tschirch .and Oesterle.) 

no lead with ammonium sulphide, and afterwards with ether, till free 
from fat. It is dried at ioo° and weighed. 

The weight of caffetannic acid is obtained by multiplying the weight 
of the precipitate by 652, and dividing by 1263.63, 

Woodman and Taylor's Modification.'^ — To 2 grams of finely ground 
coffee (passing 0.5 mm. sieve), add 10 cc. of water, and shake for an 
hour in a mechanical shaking device. Add 25 cc. of 90% alcohol and 
shake again for half an hour. Filter and wash with 90% alcohol. Bring 
the united filtrate and washings, about 50 cc, to boiling, and add 6 cc. 
of saturated lead acetate solution. Separate the precipitated lead caffe- 
tannate by means of a centrifuge, decanting the supernatant liquid 
through a tared filter. Repeat the centrifugal treatment twice with 90% 
alcohol, decanting each time through the filter. Transfer the precipitate 
to the filter, and wash free from lead. Wash with ether, dry at ioo°, and 
weigh. The weight of the precipitate multiplied by 0.516 gives the weight 
of caffetannic acid. 



* A. O. A. C. Proc. 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 82. 



384 FOOD INSPECTION AND ANALYSIS. 

Caffeine. — Hilger and Fricke Method* — Boil from 5 to 10 grams of 
coffee with 100 cc. of water, filter, and treat the residue twice more with 
boiling water. Add to the united filtrates an excess of lead acetate, filter 
and wash. Pass hydrogen sulphide into the filtrate to remove the excess 
of lead, filter, wash and evaporate the filtrate to dryness in a Hoffmeister 
Schalchen with some sand and a little magnesia. Crush the Schalchen 
and extract with chloroform until exhausted. Dry the extract at 100° 
C. and weigh. If the caffeine does not appear to be pure, determine 
nitrogen in it by the Kjeldahl or Gunning method, multiply the amount 
of nitrogen by 3.464, thus obtaining the amount of pure caffeine. 

ADULTERATION OF COFFEE. 

According to the U. S. Standard roasted coffee is coffee which, by 
the action of heat, has become brown and developed its characteristic 
aroma, and contains not less than 10% of fat and not less than 3% of ash. 

Imitation Coffee. — Formerly, artificial coffee-beans containing no 
coffee whatever, but cleverly molded to imitate the original, were occa- 
sionally to be found, mixed with genuine, whole coffee. t 

" Coffee pellets " are occasionally sold in bulk to dealers as an adulter- 
ant of whole coffee. These do not closely resemble the real berries in 
appearance, but are approximately of the same size, and are not apparent 
to the purchaser when the whole coffee is ground at the time of purchase. 
A sample of these " pellets " examined recently was found to consist of 
roasted wheat mash, colored with red ocher. 

Coloring Coffee Beans. — The practice of treating raw coffee beans 
in a manner somewhat analogous to the facing of tea leaves has been 
sometimes practiced, with a view to giving to cheaper or inferior grades 
the appearance of high-priced coffee. For this purpose various pigments 
have been employed, such as yellow ocher, chrome yellow, burnt umber, 
Venetian red, Scheele's green, iron oxide, tumeric, indigo, Prussian 
blue, etc., the coffee beans being first moistened with water containing 
a little gum, and shaken with the pigment. As a rule such pigments, 
especially when inorganic, are best sought for either in the ash, or in the 
sediment obtained by shaking the coffee beans in cold water, using the 

* Arch. Pharm. 1885, p .827, U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 153 . 

t A sample of such imitation whole cofifee in the possession of the writer consists al- 
most entirely of roasted wheat molded into beans with difl&culty to be distinguished in 
appearance from those of genuine cofifee, so closely do they resemble the original, even to 
the cleft in the sides. The chaff in the cleft is, however, lacking. 



TEA, COFFEE, AND COCOA. 385 

ordinary qualitative chemical methods. Organic coloring matters can 
be best extracted with alcohol. Prussian blue and indigo are tested 
for as in the case of tea leaves (p. 375). 

Glazing. — This is a more recent form of treatment of the whole bean, 
which consists in coating the beans by dipping in egg or sugar, or a mix- 
ture of the two, sometimes using various gums. Such glazing is alleged 
to improve the keeping qualities of the coffee, as well as to aid in clarify- 
ing the infusion, and if this is the sole purpose, the practice cannot be 
condemned as a form of adulteration. If, however, it is done to give 
inferior varieties of coffee a better appearance, in order to deceive the 
consumer, it clearly constitutes adulteration within the meaning of the 
law. 

Adulterants of Ground Coffee. — Of the adulterants used in ground 
coffee the following have been found in Massachusetts: Roasted peas, 
beans, wheat, rye, oats, chicory, brown bread, pilot bread, charcoal, 
red slate, bark, and dried pellets, the latter consisting of ground peas, 
pea hulls, and cereals, held together with molasses. 

Methods of Detecting Adulterants. — These methods are, as a rule, 
physical rather than chemical. A rough test of the genuineness of ground 
coffee consists in shaking some of the sample in cold water. Pure coffee, 
under these conditions, usually floats on the surface, while the ordinary 
adulterants, such as cereals, chicory, mineral ingredients, etc., sink, 
ths grains of chicory coloring the water a brownish-red as they subside. 

Macfarlane recommends the use of a saturated solution of common 
salt, in which a portion of the suspected sample, divided in small grains, 
is shaken in a test-tube. If the liquid is colored pale amber, while all 
or nearly all the material floats, the coffee is pure. Any considerable 
sediment at the bottom of the tube, accompanied by a dark-yellow to 
brown color imparted to the liquid, indicates adulteration by roasted 
cereals, or chicory, or both. 

A careful examination of the coarsely crushed grains of a ground 
sample with the naked eye will often serve to detect, and in some cases 
identify, certain adulterants, such as chicory and ground peas or beans. 
A magnifying-glass will aid in such an examination, and the observer 
can often separate the various ingredients of a coffee mixture, first spread- 
ing a small portion of the sample on a sheet of white paper. The chicory 
grains are apparent from their dark and somewhat gummy appearance, 
and can usually be recognized by crushing them between the teeth. Their 
soft consistency and sweetish bitter taste are very distinctive. The dull 



386 FOOD INSPECTION AND ANALYSIS. 

outer surface of the crushed coffee grains is in marked contrast to the 
poHshed appearance of the surface of the broken peas or beans, often to 
be found as adukerants, while fragments of broken cereal grains are 
readily distinguished from coffee with a low-power magnifier, though 
perhaps not easily identified by the eye alone. 

Determination of Added Starch. — Starch is determined in the finely 
powdered sample as directed on page 283. 

Microscopical Examination of Coffee. — By far the best means of 
detecting adulteration is furnished by the microscope. The individual 
grains of coarsely ground coffee and adulterants, separated by the cold 
water test or by picking over the mixture, are identified by microscopic 
examination either after sectioning with a razor or crushing to a powder. 
In addition, examination is made of a small portion of the sample pulver- 
ized in a mortar to a degree fine enough to allow the cover-glass to lie 
fiat on the wetted powder, yet not so fine that it ceases to feel granular 
when rubbed between the fingers. The writer finds it sufiEicient to 
examine this powder in water without further treatment, although 
Schimper recommends maceration for twenty-four hours with ammonia, 
in order to render the tissues more transparent, using this reagent also 
as a mountant. 

In general the interior of the coffee tissue or endosperm consists of 
polygonal cells with highly characteristic, knotty, thickened walls, which 
are best seen in razor sections. Fig. 76, 2. These cells contain brilliant, 
colorless, spherical oil drops, and also proteins. 

The seed coat is also very characteristic, showing in the powder as 
occasional delicate silver-like patches, with peculiar, spindle-shaped, 
thick-sided cells, some of which are loosened from the tissue. 

Plates XIV and XV illustrate photomicrographs of pure and adulter- 
ated coffee. Fig. 174 shows genuine coffee, with its loose mesh of irreg- 
ularly polygonal cells, thick-walled, and inclosing oil drops with amor- 
phous material. It is not to be expected that every pulverized sample of 
genuine coffee, mounted as above, will show in every microscopic field the 
even, continuous structure that Fig. 174 illustrates, but careful examination 
will show in nearly every field fragments, and more or less disjointed por- 
tions of the polygonal cells, grouped in the form so characteristic of coffee. 
See Fig. 176. 

Chicory under the Microscope. — Fig. 77, after Moeller, shows struc- 
tural features of chicory. The most striking elements are the fine, thick- 
walled, long-celled, parenchyma of the bark rp and hp with its delicate 



TE/I, COFFEE, /fND COCOA. 



387 








Fig. 75. — -Powdered Coffee under the Microscope. X125. (After Moeller.) i, seed 
coat (surface). 2, endosperm parenchyma. 




r 'r 




-qn '>!> 




Fig. 77. — Chicory Root in Tangential and Radial Sections. X160. g, reticulated ducts 
with perforations qu; hp, wood parenchyma; /, wood fibers; rp, bark parenchyma; 
sch, milk ducts; bp, bast parenchyma; m, medullan,- rays. (After Moeller.) 



388 FOOD INSPECTION AND ANALYSIS. 

tracery, and the vcss-ls or ducts g of the wood tibers. These ducts are 
tubular, resembhng jointed cylinders, often with overlapping joints. 
Less distinct, but very characteristic of certain roots of the composite 
family, are the narrower branching milk ducts sch which do not exist 
in beets, turnips, and other roots sometimes substituted for chicory. 

Fig. 178, PI. XV, is a photomicrograph of an aduherated sample of 
coffee, showing in this particular field chicory alone. It is a mass of con- 
fused cellular tissue, traversed by two broad bands of the vessels, with 
their striking, transverse, dotted markings. 

Fig. 177, PI. XV, shows a sample of coffee adulterated with roasted 
peas and pea hulls. No genuine coffee appears in this field. The chief 
masses in the center are characteristic aggregations of the round starch 
granules of the roasted pea. The rectangular billets, like bunches of 
matches, are from the outer or palisade layer of the pea. 

Fig. 164, PI. XI, and Fig. 154, PI. IX, show the close resemblance 
between the starches of the pea and bean, both of which are commonly 
used in coffee. 

The palisade structures of the hulls of these legumes also bear a close 
resemblance, but the cells of the next layer in the pea are hour-glass 
shaped, while in the bean they are not remarkable for their shape, but for 
the single crystal of calcium oxalate contained in each. 

The effect of roasting on starches used as adulterants of coffee is to 
twist and distort the granules, in some cases destroying largely the even 
structure of the raw starch. Starch granules of wheat, barley, and rye, 
for example, are almost perfect circular disks in the case of the raw starch, 
while in roasted products, such as pilot biscuit and stale bread, the 
granules are twisted and distorted, sometimes almost forming the letter 
" S." 

Use of Chicory in Coffee. — Chicory is a perennial herb {Cicorium 
intyhus) of the same family (CompositcE) as the dandelion. The roasted 
and pulverized chicory root is so much used in ground coffee to impart 
a peculiar flavor thereto, that by many it is considered as not strictly 
an adulterant. The taste imparted to coffee by a small admixture of 
pure chicory is to some desirable, but if its unrestricted use is sanctioned 
in this manner, the door would soon be opened to a more unlimited form 
of adulteration, wherein the chicory might predominate. It is, therefore, 
best to regard chicory as an adulterant, and to require the package con- 
taining a mixture of coffee and chicory, if sold legally, to have plainly 
printed thereon the percentage of chicory in the mixture. 



TEA, COFFEE, AND COCOA. 389 

Chicory, when roasted, consists of gum, partly caramelized sugar, 
and insoluble vegetable tissue. Common adulterants of chicory are 
dried beets and other roots, also cereal matter. 

Villiers and Collin * give the following analyses of two samples of 
chicorv : 



In Large 
Granules. 



In Powder. 



Soluble in water: 



Insoluble in water: 



Water (loss at 100° to 103°) 

Weight of total matter soluble in water. 

Reducing sugar 

■ Dextrin, gum, inulin 

Albuminoids 

Mineral matter 

. Coloring matter 

r .Albuminoids 

I Weight of the total insoluble matter. . . . 

Mineral matter 

Fat 

[ Cellulose 



16.28 
57-96 
26. 12 

9-63 

3-23 

2.58 

16.40 

3-15 
25.76 

4.58 

5-71 

12.32 



16.96 

56.90 

23-79 

9-31 

3-66 

2-55 
17-59 

2.98 
26. 14 

5-87 

3-92 
13-37 



See also analysis of roasted chicory on page 382. 

Detection and Estimation of Chicory. — Various chemical tests for 
detection of chicor\' in coffee infusions have been suggested, depending on 
color reactions, t but these are, as a rule, unreliable. By far the best 
means for detecting chicory in coffee is furnished by the microscope. 

In mixtures containing coffee and chicory only, the approximate amount 
of the latter can be calculated from the specific gravity of a 10% decoc- 
tion, using conveniently the method of McGill.| A quantity of the pul- 
verized sample, corresponding to 10 grams of the dr)' sub.stance, is weighed 
in a counterbalanced ilask, and water added till the weight of the contents 
is no grams. Fit the flask with a reflux condenser, and after so regulat- 
ing the heat that boiling begins in ten to fifteen minutes, continue the 
boiling for an hour. Remove the flame, and after fifteen minutes pass 
through a dry filter, cool, and determine the specific gravity at 15°. 
McGill found the average specific gravity of a 10% decoction as above 
carried out to be, in the case of pure coffee, 1.00986 and in the case of 
chicor}' 1.02821, the difference being 0.01835. 

The specific gravity of the 10% decoction of the suspected sample 

* Falsifications et .Alterations des Substances .A limentaires, p. 234. 
t See Allen's Commercial Org. Analysis, Vol. Ill, pt. II, p. 540. 
I Trans. Royal Soc. of Canada, 1887. 



39° 



FOOD INSPECTION AND ANALYSIS. 



at 15° being d, the per cent of chicor)^, c, can be calculated roughly by 

the formula 

(1.02821— (/)lOO 



c=ioo- 



0.01835 



This method is of course inapplicable when other substances than 
chicor}^ are present. 

Date Stones, roasted and ground, have been used to some extent as a 
coffee adulterant. Fig. 78 shows the structural features of date stones 




Fig. 78. — ^Powdered Date Stones under the Microscope, end, endocarp; e, episperm; 
a, albumen in cross-section; a', albumen in longitudinal section. (After Villiers and 
Collin.) 

under the microscope. End represents a fragment of endocarp with its 
elongated, thick-walled cells, peculiarly arranged as shown, adjacent cells 
often lying with axes at right angles to each other. The more evenly 
formed episperm cells, e, arc thin-walled and of a brown color. The 
albumen, a, is made up of very thick-walled, somewhat regularly arranged 
cells, indented from within with deep channels. Date stones are readily 
distinguished from coffee by these features. 

Hygienic Coffee. — Various processes have been devised for removing 
the caffeine from coffee. One of these, patented in Germany, has recently 
come into extensive use, as the flavor of the beverage is not greatly injured 
by the treatment. In following out this process the whole beans are first 
exhausted with water in a vacuum, and the infusion extracted with a 
suitable solvent for caffeine. The exhausted beans are then impregnated 
with the decaffeinated infusion and dried in a vacuum. This treatment, 



TEA, CGFEEE, AND COCOA. 



391 



as shown by the investigations of Lendrich and Murdfield * does not 
completely remove all the caffeine, the quantity remaining being from 
0.14 to 0.26%, or about one-sixth of that in the untreated coft'ee. Further 
effects of the treatment are a decrease in the water extract and an increase 
in the fat. The following are the average of analyses, made by these 
authors, of caffeine-free and untreated coffee: 









Analysis of the Dry Substance. 






a 


IkI. 




el 


u 
1 d) 


'So 




< 






XI 


2 


3 u 


s£ 


oX 






t 




3 
r1 


« ^a 

■-2: oic 




l« 


01 * 








3 


X 


^4 


kalin 
(cc. 
per I 
of Cc 


u 


^■5 
15^ 




.5 2 
oS5 




^ 


S 


< 


is 


< 


^ 


fe 


u 


a, 






% 


% 


% 




% 


% 


% 


% 


"Caffeine-free Coffee". .. 


14 


2.13 


4-23 


3.22 


47-72 


21.30 


17-13 


0. 22 


ri.83 


Untreated coffee 


9 


1.46 


4.71 


3-77 


56.43 


26.17 


15-73 


I. 19 


11-75 



Several brands of coffee, advertised to be free from tannin and in 
some cases also from caffeine, have been placed on the market in the 
United States. Some of these consist merely of ground coffee from 
which the chaff (which is represented to contain not only the tannin but 
also most of the caffeine) has been removed by mechancial means. The 
absurdity of the claims of the manufacturers is shown by the following 
analyses made in New Hampshire by C. D. Howard. f 



Water. 


Ash. 


Fat. 


Fiber. 


Caffeine. 


2.70 


4. 10 


13. iG 


18.46 


1. 17 


2.70 


4-05 


14.12 


15-70 


I- 3 


2.26 


3.61 


12-55 


22.70 


0.87 


3-13 


4-13 


14.10 


15-50 


1.29 


2.60 


5.65 


9-30 


26.50 


0.40 



Caffe- 
tannic 
Acid. 



Tanninless coffee No. i 
Tanninless coffee No. 2 
Tanninless coffee No. 3 

Java and Mocha 

Coffee chaff 



10.76 
II .04 

7.61 
II .17 

5-98 



The following analyses made at the Connecticut Station by E. J. 
ShanlevJ corroborate those of Howard : 



* Zeits. Unters. Nahr. Genuss., 15, 1908, p. 705. 

t A. O. A. C. Proc. 1906, U. S. Dept. of Agric, Bur. of Chem., Bui. 105, p. 41. 

X An. Rep. Conn. Exp. Sta., 1907, p. 141. 



392 



FOOD INSPECTION AND ANALYSIS. 



Caffeine in the 
Coffee. 



Caffetannic 

Acid in the 

Coffee. 



Caffetannic 

Acid in the 

Chaff. 



Per Cent of 

Chaff in the 

Coffee. 



Tanninless coffee A. 
Tanninless coffee B. 
Tanninless coffee C. 

Java coffee 

Mocha coffee 

Rio coffee 



1. 14 

1. 11 

1. 12 

1.26 
1-13 



9.89 

9-45 
9.96 

9-51 
9.96 

9-47 



5-46 

7-55 
6-79 



1.80 
2.38 
1-77 



Coffee Substitutes. — A large number of preparations sold as " coffee 
substitutes " or " cereal coffee " are now on the market in the United 
States, most of which are composed, as alleged on the labels, of cereals, 
ground peas, etc. Some contain roasted wheat, malt or some other 
cereal alme, others are mixtures of cereals or cereal products and peas, 
and a few contain chicory. Some of these preparations have labels 
calling attention to the evil effects of coffee, and one of the latter class, 
extensively advertised, .ind purporting to contain nothing but the entire 
wheat kernel roasted and ground, was found to contain peas, and about 
30% of that " most harmful ingredient " coffee itself. Various substitutes 
are also made from dried fruits such as figs, prunes and bananas. 

In addition to the materials named the following have been used in 
Europe: beans, lupine seeds, cassia seeds, astragalus seeds, Parkia seeds, 
chick peas, soja beans, dried pears, carob bean pods, date stones, ivory 
nuts, acorns, grape seeds, fruit of the wax palm, cola nuts, false flaxseed, 
dandelion roots, beets, turnips and carrots.* 

As in the case of coffee the analyst must depend chiefly on the micro- 
scope in identifying the constituents of coffee substitutes. Coffee itself 
should properly be considered in the light of an adulterant. 

COCOA AND COCOA PRODUCTS. 

Nature of the Cocoa Bean. — The various chocolate and cocoa 
preparations are made from the bean of the tree Thcohroma cacao, of the 
family of ByttneriacecE . This tree averages 13 feet in height, and its main 
trunk is from 5 to 8 inches in diameter. It is a native of the American 
tropics, being especially abundant and growing under best conditions in 
Mexico, Central America, Brazil, and the West Indies. 

The cocoa beans of commerce are derived chiefly from Ariba, Bahia, 
Caracas, Cayenne, Ceylon, Guatemala, Haiti, Java, Machala, Mara- 



* Winton's Microscopy of Foods, p. 435. 



TEA, COFFEE, AND COCOA. 393 

caibo, St. Domingo, Surinam, and Trinidad. Besides these, the Sey- 
chelles and Martinique furnish a small amount. 

The plant seeds, or beans, grow in pods, varying in length from 23 to 
30 cm., and are from 10 to 15 cm. in diameter. The beans, which are 
about the size of almonds, are closely packed together in the pod. 
Their color when fresh is white, but they turn brown on drying. 

The gathered pods are first cut open, and the seeds removed to undergo 
the process of " sweating " or fermenting, which is carried out either 
in boxes or in holes made in the ground. This process requires great 
care and attention, as upon it depends largely the flavor of the seed. 
The sweating operation usually takes two days, after which the seeds 
are dried in the sun till they assume their characteristic warm red color, 
and in this form are shipped into our markets. 

Manufacture of Chocolate and Cocoa. — For the production of 
chocolate and cocoa the beans are cleaned and carefully roasted, during 
which process the flavor is more carefully developed, and the thin, paper- 
like shell which surrounds the seed is loosened, and is very readily 
removed. The roasted seeds are crushed, and the shells, which are 
separated by winnowing, form a low-priced product, from which an 
infusion may be made, having a taste and flavor much resembling chocolate. 

The crushed fragments of the kernel or seed proper are called cocoa 
nibs, and for the preparation of chocolate they are finely ground into 
a paste and run into molds, either directly, or after being mixed with 
sugar and vanilla extract or spices, according to whether plain or sweet 
chocolate is the end product. 

For making cocoa, however, a portion of the oil or fat known as the 
cocoa butter is first removed, by subjecting the ground seed fragments 
to hydraulic pressure, usually between heated plates, after which the 
pressed mass is reduced to a very fine powder, either directly, or by treat- 
ment with ammonia or alkalies, to render the product more soluble. It 
is held that the large amount of fat contained in the cocoa seeds (vary- 
ing from 40 to 54 per cent) is difficult of digestion to many, such as invalids 
and children, and hence the desirability of removing part of the fat. 

Composition of Cocoa Products. — The chief constituents of the 
raw cocoa bean, named in the order of their relative amount, are fat, 
protein, starch, water, crude fiber, ash, theobromine, gum, and tannin. 
During the roasting there is reason to believe a volatile substance is 
developed much in the nature of an essential oil, which gives to the 



394 



FOOD INSPECTION AND ANALYSIS. 



product its peculiar flavor, and is somewhat analogous to the caffeol of 
coffee. 

Tannin, the astringent principle of cocoa, exists as such in the raw 
bean, but rapidly becomes oxidized to form cocoa red, to which the color 
of cocoa is due. 

Weigmann gives the following results of analyses of cocoa nibs and 
shells : 

COMPOSITION OF COCOA NIBS. 



Commercial Varieties. 



3 o m6 

5? M ^! O 



u >> 

.Co 



Caracas 

Trinidad 

Surinam 

Port au Prince. 

Machata 

Puerto Cabello 
Ariba 



7-77 
7.87 

7-53 
7-77 
8.17 
8.08 
8.27 



14 


13 


14 


06 


13 


69 


14 





14 


06 


13 


50 


15 


37 



1.48 
I-3I 

1.66 



45-54 
44.62 

44-74 
46.35 
45-93 
46.61 

45-15 



.40 
-30 
-45 
-97 
.69 

-9 
■83 



15-53 
17-50 

16.96 



6.19 
4-55 
4-30 
5-19 
4.36 
4-43 
4-48 



4.91 
3- 



,16 



2.06 

o.io 

0-13 
1.48 
0.22 
0.18 
0.14 



COMPOSITION OF COCOA SHELLS. 









6 




0) 








h 




<0 


" 


6 




cri 


oj 








Commercial Varieties. 


^ 




£ 








_o 
■3 




•d 








is :3 










X. 


c 


■K ^ 




s 


g^ 


J3 




gw 




< 




^« 


Caracas 


12.49 
14.64 

13-93 
14.89 


13.18 
14.62 
16.25 
16.18 


0.58 
0.74 
0.78 

0.75 


2.38 

3-45 
2.54 
2.01 


40.30 
44.89 
42.47 
43-32 


16.33 
15-79 
17.04 

15-25 


9.06 
6.19 

6-63 

8.08 


6.26 


2. II 


Trinidad 


0.42 


2-34 
2.60 


Surinam 


0.85 
0.27 


Puerto Cabello 


2-59 





The following are the summarized results of the analyses of seventeen 
varieties of cocoa seeds and shells, made by Winton, Silverman, and 
Bailey.* 



* An. Rep. Conn. Agric. Exp. Sta., 1902, p. 270. 



TEA, COFFEE, AND COCOA. 



3.5 



W'ater 

Total ash , 

Water-soluble ash 

Ash insoluble in acid 

Alkalinity of ash 

Theobromine 

Caffeine 

Other nitrogenous substances 

Crude fiber 

Crude starch (acid conversion) 

Pure starch (diastase conversion) 

Other nitrogen-free substances 

Fat 

Total nitrogen 

Constants of fat (ether extract) : 

Melting-point, degrees C 

Zeiss refractometer reading at 40° C 

Refractive index at 40° C 

Iodine number 

Per cent of nibs in whole bean 

" " "shells " " " 



Roasted Cocoa Nibs. 



Air-drv Material. 



Maxi- 
mum. 



Mini- 
mum. 



3.18 

4-15 
1.86 
0.07 

3-35 
1 .32 

0-73 
13.06 

3.20 
12.37 

8-99 
21.07 

52-25 
2-54 

35-0 
48.0c 

-4579 
37-89 
92.90 
13.88 



-29 
.61 

-73 
.00 
.50 
.82 
.14 
.00 



32-3 
46.00 

[-4565 

33-74 

86.12 

8.83 



Mean. 



2.72 
3-32 
1. 16 
0.02 

2-51 
1.04 
0.40 

12.12 
2.64 

II. 16 
8.07 

19-57 

50.12 

2.38 

47-23 
-4573 
34-97 
88.46 

ir-54 



Water- and Fat-free 
Material. 



Maxi- 
mum. 



8.81 
3-96 
0.14 
7.12 
2.92 

1-55 
28.05 

6.56 
25.68 
18.61 
44.08 

5-41 



Mini- 
mum. 



5-76 
1.60 
0.00 

3-29 
1.66 
0.31 

23-37 
4.70 
19.80 
13.82 
38-78 

4-74 



Mean. 



7.04 

2.46 

0.05 

5-32 

2.21 

0.86 

25.69 

5.61 

23.66 

17.10 

41.49 

5-05 



Water 

Total ash 

Water-soluble ash 

Ash insoluble in acid 

Alkalinity of ash 

Theobromine 

Caffeine 

Other nitrogenous substances 

Crude fiber 

Crude starch (acid conversion). . 
Pure starch (diastase conversion) 
Other nitrogen-free substances. . 

Fat 

Total nitrogen 



Roasted Cocoa Shells. 



Air-dry Material. 



Maxi- 
mum. 



^-57 
20.72 

5-67 
II. 18 

5-92 

0.90 

0.28 

18.06 

19.21 

13.89 

5.16 

51.86 

5-23 

3-17 



Mini- 
mum. 



■71 
.14 
.02 

-05 
.02 
.20 
.04 
.69 

-93 

.87 

-36 

-71 
.66 

•74 



Mean. 



Water- and Fat-free 
Material. 



Maxi- 
mum. 



4.87 
10.48 
3-67 
2-51 
5-52 
0.49 
0.16 

14.54 
16.63 
11.62 
4.14 
46.40 

2-77 
2.34 



21.97 

6. II 

11.86 

6-47 

0.97 

0.31 

19.40 

20.72 

15-42 

5-59 

55-84 

3-41 



Mini- 


Mean. 


mum. 




5-63 


^^•Z3 


2.16 


3-97 


0.05 


2.70 


5-32 


5-97 


0.22 


0.52 


0.04 


0.17 


11-34 


15-70 


13-71 


18.01 


10.47 


12-59 


3-65 


4-47 


47.04 


50.08 


1.87 


2.54 



396 FOOD INSPECTION AND ANALYSIS. 

According to Bell* the ash of cocoa nibs has the following composi- 
tion: 

Per Cent. 

Sodium chloride 0.57 

Soda 0-57 

Potash 27 . 64 

Magnesia 19.81 

Lime. 4-53 

Alumina 0.08 

Ferric oxide 0.15 

Carbonic acid 2.92 

Sulphuric acid 4.53 

Phosphoric acid 39 - 20 



100.00 



Theobromine (C^HgN^Oj), the chief alkaloid of cocoa, when pure, 
forms a white, crystalline powder, having a bitter taste. It is slightly- 
soluble in water and alcohol, very slightly soluble in ether, insoluble 
in petroleum ether, but readily soluble in chloroform. It sublimes at 
290° to 295° C. It is a weak base, and much resembles caffeine. A small 
amount of caffeine has also been found in cocoa, but in most analyses 
is reckoned in with the theobromine. 

The Nitrogenous Substances of Cocoa, aside from the alkaloids, have 
been little studied. Stutzer has, however, separated them roughly as 
in the following analyses of four samples, of which A was manufactured 
without chemicals, B with potash, and C and D with ammonia: 



c. 



D. 



Total nitrogen 

Theobromine 

Ammonia 

Amido compounds 

Digestible albumin 

Indigestible nitrogenous substances 

Containing nitrogen 

Proportion of total nitrogen indigestible . 



3. 68 
1.92 
0.06 

1-43 

10.2^ 

7.18 

1-15 
31.2 



3-95 
1.98 
0.46 
0.31 

10.50 
7.68 
1.23 

31.2 



3-57 
1.80 

0-33 
1-31 
7.81 
8.00 
1.28 
35-8 



Pentosans. — Several authors have called attention to the value of 

these substances as a means of detecting added shells in cocoa products. 

Liihrig and Seginf found in cocoa nibs from 2.51 to 4.58 per cent 



* Analysis and Adulteration of Foods. 

t Zeits. Unters. Nahr. Genuss., 12, 1906, p. i6r. 



TEA, COFFEE, AND COCOA. 



397 



of pentosans calculated to the dry, fat-free substance, and in the shells 
from 7.59 to 11.23 per cent calculated to the dry substance. 

Milk Chocolate, a product of comparatively recent introduction, 
consists of a mixture of chocolate, sugar, milk powder, and cocoa butter. 
It is especially prized by travelers and others who desire a concentrated, 
and at the same time palatable food. 

The following analyses by Dubois * show the composition of three 
of the leading brands on the market, and also illustrate the accuracy of 
Dubois' method of determining sucrose and lactose given on page 399. 



Polarization, 



Direct. 



After 
Inver- 
sion. 



Temp. 
°C. 



At 86° 



Su- 
crose, 

Per 
Cent. 



Lac- 
tose, 
Per 
Cent. 



Reich- 

ert- 
Meissl 
Num- 
ber of 
Fat. 



Approx. 

Per Cent 

Butter 

Fat in 

Total 

Fat. 



Commercial milk chocolate: 

A 

B 

C 

Milk chocolate made in the 
laboratory: 

•pj / Found 

1 Calculated 

y. j Found 

\ Calculated 



+ 21 .00 
+ 23.22 
+ 2,;. 88 



+ 19.00 



24 



+ 19.70 



1-50 
2.20 



+ 1.36 
+ 1 . 50 
+ 1.36 



+ 1.40 



+ 0.99 



40.90 

45-73 
46.78 



35-99 
35-82 
39-84 
39.80 



S.24 
9. 12 
8.24 



8.52 
8.82 
6.03 
5-88 



5-3 
5-5 
5-8 



4-83 
3-48 



22.9 
24.2 



14-5 



Various Compounds of chocolate or cocoa with other materials have 
been placed on the market. Zippcrer "f gives formulas or analyses of 
seventy-four such preparations, containing one or more of the following 
ingredients: oatmeal, barley meal, malt, malt extract, wheat flour, potato 
flour, rice, peas, peanuts, acorns, cola nuts, sago, arrowroot, Iceland 
moss, gum Arabic, salep, dried meat, meat extract, peptones, milk powder, 
plasmon (a preparation of casein), eggs, saccharin, vanilla, spices, and 
inorganic salts. Certain medicinal preparations also contain cocoa 
products. 

Cocoa Butter. — See page 529. 



* Jour. Am. Chem. Soc, 29, 1907, p. 556. 

t The Manufacture of Chocolate and Cacao Preparations, 2d ed., 1902. 



39« 



FOOD INSPECTION /1ND ANALYSIS. 



METHODS OF ANALYSES. 

Preparation of the Sample. — Cocoa is usually in a fine powder, 
and needs merely to be put through a sieve, to break up lumps, and mixed. 
Chocolate should be grated or shaved so as to permit mixing. It can 
not be ground, as the heat of grinding reduces it to a paste. 

Moisture. — Dry two grams of the material to constant weight at ioo° 
C. in a current of dry hydrogen. Somewhat lower results are obtained 
by drying in a dish in air. 

Ash. — Proceed as described under tea (page 369) in the determination 
of total, water-soluble and acid-soluble ash, and the alkalinity of the ash. 




Fig. 79. — Cocoa. 7 entire fruit, X^; II fruit in cross-section; III seed (cocoa bean) 
natural size; IV seed deprived of seed coat; V seed in longitudinal section, showing 
radicle (germ) ; VI seed in cross-section. (Winton.) 

Protein, — Determine total nitrogen by the Kjeldahl or Gunning 
method. From the percentage of total nitrogen subtract the nitrogen 
of the theobromin and caffeine, obtained by multiplying the percentages 
found by 0.31 1 and 0.289 respectively, and multiply the remainder by 
6.25. 

Fat (Ether Extract). — Extract two grams of the material in a con- 
tinuous extractor until no more fat is removed. Grind the residue and 
repeat the extraction. Dry the combined extract at 100° C. and weigh. 

Constants of Fat.— See chapter on Edible Oils and Fats. 

Crude Fiber. — Proceed as in the analysis of cereal products (page 
277), using the residue from the ether extraction. 



TEA, COFFEE AND COCOA. 399 

Reducing Matters by Acid Conversion (Crude Starch).* — Weigh 
four grams of the material into a small Wedgewood mortar, add 25 cc. of 
ether, and grind with a pestle. After the coarser material has settled 
out, decant off the ether with the line suspended matter on a 11 cm. paper. 
Repeat this treatment until no more coarse material remains. After the 
ether has evaporated, transfer the fat-free residue from the filter to the 
mortar by means of a jet of cold water, and rub to an even paste. Filter 
the liquid on the paper previously employed. Repeat the process of 
transferring from the filter to the mortar, grinding, and filtering, until 
all sugar is removed. In the case of sweetened cocoa products, at least 
500 cc. of water should be iLsed. 

Transfer the residue to a 500-cc. flask by means of 200 cc. of water, 
and convert the starch into dextrose by Sachsse's method (page 283). 

Cool the acid solution, nearly neutralize with sodium hydroxide solu- 
tion, add 5 cc. of lead sub-acetate solution (page 586), make up to 250 
cc. and filter through a dry filter. To 100 cc. of the filtrate, add i cc. 
of 60% sulphuric acid, shake thoroughly, allow to settle, and filter through 
a dry filter. 

Determine reducing matters by AUihn's method (page 608). 

Dubois,'\ instead of treating with ether as above described, shakes four 
grams of the unsweetened product or eight grams of the sweetened with 
100 cc, of gasoline, and whirls in a centrifuge to separate from the insoluble 
matter. After decanting off the gasoline layer, sweetened products are 
treated in like manner with two portions of 100 cc. of water to remove 
the bulk of the sugar, and finally washed on the paper. 

Starch. — Diastase Method. — Remove the fat and sugar from four grams 
of the material by treatment with ether and water, as described in the 
preceeding section, and determine starch in the residue by the diastase 
method (page 283). 

Pentosans. See page 285, 

Sucrose and Lactose, — Dubois's Method.X — Extract the fat from 13 
grams of the sample by shaking and centrifuging twice with 100 cc. of 
gasoline, separating the solvent by decantation. To the residue add 100 
cc. of water, and shake for ten minutes. Add 5 cc. of basic lead acetate 
solution (p. 586), filter, and remove the excess of lead. Allow 25 cc. of 
this solution to stand over night to destroy birotation, and polarize, Mul- 

* Winton, Silverman and Bailey, An. Rep. Conn. Exp. Sta., 1902, p. 275. 

t A. O. A. C. Proc. 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 214. 

X Jour. Am. Chem. Soc, 29, 1907, p. 556. 



400 FOOD INSPECTION AND ANALYSIS. 

tiply readings by 2. Invert 50 cc. of the above filtrate as described on 
page 588, nearly neutralizing the acid after cooling with sodium hydroxide 
solution, and make up to 100 cc. Bring to temperature at which direct 
readings were made and polarize, and also polarize at 86° in a water 
jacketed tube; multiply all invert readings by 4. 

Calculate the approximate weight of sucrose and lactose present in 
the 13 grams by the following formulas: 

{a-b)i.os 
Grams of sucrose = Xi^. 

142.66 — 
2 

cXi. 264X1. II X1.05X13 19.152c 

Grams of lactose = = . 

100 100 

a=direct readings, normal weight. 
6 = invert readings, normal weight. 
c = invert readings, normal weight, at 86° C. 
From the total amount of sugar found by the above, obtam the value 
of X from the table below, and calculate sugars as follows: 

{a — h)i.o^x 

=per cent of sucrose. (i.473c):x: = per cent of lactose. 

142.66 — 

2 

2 grams of sugar in sample, :x; = 101.2 

4 grams of sugar in sample, :v = 102.5 

6 grams of sugar in sample, .v = 103.6 

8 grams of sugar in sample, x = 104.8 
10 grams of sugar in sample, x* = 106.05 
15 grams of sugar in sample, x = 109.40 
20 grams of sugar in sample, x = 112.40 

Theobromine and Caffeine {Decker-Kunze Method).'^ — Boil 10 grams 
of the powdered material and 5 grams of calcined magnesia for 30 
minutes with 300 cc. of water. Filter by the aid of suction on a Buchner 
funnel, using a round disk of filter paper. Transfer the material and 
paper to the same flask used for the first boiling, add 150 cc. of water, 

* Schweiz. Wchschr. Phar., 40, 1902, pp. 527, 541, 553; Abstract Chem. Centr., 74, 1903, 
p. 62; An. Rep. Conn. Exp. Sta., 1902, p. 274. 



TEA, COFFEE, AND COCOA. 4CI 

and boil 15 minutes. Filter as before, and repeat the operation of boiling 
with 150 cc. of water and filtering. Wash once or twice with hot water. 
Evaporate the united filtrates (with quartz sand if sugar be present) 
to complete dryness in a thin glass dish of about 300 cc. capacity.* 

Grind to a coarse powder in a mortar provided with a suitable cover 
to prevent loss by flying. Transfer to the inner tube of a continuous 
fat extractor, and dry thoroughly in a water oven. Extract with chloro- 
form for 8 hours, or until the theobromine and caft'eine are completely 
removed, into a weighed flask. It is important that the material be 
thoroughly dry, that an extractor be used that permits of a hot extraction, 
and that a considerable volume of chloroform passes through the material. 
Distil off the chloroform, and dry at 100° C. to constant weight. 
'' If the material be pure chocolate or cocoa, the extract thus obtained 
is practically pure theobromine and caffeine, but if the material is cocoa 
shells or a cocoa product mixed with a large amount of shells, the extract 
may be brown in color, due to the presence of considerable amounts of 
impurities. 

In either case, separate the caffeine by treating the extract in the flask 
at the room temperature for some hours with 50 cc. of pure benzol. 
Filter through a small paper into a tared dish, evaporate to dryness, and 
dry to constant weight at 100° C, thus obtaining the amount of caffeine. 

Determine theobromine by Kunze'sf method, as follows: 

Add to the residue and paper 150 cc. of water, enough ammonia water 
to make the liquid slightly alkaline, and an excess of decinormal silver 
nitrate solution. Boil to half the original volume, add 75 cc. of water, 
and repeat the boiling. The solution should be perfectly neutral. If it 
contains the slightest amount of free ammonia, add water and boil until 
it is completely removed. 

Filter from the insoluble silver theobromine compound, and wash with 
hot water. In the filtrate determine the excess of silver nitrate by 
Volhard'sJ method as follows: 

Add 5 cc. of cold saturated solution of ferric ammonium sulphate 
(ferric-ammonium alum), and enough boiled nitric acid to bleach the 
liquid. Titrate with decinormal ammonium sulphocyanide solution 
until a permanent red color appears. 

* A " Hoffmeister Schalchen " may be used, or dishes may be made from broken flasks 
by making a scratch with a diamond and leading a crack from this scratch about the flask 
by means of a glowing springcoal. 

fZtschr f. anal. Chem., t,t„ 1894, p. i. 

X Ibid., 13, 1874, p. 171. 



402 FOOD INSPECTION ^ND ANALYSIS. 

One cc. of decinormal AgNOa solution is equivalent to 0.01802 gram 
of theobromine. If the mixed alkaloids were colorless, the theobromine 
obtained by subtracting the weight of caffeine from the weight of the 
mixed alkaloids will usually agree closely with that obtained by silver 
titration. 

ADULTERATION OF COCOA PRODUCTS AND STANDARDS OF PURITY, 

The following are the U. S. standards:* Standard chocolate should 
contain not more than 3% of ash insoluble in water, 3.5% of crude fiber, 
and 9% of starch, nor less than 45% of cocoa fat. 

Standard sweet chocolate and standard chocolate coating are plain 
chocolate mixed with sugar (sucrose), with or without the addition of 
cocoa butter, spices, or other flavoring material, containing in the sugar- 
and fat-free residue no higher percentage of either ash, fiber, or starcti 
than is found in the sugar- and fat-free residue of plain chocolate. 

Standard cocoa should contain percentages of ash, crude fiber, and 
starch corresponding to those of plain chocolate, after correcting for fat 
removed. 

Standard sweet cocoa is cocoa mixed with sugar (sucrose) containing 
not more than 60% of sugar, and in the sugar- and fat-free residue no 
higher percentage of either ash, crude fiber, or starch than is found in 
ihe sugar- and fat-free residue of plain chocolate. 

The removal of fat, or the addition of sugar beyond the above pre- 
scribed limits, or the addition of foreign fats, foreign starches, or other 
foreign substances, constitutes adulteration, unless plainly stated on the 
label. 

The most common adulterants of cocoa are sugar and various starches, 
especially those of wheat, com, and arrowroot. Starch is sometimes 
added for the alleged purpose of diluting the cocoa fat, instead of remov- 
ing the latter by pressure, thus, it is claimed, rendering the cocoa more 
digestible and more nutritious. Unless its presence is announced on 
the label of i-he package, starch should be considered as an adulterant. 
Cocoa shells are also commonly employed as a substitute for, or an 
adulterant of, cocoa. Other foreign substances found in cocoa are sand 
and ground wood fiber of various kinds. Iron oxide is occasionally 
used as a coloring matter, especially in cheap varieties. 

* U. S. Dept. of Agric, Off. of Sec, Circ. 19. 



TE/I, COFFEE. AND COCOA 403 

Such adulterants as the starches and cocoa shells are best detected by 
the microscope. The presence of any considerable admixture of sugar 
is made apparent by the taste. Mineral adulterants are sought for in 
the ash. 

Addition of Alkali. — The amount of water-soluble matter in cocoa 
is very small (about 20 to 25 per cent), and in preparing the beverage, 
the desideratum aimed at is to produce as perfect an emulsion as possible. 
The legitimate means of accompHshing this is by pulverizing the cocoa 
very fine, so that particles remain in even suspension and form a smooth 
paste. Another means sometimes resorted to for producing a so-called 
"soluble cocoa" is to add alkah in its manufacture, the effect being to 
act upon a part of the fat, and produce a more perfect emulsion with less 
separation of oil particles. Such treatment with alkah is regarded with 
disfavor, even if not considered as a form of adulteration. Cocoa thus 
treated is generally darker in color than the pure article. 

The use of alkah is usually rendered apparent by the abnormally high 
ash, and by the increased alkalinity of the ash, the latter constant being 
expressed in terms of the number of cubic centimeters of decinormal 
acid necessary to neutrahze the ash of i gram of the sample. In pure, 
untreated cocoa, the ash rarely exceeds 5.5%, and the alkalinity of the 
ash is generally not more than 3.75. In cocoa treated with alkali, the 
ash sometimes reaches 8.5'^^, with the alkahnity running as high as 6 
or even 8. 

Microscopical Structure of Cocoa. — Fig. 80 shows elements of the 
powdered cocoa bean, both of the shell and of the kernel. The powder 
of the latter should constitute pure cocoa, with occasional fragments 
only of the shell. The irregular lobes constituting the kernel are each 
inclosed in a membrane made up of angular cells, filled with granular 
matter. (4), (5), and (6) show elements of the powdered cotyledons, 
or seed kernels. The polygonal tissue of the cotyledon is shown in cross- 
section at (4). In the powder one finds also dark granular matter, bits 
of debris, and fragments, with masses of yellow, reddish-brown, and 
sometimes violet coloring matter, together with numerous starch granules 
and aleurone grains. 

The starch granules are nearly circular, with rather indistinct central 
nuclei, and range in size from 0.0024 to 0.0127 mm., averaging about 
0.007 ^^- They are more often found in .single detached grains, but 
sometimes in groups of two or three. Occa.sional .spiral ducts, sp, are 
seen, but the.se are not abundant in the pure cocoa. 



404 



FOOD INSPECTION .4N D ANALYSIS. 



The masses of color pigment are shown up with striking clearness, 
according to Schimper, by applying a drop of sulphuric acid to the edge 
of the cover-glass and allowing it to penetrate the tissue. The bits of 
coloring matter are for a short time colored a brilliant red, which, how- 
ever, soon fades. Ferric chloride colors them indigo blue. 

Schimper recommends mounting the powder in a drop of chloral 
hydrate, which soon renders most of the tissues transparent. It is some- 
times necessary to allow the chloral to act on the powder in a closed 




-•-k ep 




Fig. 8o. — Cocoa under the Microscope. 

A. Powdered Cocoa under the Microscope. X125. (After Moelier.) i, cross-section 
through shell parenchyma; 2, thick-walled cells; 3, epidermis of shell (surface section); 
4, cross-section of cotyledon tissue; 5, 6, cotyledon parenchyma; 7, starch. 

B. Cocoa Shell in Surface Section. X160. e^, epicarp; />, parenchyma of the fruit; 
qu, layer of transverse cells. (After Moelier.) 



vessel for twenty-four hours, before all the elements, of pure cocoa are 
rendered transparent. If after that time opaque masses are still found, 
these are due to foreign material. 

Ammonia may be used instead of chloral with even better results, 
but this reagent requires longer treatment, soaking for several days or 
a week being sometimes necessary. 

Fig. 185, PI. XVII, shows the microscopical appearance of genuine 
powdered cocoa with its variously sized starch grains and the debris of 
the ground cotyledons. Fig. i86 shows cocoa adulterated with arrowroot. 



TEA, COFFEE, AND COCOA. 



405 



Cocoa Shells. — The shell parenchyma with side view of the stone- 
cell layer a and frequent spiral ducts, all characteristic of the ground 
shell, are shown at i, Fig. 80. 

In plan view the thick- walled stone-cell layer is shown at 2, and the 
spongy, outer seed-skin tissue, composed of two layers, with elongated 
cells running crosswise to each other in striated fashion, and with the 
underlying hairs or so-called " Mitscherlich bodies," is shown at 3. 
The presence of an abnormally large number of yellow and brown frag- 
ments in the water- mounted cocoa specimen, even under small magnifi- 
cation, arouses suspicion of the presence of shells, the most distinctive 
elements of which are the spongy tissue, the stone cells, and the abundant 
spiral ducts, the latter being scarce in pure cocoa powder. 

Cocoa shells are indicated on chemical analysis by the abnormally 
high ash, crude fiber and pentosans. 

Added Starch. — This can only be approximately determined by a 
careful examination with the microscope. Long experience will enable the 
analyst to familiarize himself with the appearance and abundance of 
starch grains of various kinds in a series of fields, so that he can roughly 
estimate the amount of each starch present in the mixture, by careful 
comparison with mixtures of known percentage composition. 

If the amount of starchy adulterant is considerable, evidence may be 
secured by determinations of starch by the diastase method and reducing 
matters by acid conversion. 

Added Sugar. — Any appreciable amount of added cane sugar is shown 
by the sweet taste. The amount of cane sugar may be determined by 
means of the polariscope, as described on page 399. 

An abnormally low ash is indicative of the addition of starch or sugar 
or both. 

Foreign Fat. — Certain manufacturers have found it profitable to 
remove a portion of the cocoa butter from chocolate and substitute for 
it a cheaper fat, such as cocoanut oil, tallow or even paraffine. Such 
adulteration is detected by determination of the physical and chemical 
constants of the fat obtained by extraction with ether. 

Dyes and Pigments, such as Bismark brown and Venetian red, have 
been employed to hide the presence of diluents. They are detected by 
dyeing tests, and by examination of the ash. 



4o6 FOOD INSPECTION AND ANALYSIS. 



REFERENCES ON TEA, COFFEE, AND COCOA. 

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Bertrand, G. Coffees without Caffein. Compt. rend., 141, 1905, p. 209. 
Beythien, a., Bohrisch, P., and Deiter, J. Beitrage zur Chemischen Untersuchung 

des Thees. Zeits. Unters. Nahr. Genuss., 3, 1900, p. 145. 
Clayton, E. G. Roasted Beetroot. Analyst, 29, 1904, p. 279. 
Crole, D. Tea: a Textbook of Tea Planting and Manufacture. London, 1897. 
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5, 1902, p. 761. 
Da\7ES, S. H., and McLellan, B. G. Amount of Cocoa Butter contained in the 

Cocoa Bean. Jour. Soc. Chem. Ind., 23, 1904, p. 480. 
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Am. Chem. Soc, 29, 1907, p. 556. 
Dyer, B. Chicory, and Variations in its Composition. Analyst, 23, 1898, p. 226. 
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Genin, V. Cafe, Chicoree, The, Mate, Coca et Cacao. Analyse des Matieres Ali- 

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Zeits. Unters. Nahr. Genuss., 11, 1906, p. 738. 
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KiRSCHNER, A. Die Bestimmung des Fettes in Kakao. Zeits. Unters. Nahr. Genuss., 

II, 1906, p. 450. 
KoENiG, J. Chemie der menschlichen Nahrungs- und Genussmittel. Vierte Aufl. 

Berlin, 1903. 
KUNZE, W. E. Quantitative Separation and Estimation of the Alkaloids of Pure 

Coffee. Analyst, 19, p. 194. 
Laxa, O. Ueber Milch-Schokoladen. Zeits. Unters. Nahr. Genuss., 7, 1904, p. 491. 
Lehmann, K. Die Fabrikation des Surrogatkaffees und des Tafalsenfes. Vienna, 

1893. 
Lendrich, K., und Murdfield, R. "Coffein-freier Kaflee." Zeitr. Unters. Nahr. 

Genuss., 15, 1908, p. 705. 



TEA, COFFEE, AND COCOA. 407 

Lodge, J. L. Coffee: History, Growth, and Cultivation; its Preparation and Effect 

on the System. London, 1894. 
LuDWiG, W. Die Bestimmung der Rohfaser in Kakao. Zeits. Unters. Nahr. Genuss., 

12, 1906, p. 153. 
LiJHRiG, H. Zur Kenntnis der Kakaoschalen. Zeits. Unters. Nahr. Genuss., 9, 

1905, p. 263. 

LUHRiG, H., and Segin, A. Pentosangehalt der Kakaobohnen und seine Verwertung 
zum Schalennachweis im Kakaopulver. Zeits. Unters. Nahr. Genuss., 12, 

1906, p. 161. 

Macfarlane, T. Coffee. Canada Inl. Rev. Dept. Buls. 3, 29, 31. 

McGiLL, A. Cocoa and Chocolate. Canada Inl. Rev. Dept. Bui. 72. 

Matthes, H., and Muller, F. Beitrage zur Kenntnis des Kakaos. Zeits. Unters. 

Nahr. Genuss., 12, 1906, p. 88. 

Die Bestimmung der Rohfaser in Kakaowaren. Ibid., p. 159. 

MiCHAELis, A. Der Kaffee als Genuss- und Heilmittel nach seinen botanischen, 

chemischen, dietetischen und medicinischen Eigenschaften. 
Orth, E. Beitrag zur Untersuchung und Beurteilung kandierter Kaffees. Zeits. 

Unters. Nahr. Genuss., 9, 1905, p. 137. 
Pearmain, T. H., and Moor, C. G. On the Adulteration of Coffee. Analyst, 20, 1895, 

p. 176. 
Smethane, a. Composition of Some Samples of Pure Coffee. Analyst, 7, 1882, p. 73. 
Spencer, G. L. Tea, Coffee, and Cocoa Preparations. Div. of Chem., Bui. 13, 

Part VII, 1892. 
Steinmann, a. Ueber die Bestimmung des Zuckers in Schokolade. Schw. Woch. 

Chem. Pharm., 40, 1902, p. 581; 41, 1903, p. 65. 
Trillich, H. Die Kaffeesurrogate, ihre Zusammensetzung und Untersuchung. 

Munich, 1889. 
W.'^NKLYN, J. A. Tea, Coffee, and Cocoa. London, 1883. 
Welmans, p. Zur Priifung von Schokolade auf den Gehalt an Zucker. Z. offent. 

Chem., 9, 1903, pp. 93 and 115. 

Kakao und Schokolade. Ibid., p. 206. 

WiGNER, G. W. Nitrogenous Constituents of Cocoa. Analyst, 4, 1879, p, 8. 
WiNTON, A. L., SiL\'ERM.\N, M., and B.ailey, E. M. Cocoa. An. Rept. Conn. Exp. 

Sta., 1902, p. 248. Chocolate. Ibid., 1903, p. 123. 
Wolff, J. Ueber die Zusammensetzung und die Untersuchung der Cichorienwurzel. 

Zeits. Unters. Nahr. Genuss., 3, 1900, p. 593. 
Yapple, F. Analyses of Cocoa. Amer. Jour. Pharm., 67, 1895, p. 318. 
ZiPPERER. The Manufacture of Chocolate and Other Cacao Preparations. 2d ed. 

Berlin, 1902. 
Conn. Exp. Sta. Annual Reports, 1896 et seq. 
Maine Exp. Sta. Bui. 65. Analysis of Coffee Substitutes. 
Massachusetts State Board of Health Reports, 1882 et seq. 
N. H. Sanitary Bui., Jan., 1906, p. 168. 

North Carolina Exp. Sta. Bui. 154. Adulteration of Coffee and Tea. 
Penn. Dept. of Agric. An. Rept., 1897, p. 178. Substitutes for Coffee. 
" " " 1898, pp. 75 and 548. Coffee and its Adulterations. 

" " " 1898, pp. 90 and 652. Chocolate and Cocoa. 



^ 



CHAPTER Xll. 

SPICES. 

These aromatic vegetable substances are classed as condiments, and 
depend for their use on the pungency which they possess in giving flavor 
or relish to food. As such seasoning or zest-giving substances, they are 
of considerable importance dietetically, but from the fact that they are 
used in comparatively insignificant amount, the determination of their 
chemical composition or actual value as nutrients per se is of little im- 
portance to the food economist. 

Spices are, however, of chief interest to the public analyst, because 
of all food materials they constitute from their nature a class more sus- 
ceptible than others to fraudulent adulteration of the most skilled variety. 

In many cases not only the megascopic appearance and taste of the 
skillfully adulterated article are made to counterfeit the genuine spice, 
but even the microscopical appearance is intended to deceive, since it 
is the microscope that is most useful in tlie detection of adulteration, and 
in many cases in the determination of the approximate amount of the 
adulterants. 

Indeed it is ver}' rare that the microscope will fail to detect the presence 
of any foreign substance in spice, and hence its use is indispensable in 
the study of this class of foods by the analyst. Chemical methods, as 
a rule, while of secondary importance, are, however, very helpful, both 
as confirmatory of the microscopical research, and in some cases show- 
ing instances of adulteration not readily apparent with the microscope, 
such, for example, as in the case of exhausted spices, or those deprived of 
a whole or a part of their volatile oil. Sophistication of this kind is best 
shown by the ether extract. 

General Methods of Proximate Analysis. — The following methods 
common to all the spices are for the most part those adopted provisionally 
by the A. O. A. C* Methods peculiar to special spices will be treated 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65 and Bui. 107 (rev.). 

408 



SPICES. 409 

under the discussion of the spice in question. For these determinations 
the spices should be powdered fine enough to pass through a 60-mesh 
sieve. 

Determination of Moisture. — Richardson^ s Method* — Two grams of the 
sample are weighed in a tared platinum dish and dried in an air-oven 
at 110° to a constant weight, which generally requires about twelve hours. 
The loss in weight includes the moisture and the volatile oil. The latter 
is determined from the ether extract, as described on page 410, and 
deducted from the total loss to obtain the moisture. 

McGill t determines the moisture by exposure of a weighed portion 
of the sample in vacuo over perfectly colorless sulphuric acid. The spice 
gives up its moisture before the volatile oil comes off, and any appreciable 
amount of the volatile oil, when absorbed by the acid, causes the latter 
to be discolored, so that by carefully observing the beginning of the dis- 
coloration, and removing the sample, the loss due to moisture may be 
obtained by weighing at the proper stage. The abstraction of the mois- 
ture in this manner requires about twenty-four hours. 

Determination of Ash. — Two grams of the spice are burned in a 
platinum dish heated to faint redness on a piece of asbestos paper by 
means of a Bunsen burner. The burning is best finished in a muffle 
furnace. If the ash contains an appreciable amount of carbon, it is 
exhausted on a filter with hot water, and the filter with the residue is 
burnt in the dish previously used. After adding the aqueous extract 
and a few drops of ammonium carbonate solution, the whole is evaporated 
to dryness and ignited at a faint red heat. 

The Water-soluble Ash % is found by boiling the total ash as above 
obtained with 50 cc. of water, and filtering on a tared Gooch crucible, 
the insoluble residue being washed with hot water, dried, ignited, and 
weighed. The insoluble ash, subtracted from the total, leaves the water- 
soluble ash. 

Sand. — This is assumed to be the percentage of ash insoluble in 
hydrochloric acid. The ash from 2 grams of the substance, obtained as 
above described, is boiled with 25 cc. of 10% hydrochloric acid (specific 
gravity 1.050) for five minutes, the insoluble residue is collected on a 
tared Gooch crucible, thoroughly washed with hot water, and finally 
dried and weighed. 

* U. S. Dept. of Agric, Dlv. of Chem., Bui. 13, pt. 2, p. 165. 

t Canada Dept. of Inland Rev. Bui. 73, p. 9. 

X U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 55; Bui. 107 (rev.), p. 162. 



4IO FOOD INSPECTION AND ANALYSIS. 

Lime is determined from the ash as directed on page 303, having first 
separated the iron and phosphates. 

The sulphuric acid due to calcium sulphate (added as an adulterant) 
is determined by precipitation with barium chloride of a ven/ weak hydro- 
chloric acid solution of the ash, the separated barium sulphate Ijeing 
washed, dried, ignited, and weighed. 

Ether Extract. — Total, Volatile, and Non-volatile.'^ — Two grams of the 
air-dry, i)ow(lcrcd substance are placed in some form of continuous 
extraction apparatus, such as Soxhlet's or Johnson's (pp. 63 and 68), 
and are subjected to extraction for sixteen hours with anhydrous, alcohol- 
free ether.t The ether solution is then transferred to a tared evaporating- 
dish, and allowed to evaporate spontaneously at the temperature of the 
room. After the disappearance of the ether, the evaporating-dish is 
placed in a desiccator over concentrated sulphuric acid and left over 
night, or for at least twelve hours, after which it is weighed, the residue 
in the dish being regarded as the total ether extract. 

The dish and its contents are then subjected to a heat of about 100° C. 
for several hours, taking a long time to bring the temperature up to that 
point so as to avoid oxidation of the oil. Finally heat at 110° C. till the 
weight is constant. The final residue is the non-volatile, and the loss 
in weight the volatile ether extract. 

Alcohol Extract.— Me//zo J 0/ Winlon, Ogden, and Mitchell. %— Two 
grams of the powdered sample are placed in a loo-cc. graduated flask, 
which is filled to the mark with 95% alcohol. The flask is stoppered and 
shaken at half-hour intervals during eight hours, after which it is allowed 
to stand for sixteen additional hours without shaking, and the contents 
poured upon a dry filter. Of the filtrate, 50 cc. are evaporated to dry- 
ness in a tared platinum dish on the water-bath, and heated at 110° C. 
in an air-oven to constant weight. This method, while only approxi- 
mate, is so much simpler than the tedious operation of continuous extrac- 
tion, considering the long time required, that it is regarded as preferable 
for ordinar}' work, and, unless great care is taken, is nearly as accurate. 

Determination of Nitrogen. — This, in spices other than pepper, is 
best done by means of the Gunning or Kjcldahl method (p. 69). 

* Richardson, U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 165. 

t Petroleum ether may be used, yielding results which difTer but slightly from those 
obtained with ethyl ether. As the latter has been used in the analyses of a large number 
of samples of spices, if these analyses are to be taken for standards of comparison it is evi- 
dent that the same solvent should be used. 

X U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 56; Bui. 107 (rev.), p. 163. 



SPICES. 411 

Determination of Starch. — In spices like white pepper, ginger, and 
nutmeg that normally contain a high content of starch and ver)- little 
other copper-reducing matter, the direct acid conversion process of starch 
determination is satisfactor)'. 

. In spices normally free from starch, such as cloves, mustard, and 
cayenne, where a starch determination indicates the amount of a foreign 
starch present as an adulterant, it is safer to use the diastase process. 

Four grams of the powdered sample are extracted on a filter-paper 
(fine enough to retain all starch particles) first with five successive por- 
tions of 10 cc. of ether, then with 150 cc. of 10% alcohol. Owing to 
difficulty of filtering in the case of cassia and cinnamon, Winton recom- 
mends that all washing in the determination of starch in these substances 
be omitted. The residue is washed from the filter-paper by means of 
a stream of water into a 500-cc. flask, if the direct acid conversion method 
is used, using 200 cc. of water; 20 cc. of hydrochloric acid Cspecific 
gravity 1.125) are added, and the method from this point on followed, 
as detailed on page 283. 

If the starch is to be determined by the diastase method, wash the 
residue from the filter-paper into a beaker with 100 cc. of water, and 
proceed as on page 283. 

Determine the dextrose in either case by the Defren or Allihn methodi 
or volumetrically, and convert dextrose to starch by the factor 0.9. 

Determination of Crude Fiber. — Two grams of the substance are 
extracted with ordinar}' ether (or the residue left from the determination 
of the ether extract may be taken) and subjected to the regular methcxi 
for determining crude fiber, by boiling successively with acid and alkali 
(page 277). 

McGill recommends the use of the centrifuge in separating the crude 
fiber, after boiling with the alkaline solution. 

Determination of Volatile Oil. — Method 0} Girard and Dupre* — 
The spice is mixed with water and subjected to distillation, receiving 
the distillate in a graduated cylinder. The volume occupied by the 
essential oil (which is immiscible with water) can be thus rea<l off and 
its content roughly determined. If the volatile oil is slightly soluble 
in water, separate out the water layer, having first read the volume of 
the oil layer, and extract the aqueous solution with petroleum ether. 
Evaporate the petroleum ether extract to dryness at room temperature 

* Analyse des Matieres Alimentaires, 2nd ed., p. 787. 



412 FOOD INSPECTION AND AN /I LYSIS. 

in a tared dish, and add the volume due to the weight of the residue to 
the volume read off in the graduate. 

Microscopical Examination of Powdered Spices. — As a rule few 
microscopical reagents arc necessary in the routine examination of 
powdered spices for adulteration, unless a more careful study of the 
structure than is necessary to prove the presence of adulterants is desir- 
able. The simple water-mounted specimen is usually sufficient to show 
the purity or otherwise of the sample. If in doubt as to the presence oi 
search in small quantities, iodine in potassium iodide should be appHed 
to the specimen, well rubbed out under the cover- glass. 

The tissues may be cleared by adding to the water mount a small 
drop of 5% sodium hydroxide, or by soaking a portion of the spice for a 
day in chloral hydrate solution. A valuable means of clearing dense 
tissues is to boil about 2 grams of the material successively with dilute 
acid and alkali as in the crude fiber process (p. 277), decanting (not 
filtering) the solution after each boiling. 

The presence of occasional traces of a foreign substance, when viewed 
under the microscope, is hardly sufficient to condemn the sample as 
adulterated, since such traces are apt to be accidental. 

Composition of Miscellaneous Spice Adulterants. — The chemical 
analyses of various spice adukerants commonly met with are given on 
page 413. 

CLOVES. 

Nature and Composition. — Cloves are the dried, undeveloped flowers 
of the clove tree (Caryophyllus aromaticus or Eugenia caryophyllata)^ 
which belongs to the myrtle family (Myrtacece). The tree is an evergreen, 
from twenty to forty feet in height, cultivated expensively in Brazil, Cey- 
lon, India, Mauritius, the West Indies, and Zanzibar. Its leaves are 
from 7.5 to 13 mm. long, and its flowers, of a purpHsh color, grow in 
clusters. The green buds in the process of gro\\th change to a reddish 
color, at which stage they are removed from the tree, spread out in the 
sun, and allowed to dry, the color changing to a deep brown. Each 
whole clove consists of a hard, cylindrical calyx tube, having at the top 
four branching sepals, surrounding a ball-shaped casing, which consists 
of the tightly overlapping petals, and \Anthin which are the stamens and 
pistil of the flower. In taste the clove possesses a strong and pecuHar 
pungency. One of its most valuable ingredients is the volatile clove 
oil. This is composed largely of eugenol (C,oHi202), which forms 70 to 



SPICES. 



413 



COMPOSITION' OF SPICE ADULTERANTS. 



English-walnut shells*. 

Brazil-nut shells * 

Almond shells * 

Cocoanut shells * 

Date stones * 

Spruce sawdust * 

Oak sawdust * 

Linseed meal * 

Cocoa shells * 

Red sandalwood * 

Ground olive stones t • 
Buckwheat hulls 



7.69 
9.08 
7.80 
7-36 
8.24 
8.77 

5-73 
8.71 
10.44 
4.42 
9-50 
7-63 



Ash. 



1.40 

1-59 
2.86 

0.54 
1.24 
0.23 
1.22 

5-72 
8.40 
0.70 
0.88 
1.84 



3 0! 
•3^ 



0.77 
1.06 

2-39 
0.50 
0.76 
0.16 
0.32 

1-74 
4.66 
0.28 
0.24 

1.24 



0.00 
0.17 
0.05 
0.00 
0.04 
0.00 
0.02 



o. 



.•>:> 



0.83 
0.07 
0.44 

0.00 



Ether Extract. 



0.12 
0.07 
0.16 
COO 

0.36 

0.07 
0.07 
0.04 
1. 00 

1.21 
0.06 

0.07 






0-55 
0-S7 
0.64 
0.25 
8.38 
0.77 
0.84 
6.58 

2-99 

11.47 

0.24 

0.38 



1.84 
1. 01 
5-16 
1. 12 
16.72 

1-50 
6.25 
9.46 
4-77 
19.37 

2.17 



>• 1 

^ K c ^ 



SQS 






^2<a 



1<l 






English-walnut shells*. 

Brazil-nut shells * 

Almond shells * 

Cocoanut shells * 

Date stones * 

Spruce sawdust * 

Oak sawdust * 

Linseed meal * 

Cocoa shells * 

Red sandalwood * 

Ground olive stones f . 
Buck%vheat hulls 



19.30 
12.96 
22.72 
20.88 
20.88 
15-48 
17.10 
21.15 
8.68 
6-79 



1. 01 

0-73 
0.84 

0-73 
2.19 

1-13 

1.68 

14.06 

3-15 



56. 
50. 
49. 
56. 
5- 
64. 

47- 

8. 

14. 



58 



20. ; 



1.69 
4.19 
1-75 
1-13 
5-31 
0.56 

1-63 
31.81 
16.19 

3.06 

-- ,^ ./. -T . l-°6 

1.46 I 43-76 I 3-06 



.12 1 52 

1-73 i 57 



19 

72 

03 
79 
30 
12 

30 
46 I 
76 



0-53 
0-33 
0.40 
0.47 
0.61 
0.30 

3-^3 
1. 00 
1.26 
0-59 



2.08 
1.30 
1.56 
1.82 

2.34 
1. 17 
12.22 
3-90 
4-94 
2.29 



0.27 
0.67 
0.28 
0.18 
0.85 
0.09 
0.26 
5-09 
2.59 
0.49 
0.17 
0.49 



75 per cent of the oil, and a sesquiterpene kno\\Ti as caryophyllene. 
There are also in cloves a notable amount of fixed oil and resin, and also 
a peculiar form of tannin. 

Yen,' few complete analyses of cloves are on record. Richardson t 
seems to have been the earliest worker in the field to give anything at 
all satisfactor}' in the way of a number of determinations of value. 

The following are maximum and minimum figures from the tabu- 
lated results of Richardson's analyses: 

♦Winton, Ogden, and Mitchell, Conn. Exp. Sta. An. Rep., 1898, p. 210. 
t Doolittle, Mich. Dair\- and Food Dept. Bui. 94, 1903, p. 12. 
X U. S. Dept of Agric, Div. of Chem., BuL 13. 



414 



FOOD INSPECTION AND AN /I LYSIS. 





u 


< 


00 




^1 




1 

2 


Oxygen 
Equivalent. 

As Ouerci- 
tannic Acid. 


Whole cloves (7 samf 


les): 


ro.67 

2.90 

ro.i8 

9-S8 


13-05 
5-50 
6.96 


18.89 
10.23 

4.40 

13-93 
3-94 


10.24 
7.12 
4.03 


9-75 

6.18 

13-58 


7- 

4-73 

5-78 

6.48 
4.20 


1. 12 

1.04 

-70; 


5.43 22.13 


Minimum 


3.00 1 1.70 




5-96 

6.20 
2.89 


23-24 


Ground cloves (9 sair 


pics) : 


7-44 


1^.80 


24.18 


Minimum 


5.93I "(.TO 


4.02I 9-38 


11.28 






1 '■ 






1 





McGill * gives tables of analyses of pure and adulterated samples of 
cloves. Analyses of ujjwards of twenty samples of genuine cloves, both 
whole and ground, from these tables show the following maximum and 
minimum figures: 



Moisture 

Volatile oil 

Total volatile matter 

P'ixed oil 

Total extraction. 

Ash 



Maximum. 


Minimum. 


11.80 


5-05 


19.63 


9.24 


30.68 


16.25 


10.23 


C.94 


31.40 


22.23 


7.00 


5-03 



McGill also made analyses of whole cloves of several varieties, the 
following tal)le being a summary of his results: 



No. of 
Analyses. 



Moisture. 



Total 
Volatile 
Matter. 



Volatile 
Oil. 



Total 
Extract- 
ive 
Matter. 



Fixed 
Oil. 



IVnang cloves: Maximum 

Minimum. 

Mean 

Amboyna cloves: Maximum 

Minimum. 

Mean. . . . 
Zanzibar cloves: Maximum 

Minimum. 

Mean .... 



7-4 
5-0 
6.2 
6.7 

5-5 
6.1 
6.7 
4-1 

5-7 



24-3 
20.7 
22.4 
25-9 
23-5 
24.6 
23.6 
18.6 
21.7 



17.2 


28.2 


12.0 


14.8 

16.2 


24-4 
27.0 


9-5 
10.8 


19.2 
18.0 


29.2 
26.5 


10. 
8.2 


18.5 
18.3 


27-5 
28.1 


9.0 
10.7 


12. I 
16.0 


21.3 
25-5 


8.0 
9.6 



Maximum and minimum figures of thirteen samples of unadulterated 
cloves, as purchased from retail dealers in Connecticut and analyzed 
by Winton and Mitchell, f are as follows: 

* Canada Inland Rev. Dcpt. Bui. 73. 

t Conn. Exp. Sta. Rep., 1898, pp. 176-177 



SPICES. 



415 



1 Maximum. 


Minimum. 


Ash total ' 7-92 


5-99 


Ether extrax:t, volatile 18.25 

" " non-volatile 7- 19 


11.03 
4-87 



Winton, Ogden, and Mitchell * give more complete analyses of eight 
samples of whole cloves of known purity, representing Penang, Amboyna, 
and Zanzibar xarieties, and two samples of clove stems, as follows: 



1 




Ash. 


Ether Extract. 




! Mcnsture. 


TotaL 


Soluble in 
Water. 


Insoluble 
in Ha. 


Volatile. 


Non- 
volatile, 


Extract. 




8.26 

7-03 
7.81 

8.74 


6.22 
5-28 
5-92 
7-99 


3-75 
3-25 

4.20 


0.13 
0.00 
0.06 
O-60 


20.53 

17.82 

19.18 

5.00 


6.67 
6.24 
6.49 
3-83 


15-58 


Minimuni. . 


13-99 


Mean 


14.87 


Clove stems, mean 


6.79 




Reducing 

Matters starch by 
by Acid Diastase 
Cpnver- Method, 
sion.as 
Starch- | 


Crude 
Fiber. 


Nitrogen, 
X6.2S. 


Oxygen 
Absorbed 
by Aque- 
ous Ex- 
tract. 


Qucrci- 
tannic 
Acid. 


Total 
Nitrogeru 




9-63 3-15 
8.19 j 2.08 

8.00 2.7J. 


9.02 

7.06 

8.10 

18.71 


7.06 
5-88 
6.18 

5-88 


2.63 
2.08 
2-33 


20.54 
16.25 
18.19 


I-I3 


Minimum. . .......... 


0.94 


Mean 


0.99 


Clove-stems, mean 


f4-I3 


1 2.17 


2.40 


! 18.79 


0.94 



The Tannin Equivalent in Cloves. — The amount of tannin in cloves 
was show^n by Ellis to be so constant as to be of valuable assistance as a 
guide to their purity. The actual determination of tannin is, however, 
a long and difficult proceeding, and Richardson t has pointed out that 
it is not necessary, but that simply using the first part of the Lowenthal 
tannin process, and noting the "oxygen absorl^ed" as expressed by the 
oxidizing power of permanganate of potash on the material after extrac- 
tion with ether, is quite as useful as determining the tannin, and is in 
effect proportional to the tannin present. The result is sometimes 
expressed as in Richardson's figures above, as the oxygen equivalent, or 
as quercitannic acid. 

Determination of Tannin Y.(\v\vB\eni.X— Reagents: Indigo Solution.— 
Six grams of the indigo salt § are dissolved in 50 cc. of water by heat- 

* Conn. Exp. Sta. Rep., 1898, pp. 206, 207. 

t U. S. Dept of .^gric, Div. of Chem., BuL 13, p. 167. 

J U. S. Dept. of .\gric., Bur. of Chem., Bui. 65, p. 60; Bui. 107 rev., p. 164. 

I The quality of the indigo usefi Ls of great imfxjrtance since with inferior brands it is 



4l6 FOOD INSPECTION AND ANALYSIS. 

ing. After cooling, 50 cc. of concentrated sulphuric acid are added, 
the solution made up to a liter and filtered. 

Standard Permanganate Solution. — Dissolve 1.333 gra-ms of pure 
j)otassium fjcrmanganate in a liter of water. This should be standardized 
by titrating against lo cc. of tenth-normal oxalic acid (6.3 grams pure 
crystallized oxalic acid in 1,000 cc), diluted to 500 cc. with water, heated 
to 60° ('., and mixed wilh 20 cc. of dilute sul[;huric acid (i : 3 by volume). 
The permanganate solution is added slowly, stirring constantly, till a 
pink color aj^pears. 

Two grams of the material are extracted for twenty hours with pure 
anhydrous ether. The residue is boiled for two hours with 300 cc. of 
water, cooled, made up to 500 cc, and filtered. 

Twenty-five cc. of the filtrate are pipetted into a 1200-cc. flask, 750 cc. 
of distilled water are added and 20 cc. of indigo solution. 

The standard permanganate solution is then run in from a burette 
a drop at a time with constant shaking, until a bright golden yellow color 
appears, which indicates the end-point. Note the number of cubic cen- 
timeters required, represented by {a). 

In a similar manner determine the number of cubic centimeters of 
standard permanganate solution consumed by 20 cc. of the indigo solu- 
tion alone, represented by {h), and subtract this from (a). 

The oxygen equivalent, or, as it is sometimes called, the "oxygen 
absorbed," is calculated from the equivalent in tenth-normal oxalic acid 
of the number of cubic centimeters of standard permanganate repre- 
sented by a—b. 10 cc. of tenth-normal oxalic acid are equivalent to 
0.008 gram of oxygen aljsorbed, or 0.0623 gram of quercitannic acid. 

Microscopical Examination of Cloves. — Unless the finely powdered, 
water-mounted sample is well rubbed out under the cover-glass, many 
of the masses of cellular tissue will be too dense to recognize. With a 
little care, however, it is possible to make a very satisfactory water mount, 
though })y soaking for twenty-four hours in chloral hydrate solution the 
more opaque masses are rendered very translucent. 

Fig. 81, from Moeller, shows some of the characteristics of p-^wdered 
cloves. The outer skin of the calyx tube is shown at (i) with its polyg- 
onal cells and large oil spaces showing through them; (2) shows the 
epidermis of the outer part of the lobes or wings of the calyx, with stomata 



impossible to get a sharp end-point. The indigo solution should be made from the very 
best variety of sulphindigotatc, which may be obtained from Grueber& Co., of Leipzig, or 
Gche & Co., of Dresden, under the name of carminium cwruleum. 



SPICES. 4f7 

surrounded by irregularly shaped cells; (3) represents the epidermis 
of the petals, with crystals of calcium oxalate; a cross-ssection of the epi- 
dermis of the calyx Ls shown at (4); (5) shows the parenchyma, with 
calcium oxalate crystals and with one of the slender spiral ducts; (6) 
and (-]) represent in cross-section and longitudinal section respectively 
the parenchyma of the middle layers of the ovary, one of the rounded, 
triangular pollen grains being shown at (12). 




k 
Fjg. 81.— Powdered Clovci urificr ll-t Microscope. X125. (After Moelk-r.) 

Characteristics of clove stems, which are frequently used as adulter- 
ants of cloves, are found in (8), C9), Cio), and CiiJ. Stone cells of 
the outer skin and the inner portion of the clove stem are shown 
at (8) and (g) respectively; Cio) shows one of the vascular ducts, 
and (11) two of the bast fibers. Both the vascular ducts and the 
stone cells are ver}- characteristic of clove stems. Pure cloves have no 
..tone cells and comparatively few bast fibers. Stems under the micro- 
sco[>e show a large number of bast fibers and frequent stone cells, the 
latter being of a distinctly yellow color. 

A plain water-mounted slide rarely shows all the structural details 
depicted in Fig. 81, but is nearly always s-ufhciently characteristic to 



4fS lOOl) INSriJ.IION AN I) ANALYSIS. 

prove the puriiy iA ihc :,.'iriii<lc. J' i^. 2;^o, I'l. XX V^, shows the actual 
;ip)H;ir;irK (• iA povvflcrcd cloves, mf>unt(;fi in water anrl examined under 
a iii;i|nii(ic;i,liori of i ^o. 'I'lie general aj^fjearance of the celluhir tissue 
is lh;it of a loose, sjxMigy mass filled with brown, granular material. 
Throughout the masses of tissue are to be seen small oil globules. 

Cloves h.'ive nu slJinh whatever. Aside frr^m the stems, cloves are 
sometimes adulterated with clove fruit or "mother cloves," which have 
a sm<'ill ;i,monnt of a sago like starch, and also contain some stone cells. 

Adulteration of Cloves. — The U. S. standard for pure cloves is as 
follow,: Vol;i.tilc cllicr extract not less than io%; fjuerritannic acid, cal- 
(ulated fnjtn the tot.'d oxygen absorbed by the aqueous extract, shoulrl 
not be less th;in \2^'/,,\ tfjtal ash should not (-xceed 8%; ash insfjluble in 
hydrfx hlorif ar if! should not exfeed 0.5%, and crude fiber shouUl not 
be more than 10%. 

Clove Stems are very frecjuent adulterants of cloves and possess some 
slight [»ungeri(y. They are commf)nly identified under the microsco[)e 
by the large number of ba.st fibers a.nf| stone (ells, and should not be 
found in pure ( lov(;s in excess fjf 5%. 

Allspice, being (onsiderably cheaper than (lo\'es, is sometimes used 
as an adult(;ra.iit. It is rea.dily recf>gni/ed by the ( haracteristics described 
on page 422. 

Other Adulterants commfMily found are cereal starches (esf^ecially 
(orn and wheat) and ginger ('for the most part "(exhausted"). Besides 
the above, pea. starch, rice, turmeric , eharcoal, sand, pepper, grounrl fruit 
stones, and sawdust have been found in samjJes of clmes examined in 
Massachusetts. 

Exhausted Cloves, bolli whole and in powdered frjrm, are not infre- 
(|uently found on the- market. These hav(; been dej^rived of a jjortion 
of the volatile oil, and are much less [)ungent than the pure article, so 
that the difference in taste between the two varieties is f|uite marked. It 
is, however, rare that |)Owdered clovers are sold consisting entirely of 
the exhausted variety, the more common jjracticc- being tc) mix from 
10 to 25 j)er cent of exhausted cloves with the pure ]>owder, so that the 
sophistication is less apparent. 

A determination of the volatile oil is the only reliable means of show- 
ing whether or not the material has been wholly or in jnirt exhausted, 
though Villier and Collin claim that under the microscoj^e an exhausted 
sample of (loves shows the oil glands to be nearly emj^ty, or to inclose 
much smaller droplets of oil than the j)ure variety. 



SPICES. 



4f9 



With the exception of exhausted cloves, the 7)rescnce of nearly 
cverj' foreigji ingredient is best and most quickly shown by the use of 
the micn>scofx;, though much information as to the purity of the samf>lc 
can Ik; gained by the ether extract, the percentage of ash, and of crude 

Cocoanut Shells. — Figs. 226 and 227, PI. XXVII, show samples of cloves 
a/lulterated with ground cocoanut shells. The long, spindle-shaperl, yellow- 
brown and deeply furrowerl stone cells of the adulterant with their thick 
walls and central branching fxjres are unmistakable. The rlark-brown 
contents of the cells turn reddish brown when treated! with pr^tassium 
hyrlroxide. The anatomy of the crx:oanut, including the shell, has been 
carefully studied by Winton.f 

Fig. 82, after Winton, shows elements of powdercrl cocfjanut .shell 
under the microsajjx.-. st are the dark, elongated, yellow, porous stone 




Fic. 82. — r>>coanut-«hell Vow'urr. xt, (lnTk-yel]ffw stone cclk with brown contents; 
/, reticulntcA tra/:hca; sp, spiral trathca; g, jntted trar;hca; w, coloHeM, and ir, 
\frfmn, parenchyma frf mesocary*; /, ba»t fiV/re«, with »te^mata r«fe). yrfo, (After 
Winton.) 

cells with their Vjrfjwn contents, these stone cells Ix.-ing the most dis- 
tinctive characteristic of the ground shells. /, sp, and g are the various 
forms of trachea; w and br art respectively aJorless and brown paren- 
chyma of the mesrx^rp or outer coat, portions of which always arJhere 
to the nutshell and are ground with it. 

* Xotc especially the »harp diatinrtion between thexc values in the ca«c of ptire doves 
and of clove stems in Richardson's table. 

t The .\natr>my of the Fruit 'A the Cocoanut. Conn. Exp. Sta. Rep., u/Ci, p. 20^.. 



42o 



FOOD INSPECTION /1ND ANALYSIS. 



Fig. 264, PL XXXVI, shows a photomicrograph of powdered cocoanut 
shells, mounted in gelatin. The long, spindle-shaped stone cells are 
especially apparent, 

Ground cocoanut shells have been used in various spices besides 
cloves, especially allspice and pepper. In the following tabulated 
results of analyses by Winton, Ogden, and Mitchell * are shown the wide 
deviation between the chemical constants of cocoanut shells and several 
of the spices in which they appear as adulterants. 



Black 
Pepper. 



Cloves. 



Allspice. 



Nutmeg. 



Cocoanut 
Shells. 



Water 

Total ash 

Ash soluble in water 

Ash insoluble in hydrochloric acid 

Volatile ether extract 

Non-volatile ether extract 

Alcohol extract 

Reducing matters, as starch, acid conversion 

Starch by diastase method 

Crude fiber 

Total nitrogen 

Oxygen absorbed by aqueous extract 

Quercitannic acid equivalent 



II 


g6 


4 


76 


2 


54 





47 


I 


14 


8 


42 


Q 


62 


3« 


63 


,S4 


15 


n 


06 


2 


26 



18 



9.78 

4-47 
2.47 
0.03 
4-05 
5-84 
11.79 
18.03 

3 -04 
22.39 
0.92 
1 . 24 
9.71 



3-63 

2.28 

0.86 

0.00 

3.02 

36.70 

10.77 

25 56 

23.72 

2-51 
1.08 



■36 

•54 
•50 
.00 
.00 



20.88 

0-73 
56.19 
0.18 
0.23 
1.83 



ALLSPICE, OR PIMENTO. 

Nature and Composition. — Allspice is the dried fruit of the Eugenia 
pimenta, an evergreen tree belonging to the same family {Myrtncea) 
as the clove. It is indigenous to the West Indies, and is especially cul- 
tivated in Jamaica. 

The allspice berry is grayish or reddish brown in color, and is hard 
and globular, measuring from 4 to 8 mm. in diameter, being surmounted 
by a short style. This is imbedded in a depression, and around it are 
the four lobes of the calyx, or the scars left by them after they have fallen 
off. The berr}^ has a wrinkled, ligneous pericarp, with many small 
excrescences filled with essential oil. The pericarp is easily broken 
between the lingers, showing the berry to be formed of two cells with a 
single, brown, kidney-shaped seed in each, covered with a thin, outer 
coating, inclosing an embryo rolled up in a spiral. 

The berries are gathered when they have attained their largest size, 
but before becoming fully ripe. If allowed to mature beyond this stage, 
some of the aroma is lost. 



* Conn. Ag. Exp. Sta. Rep., 1901, p. 225. 



SPICES. 



421 



Though considerably less pungent than other spices, allspice possesses 
an aroma not unhke cloves and cassia. In chemical composition it most 
resembles cloves, containing both volatile oil and tannin; but, unhke 
cloves, it contains much starch, the starch being contained in the seeds. 
The volatile oil of allspice is very similar to clove oil. It is shghtly laevo- 
rotary, and is composed of eugenol and a sesquiterpene not determined. 
It is present in allspice to the extent of 3 to 4.5 per cent. The boihng- 
point of the oil is 255° C. 

Authoritative full analyses of allspice are even more meager than 
of cloves. Analyses of one sample of whole allspice and five samples 
of the ground spice, made by Richardson,* are thus summarized: 





















s 


•d 




u 


< 


|5 


S5 


II 




c. 


c 

s 


c > 


£-3 


Whole 


6.19 


4.01 


5-15 


6.X5 


59.28 


14.83 


4-38 


.70 


10.97 


2.81 


Ground: 




Maximum 


8.82 


5-53 


3-32 


6.92 


58.24 


18.98 


5-42 


.87 


12.74 


3-36 


Minimum 


5-51 


3-45 


2.07 


3-77 


56.86 


13-45 


4-03 


.64 


8.27 


2.12 



Seventeen samples of unadulterated allspice, as sold on the Connect- 
icut market, were analyzed by Winton and Mitchell ,t with maximum 
and minimum results as follows: 



Ash. 


Maximum. 


Minimum. 


Total 


7-51 

-95 

3-50 

6.22 


4-34 
.40 

1-34 
3-78 


Insoluble in hydrochloric acid (sand) . . 
Ether extract, volatile 


Ether extract, non-volatile 





Three samples of pure whole aUspice were more fully analyzed by 
Winton, Mitchell, and Ogden with the results given on page 42 2. J 

The Tannin Equivalent in Allspice. ^Tannin is present in allspice, 
though to a less extent than in cloves. The exact amount present is 
rarely determined, but rather the "oxygen equivalent," or quercitannic 
acid, as explained on page 415, the determination being carried out as 
there detailed. 



* U. S. Dept. of Agric, Div. of Cham., Bui. 13, p. 229. 
t An. Rep. Conn. Exp. Sta., 1898, pp. 178, 179. 
J Ihid., pp. 208, 209. 



FOOD INSPECTION AND ANALYSIS. 



Moisture. 



Ash, 



Total. 



Solu>>le 
in Water. 



InsoluVjle 
in HCl. 



Ether Extract. 



Volatile. 



Non- 
volatile. 



Alcohol 
Extract. 



Maximum 
Minimum 
Average. . 



10.14 

9-45 
9.78 



4.76 
4-15 
4-47 



2.6g 
2.29 

2.47 



.06 
.00 
■03 



5-21 

3-38 

4-05 



7.72 

4-35 
5-84 



14.27 

7-39 
11.79 



Reducin)? 
Matters gtarch 
by Acid ; by 
Cpnver- Diastase, 
sion, as ' 
Starch, i 



Crude 
FiV^r. 



Nitrogen, 
X6.2S. 



Oxygen 




AbsorVjed 


Querci- 


by Aque- 
ous Ex- 


tannic 


Acid. 


tract. 




1-59 


12.48 


1-03 


8.06 


1.24 


9.71 



Total 
Nitrogen. 



Maximum 
Minimum 
Average . . 



20 . 65 
16.56 
18.03 



3-76 
1.82 
3-04 



23.98 
20.46 
22.39 



^^-37 
5-19 
5-75 



.02 

-83 
.92 



Microscopical Examination of Powdered Allspice. — By soaking the 
powder twenty-four hours or more in chloral hydrate, many of the harder 
portions arc rendered much more transparent than would otherwi.se 
be possible. Fig. 83, after Moeller, shows the microscopical structure 
of various elements that go to make up allspice powder. 

The epidermis, or outer layer of the berry, is shown at (la)in cross- 
section, and in plan view at (2) with its small cells. Just beneath the 
outer coat are the large oil spaces (i^) and still further below the stone- 
cells (ic). The fruit parenchyma (3) has vascular tissues running through 
it. (4) and (5) are the inner epidermis and stone cells of the dividing 
partitions between the seeds. Small hairs connected with the outer 
epidermis are shown at (6). (7) and (8) show in cross-section a portion 
of the seed-shell and inclosed seed ox cmljryo, with the starch (8a) and 
the colored lumps of gum or resin (8ftj of a port-wine color. These colored 
cells exist in the seed coating, and, although only one is here shown, 
constitute a very important and striking characteristic of allspice. (9) 
represents the spongy parenchyma of the seed shell, and (10) shows its 
epidermis. In the parenchyma of the fruit and of the partitions between 
the cells are seen, but not always plainly, minute crystals of calcium oxa- 
late (see (4) and (5)). 

These details so closely drawn by Moeller are idealized, but serve 
well to indicate what should be looked for. In practice the water- 
mounted specimen shows all the characteristics necessary to irientify 
pure allspice, and most if not all its adulterants. In fact pimento is one 
of the easiest spices to identify under the microscope, by reason of its 
striking characteristics. 



SPICES. 



423 



Three distinctive features are especially typical, viz. : First, the starch 
grains, which are ver)- uniform in size, measuring about 0.008 mm. in 
diameter, being nearly circular as a rule, and often arranged in groups 
not unUke masses of buckwheat starch. Ordinarily these masses con- 
tain fewer granules than do those of buckwheat. The granules are 




-r^i^^O 



r^-3 






Fkj. *3 — Powdered Allspice under the ificroscope. X125. (After Moeller.) 




smaller end more inclined to the circular ihan to the polygonal form, 
while in many cases they have distinct central hila. The starch grains 
are ver}' numerous and are found in nearly every field. See Fig. 195, PI. 
XIX. 

A second distinctive feature of allspice is the stone cells, of which there 
are many. These are more often colorless, and in most cases very large 
and plainly marked. They are sometimes seen singly and at other 
times grou[x,'d together. Frequently they are attached to pieces of brown 
parenchj-ma. 



424 FOOD INSPECTION AND ANALYSIS. 

The third and most characteristic feature of allspice powder under 
the microscope is the striking appearance of the lum])s of gum or resin, 
which are of a more or less deep port-wine or amber color and are con- 
tained in th.e middle layers of the seed coat. These cells are very 
striking, occurring sometimes in isolated bits, and in other cases in aggre- 
gations of from 2 to 4 or even 6 to 8 cells. These resinous lumps appear 
plainly in Fig. 194, PI. XIX. Droplets of oil are occasionally seen, but 
not in profusion. As a rule the oil is forced out of its large containing 
cells and into the surrounding tissue by the process of drying. 

Adulteration of Allspice. — According to the U. S. standard for all- 
spice, quercitannic acid should not be less than 8%, total ash not more 
than 6%, ash insoluble in hydrochloric acid not more than 0,5%, crude 
fiber not more than 25%. The most common adulterants found in 
powdered allspice are cocoanut shells and the cereal starches. Besides 
these the writer has found in Massachusetts, peas, pea hulls, exhausted 
ginger, cayenne, olive stones, pepper, and turmeric. To this list may 
be added clove stems, which are on record as a not uncommon adulterant 
in some localities. All of these are to be readily recognized by a care- 
ful microscopical examination. 

CASSIA AND CINNAMON. 

Nature and Composition. — The terms cassia and cinnamon are 
interchangeable in commerce, though, strictly speaking, they represent 
two separate and distinct species of the genus Cinnamomum, belonging 
to the laurel family (LauracecE). True cinnamon is the bark of Cinna- 
momum zeylanicum, a tree from 20 to 30 feet high, having horizontal 
or drooping branches, and native to the island of Ceylon, but cultivated 
also in some parts of tropical Asia, in Sumatra, and in Java. The entire 
yield of pure Ceylon cinnamon is extremely small, and but Httle of it is 
found in this country. It is the very thin, inner bark of the tree, and is 
of a pale, yellowish-brown color, being found on the market in long, cylin- 
drical, quill-like rolls or pieces, the smaller rolls being inclosed in the 
larger. The outer surface is marked by round dark spots, correspond- 
ing to points of insertion of the leaves, and it is also furrowed length- 
wise by somewhat wavy, light-colored lines. The inner surface of the 
bark is darker colored, and has no lines. In thickness the bark varies 
from 1.5 to 3 mm. Both the inner and outer coatings of the bark of 
Ceylon cinnamon are usually removed in the process of preparation, so 



SPICES. 



42 = 



that it is of a much cleaner and more even texture than the cassia bark, which 
is thicker and heavier by reason of the outer cork layer usually left on it. 

The cheaper and more common cassia is the bark of the Cinna- 
momum cassia, which comes from China, Indo-China, and India. It is 
of a darker color than that of cinnamon, of coarser texture, and as 
a rule about four times as thick. Most varieties of cassia bark are less 
tightly rolled than cinnamon, and are not arranged one within the other 
in layers. The outer surface is marked by elHptical spots left by the 
leaves, and by small, dark-brown, wart-hke protuberances. Cassia does 
not have the wavy, Hght-colored hnes found in the cinnamon. Both 
cinnamon and cassia barks are very aromatic in taste, somewhat astrin- 
gent, and slightly sweet. 

Cassia buds are the dry flower buds of China cassia, and are found 
in the market both in whole and in powdered form. Powdered cassia 
often 'consists of a mixture of several varieties of bark, while the cheaper 
grades sometimes contain an admixture of the ground buds. 

The best grade of cassia is that from Saigon, a much cheaper, from 
Batavia, while the cheapest is the China cassia. 

The odor of cassia and cinnamon bark is due to the volatile oil, of 
which from i to 2 per cent is usually found. Cassia and cinnamon oil 
greatly resemble each other, the principal constituent in either case being 
cinnamic aldehyde, CeH^CHiCH.CHO. Besides this, one or more esters 
of acetic acid are present. Both oils are ver}' pungent and intensely sweet. 

Starch is present in cassia to the extent of from 16 to 30 per cent. 
A ver>' small amount of tannin is found, as well as cinnamic acid and 
mucilaginous matters. Cassia buds are somewhat similar in com- 
position to the bark. They have, however, less starch and crude fiber, 
and higher contents of volatile oil and nitrogen than the bark. 

Richardson * has made analyses of a few samples of pure whole cinna- 
mon and cassia, from which the following are taken: 



as — 
55 






IB o 



.0.^ 
<' 



Ceylon cinnamon, i 5-4° 

2 7-43 

Cassia buds 

Cassia bark (4 samples) : 

Maximum 

Minimum 



4-79 



17-45 
9-32 



4.55 
3-40 

5-58 

8.23 
2.48 



.82 
3-59 



3-51 



1.66 

1.58 
S-21 

2-38 
-74 



33-08' 2.98 
25-63 3-80 
8.60 7.00 



26.29 
14-33 



4-55 
2.63 



51.28 
56.84' 
65-23! 

65-33 
48.65' 



.48 
.62 
[.12 

-73 
.42 



* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 221. 



426 



FOOD INSPECTION AND ANALYSIS. 



Winton, Ogden, and Mitchell's * results of analyses of whole samples 
of cinnamon, cassia, and cassia buds are thus summarized: 



Moisture. 



Ash. 



Total. 



Soluble 

in 
Water. 



Insoluble 
in HCl. 



Ether Extract. 



Volatile. 



Non- 
volatile. 



Ceylon cinnamon (6 samples) 

Maximum 

Minimum 

Average 

Cassia bark (20 samples): 

Maximum 

Minimum 

Average 

Cassia buds (2 samples): 

Average 



10.40 

7-79 
8.63 

II. 91 

6.53 
9.24 

7-93 



5-99 
4.16 

4.82 

6.20 
3.01 
4-73 

4.64 



2.71 
1.40 
1.87 

2.52 
0.71 
1.68 

2.88 



0.58 
0.02 
0.13 

2.42 
0.02 
0.56 

0.27 



1.62 
0.72 
1-39 

5-15 
0-93 
2.61 

3-88 



.68 

•35 
-44 

•13 
■32 



5-96 



Alcohol 
Extract. 


Reducing 

Matters 

by Acid 

Conversion, 

as Starch. 


Crude 
Fiber. 


Nitrogen, 
X6.25. 


13.60 


22.00 


38.48 


4.06 


9-97 


16.65 


34-38 


3-25 


12.21 


19.30 


36.20 


3-70 


16.74 


32.04 


28.80 


5-44 


4-57 


16.65 


17-03 


?,-?>'^ 


8.29 


23-32 


22.96 


4-34 


10.88 


10.71 


13-35 


7-53 



Total 
Nitrogen. 



Ceylon cinnamon (6 samples) : 

Maximum 

Minimum 

Average 

Cassia bark (20 samples): 

Maximum 

Minimum 

Average 

Cassia buds (2 samples): 

Average 



0.65 
0.52 
0-59 

0.87 

0-53 
0.69 



Structure of Powdered Cassia under the Microscope. — Fig. 84, 
from Moeller, shows various elements of cassia bark as veiwed microscop- 
ically, (i) shows in cross-section a portion of the cork and outer layer 
of the bark rind, with flat cells nearest the surface, having somewhat 
thick walls and reddish-brown contents, and, farther in, the cells s, with 
mucilaginous material. 

The stone cells of the intermediate layer of bark are shown at (2). 
Here the tendency of the stone cells is to be thicker on one side than on 
the other, as is plainly shown. (3) represents the structure of the inner 
•layer of the bark, showing bast fibers h cut across, and more of the so- 
called mucilaginous cells 5 of large size, which normally contain the 
ethereal or volatile oil. The starch granules (4) are contained in great 
abundance in the polygonal cells of the parenchyma of the intermediate 



* Twenty-second Annual Report Conn. Exp. Sta., 1898, pp. 204, 205. 



SPICES. 



427 



and inner bark layers. (6) represents a fragment of a bast fiber, which 
is often shown in cassia powder with connecting parenchyma. The 
stone-cells of the cork are shown in plan view at (7). Ver}- small, needle- 
like cr}'stals of oxalate of calcium are occasionally to be seen if looked for 
carefully. They occur in the parenchyma cells of the inner and inter- 
mediate layers of the bark. 

The microscopical structure of Ceylon cinnamon much resembles 
that of cassia. Cassia starch grains measure from 0.0132 to 0.0222 mm., 




Fig. 84, — Powdered Cassia under the Microscope. X125. (After Moeller.) 



being considerably larger and more abundant that those of true cinnamon. 
As a rule the bast fibers of cassia are larger, but shorter, than those of 
cinnamon, and provided with thicker walls. 

Figs. 203 and 204, PL XXI, show various phases of pure cassia bark as 
photographed from water-mounted specimens of the pow^der. Cassia 
starch somewhat resembles that of allspice, but it is not as a rule found 
in masses containing as many granules as does the allspice starch. Ver\' 
commonly two or three of the starch granules are arranged together in 



423 FOOD INSPECTION AND ANALYSIS. 

such a manner that at first sight they appear to form a single large granule, 
but on more careful examination are seen to be two- and three -lobed, 
consisting of several smaller grains. Stone cells, which are ver^- abundant 
in the powdered cassia, do not happen to be included to any extent in the 
photographed fields. Cassia stone cells are generally more oblong than 
those of allspice, and are more often brown in color, while the allspice 
stone cells are generally colorless. 

A distinctive feature of powdered cassia consists in the long, amber- 
colored wood fibers, some distributed in bundles, and others arranged 
singly. These are very clearly shown in Figs. 204 and 205. 

Yellow patches of cellular tissue with starch grains interspersed, 
among them are very abundant in the powder. 

Adulteration of Cinnamon and Cassia. — The U. S. standards are 
as follows: Total ash not to exceed 8%; sand not to exceed 2%. 

The commonest adulterants are cereal products and foreign bark. 
Besides these, the writer has found, in samples sold in Massachusetts, 
leguminous starches, pea hulls, nutshells, turmeric, pepper, olive stones, 
ginger, mustard, and sawdust. Much of the China cassia when imported 
contains an inexcusably large amount of dirt. In one sample Winton, 
Ogden, and Mitchell found over 15% of sand. 

Ground Bark of the Common Trees, especially that of the elm, 
resembles in physical appearance ground cassia, and is to be looked 
for as an adulterant. Fig. 265, PL XXXVII, shows the appearance of 
ground elm bark. The fibers of cassia bark have starch granules as a 
rule interposed among them, while the foreign bark, usually of a much 
coarser texture, shows no starch connected with its structure. 

Fig. 206, PI. XXII, shows a water-mounted specimen of adulterated 
cassia powder, chosen from samples purchased in the Massachusetts 
market. Nothing but the adulterant (a foreign bark) shows in the field. 
The tissue is loose and considerably coarser than that of cassia bark. 

PEPPER. 

Nature and Composition. — Pepper is the dried berry of the pepper 
plant {Piper ?iigrum), a climbing shrub belonging to the family Pipe- 
racece, native to the East Indies, but cultivated in many tropical countries. 
The height of the pepper plant is from twelve to twenty feet. When 
the fruit begins to turn red, it is gathered and then dried, by which process 
it turns black and shrivels up, forming the black ' peppercorns of com- 
merce. They are spherical single-seeded berries, aboiit 5 mm. in diam- 



SPICES. 



429 



■eter, covered with a brownish-gray epicarp, and having on the under 
side the remains of a short stem. At the top of the berry is an indistinct 
trace of a style, and of a lobed stigma. 

Varieties of black pepper are named from the localities in which they 
are grown or from which they are shipped, as Singapore, Lampong, 
Sumatra, Tellichcry, Malabar, Acheen, Penang, Alleppi, Trang, Man- 
galore, etc. 

White pepper is obtained by decorticating the fully ripened black 
peppercorns, or removing the dark skin. This is accomplished by mac- 
erating them in water to loosen the skin, which is then removed readily 
by drying and rubbing between the hands. White whole pepper grains 
are grayish white, and a trifle larger than the black pepper berries. They 
are nearly spherical in shape, and have a number of hght-colored lines 
that, like meridians, run from top to bottom. The common varieties 
are Siam, Singapore and Penang, the latter being coated with lime. 

The pungent taste of pepper is due in great part to its essential oil, 
a hydrocarbon of the formula CioHig, present in amounts varying from 
0.5 to 1.7 per cent. Pepper oil contains phcUandrenc and a terpene. 

Other important constituents of pepper are piperidine, and the crys- 
talline base piper in, C17H19NO3, insoluble in water, but soluble in ether, 
and in alcohol. Starch is present in pepper to a large extent. 

Burcker gives the following average percentage composition of black 
and white pepper: 



Black pepper . 
White pepper. 





aj 




C I- 





.2-0! 


•d 
G 







u 


M^ 




f^ d 


r.'^ 




_2 

13 



^ 

^ 


|l 


OS 






4-57 


12.45 


12.50 


11.98 


1.36 


6.85 


42.90 


1.80 


6.08 


13-56 


II. 12 


0.94 


7. II 


56.04 



a 3 

o o 

V u 
bo u 



7-39 
3-35 



Richardson's * analyses of three samples of whole black and two 
samples of whole white pepper, all pure, are as follows: 



Water. 



Ash. 



Volatile 
Oil. 



Piperin 

and 
Resin. 



Alcohol 
Extract. 



Starch 
(Acid Con- 
version) , 



Black pepper: West coast. 

Acheen. 

Singapore. , 

White pepper: West coast. 
Singapore . 



8.91 
8.29 
9-83 
9-85 
10.60 



4.04 
4.70 

3-70 
1. 41 

1-34 



.70 
1.69 
1.60 

•57 
1.26 



7.29 
7.72 

7-15 
7.24 
7.76 



6.06 

5-74 

2.57 



36-52 
37-50 
37-30 
40.61 
43- 10 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 13, part 2, p. 206. 



43^ 



FOOD INSPECTION AND ANALYSIS. 



Undeter- 
mined. 



Crude 
Fiber. 



Albumin- 
oids. 



Total 
NX6.2S. 



Total N. 



Black pepper: West coast 
Achecn. . . 
Singapore . 

White pepper: West coast 
Singapore , 



24.62 
13.64 
17.66 

23.28 
19-55 



10.23 
10.02 
10.02 

4.20 



7.6Q 
10.38 
10.00 

9-31 
9.62 



Q.81 
12.60 
12.08 
11.48 
II .90 



1-57 
2.02 

1-93 
1.83 
1.90 



Richardson gives the following variations in the constituents of pure 
pepper : 





Black. 


White. 


Water 


8.0 to 1 1.0 
2.75 to 5.0 
.50 to 1.75 
7.0 to 8.0 
32.0 to 38.0 
8.0 to II .0 
7.0 to 12.0 


8.0 to II. 
1.0 to 2.0 
.50 to T.75 
7.0 to 8.0 
40.0 to 44.0 
4. II to 8.0 
8.0 to 10. 


Ash 


Volatile oil 


Pij)cTin and resin 


Starch 

Crude fiber 


Albuminoids 



McGill's * analyses of six samples of whole black, and five samples 
of whole white pepper, all genuine, are thus summarized: 





Moisture, 
etc., Lost 
at 100° C. 


Ash. 






Soluble 
in Hot 
Water. 


Insoluble 
in Water. 


Total. 


Insoluble 
in Hydro- 
chloric 
Acid. 


Sand 
Expressed 
as Per 
Cent of 
Total 
Ash. 


Alcohol 
Extract. 


Black: Maximum 

Minimum 

Mean 


14.10 
10.62 
12.03 
13.00 
11.30 
12.34 


2.64 
2.07 
2.41 
0.72 
0.14 
0.54 


3.06 
1.46 
2.05 
3 -04 
1-50 
2.46 


5.16 
3-98 
4-47 
3-65 
1.64 
3.00 


1.08 
.06 
0.36 
0.88 
0.26 
0-55 


21 

2 

8 
42 

9 

21 


9.06 
8.28 
8.71 
8.92 
7.00 
7-73 


White : Maximum 

Minimum 

Mean 





Winton, Ogden, and Mitchell's, and Winton and Bailey's f analyses 
of whole black pepper and whole white pepper, rc] resenting the leading 
varieties imported into the United States, also of ];epper shells and long 
pepper, are summarized in the following table: 



* Canada Inl. Rev. Dept. Bui. 20, 1890. 

t An. Rep. Conn. Exp. Sta., 1898, pp. 198-199; 



1903, pp. 158-164. 



SPICES. 



431 



^JI}B]OA-uo^J nj 



OOOOOOOCO 



M tT 0< r^ '^T to w U-, Oi "^ 
fj r^ « M 5ri ^l 50 "-i O n 



l^oi 



<^« O "< M ro'CO^ 



MCIC«MQil'<-.iaiC»CTn 



■SZ-9X 
'jDBjjxg Jama ui 
^J SS3J 'xiaSojjisj I^jox 



■-" 0000 OvM'~'Ci*3 



q q o 00 ■^ ""-T oq w re 

« « d 0»JC5 ■*« 



•jaqij 3pnJ3 



-i- o t^ «^ O 0> 'C ^C <*> 



i-i M CI r*^ -r 



•asBjsBiQ Xq qoJB^g 



►1 00 M O to »-< 



f^ O O i^' 



*^T r^ *^ w% 

\o to fi loto «o "Q •" 



•qsjBis SB 
'uoisaaAuo^ PPV 
Xq sja^iBj^ 3uiDnp3-jj 



lil >H l-> t~. ' 



ri — O yi r— 



•j3BJixg loqoajv 



0000 OvO ONO»-iOoCi 



c0>00 n'C^to O O t^ 
00 ■*rOf<"/'0'~<to rcOvO 



•ajpBjOA-uo"^ 



t^ooo ozc c?:ito'>: 



-f -f M ^Tto 

CI OC vO "V3-. ^J 


01 


0^ 


-r - 
^ 


•^ r~ ■C ir^ to 


to 


-r 


coo 



■aipBiOA 



q 00 M q "i-vq ®i to ®i 

mO'-i -<>-"-" ®iO'~< 



O O O O CS Ci o 



"lOH a? aiqniosui 



OO-'O-Hw'-iC;!^ 



w 00 t/->OOC) O COM 

O O ■- h- ^ O '^ r^»o c* 
ddddocio'i-f'd 



■jaiBjvi^ ui aiqnjog 



CICICIMMcogO*^ 



r- cox i^.p Co ?^ o eo o 
•^ CO CO o Qc ^ "<^ CI CI CI 

d d d dooo '^'' "* 



l^ox 



rO-l-^S >Ol/^t/^^QrJU5 



O cot^-rto'30f~ Mtty~, CO 

q roTt-oqCiOt^ onci q> 

Mn>-(Ci^'M>|i>..,,^d''^ 



•ajnjsio}^ 



CI »-( ^ CI CI ,_,<^^';^>^ 



~-T ®} '50 O O C^ 



•S3|dxues JO J3qain|i{ 



ir-, CI -r « CO fl o 



N n CO CO o 






fc sic < 3: U r 
c '' 5 ^ ^ ^ •- 

3:= £ ^ ± ^ j; 

^ h J < < < < 



<! ■^ 


t< 




5=; 







^ ^ <: S ,< 



i C -^ ■:Z i < 






432 



FOOD INSPECTION /1ND /INALYSIS. 



The following tabic summarizes the results of full analyses of pepper 
and pepper shells recently mack by Doolittle :* 



No. of 
Samples. 



No. of 
Varieties. 



Mois- 
ture. 





Ash. 




Total. 


Insoluble 
in HCl. 


Soluble in 
Water. 


8.04t 

3-43 

4-99 


2-59t 

0.05 

0.58 


3-32 
1-65 
2.49 


4.28 
0.86 
1.69 


0.86 
0.05 
0.19 


1. 16 

O.T2 
0-34 


14.39 
6.12 


5-92 
0.45 


4-39 
1.72 


28.81 


22.90 


4.66 


7.82 


0.79 


I-.53 



Starch by 
Diastase 

Method. 



Black pepper: 

Maximum. 

Minimum . 

Average . . . 
White pepper; 

Ma.\imum. 

Minimum. 

Average , . . 
Long pepper: 

Maximum. 

Minimum. 
Pepper shells: 

Maximum. 

Minimum . 



45 



11.96 
8.09 
9-54 

13-34 
8.04 
9.87 

10.13 
8.43 

II. 01 
7.00 



41-75 



25 
36. 

63- 
48. 

54- 

45 
28 



09 
69 

55 
88 

37 

.87 
43 

.70 
.28 



Ether Extract. 



Volatile. 



Non-vola- 
tile. 



Crude 
Fiber. 



Nitrogen. 



Total. 



In Non- 
volatile 
Ether 
Extract. 



Total N 
less N in 
non-vola- 
tile Ether 
Extract 
X6.25. 



Black pepper: 

Maximum. . 

Minimum . . 

Average 

White pepper: 

Maximum. . 

Minimum . . 

Average 

Long pepper: 

Maximum. . 

Minimum . . 
Pepper shells: 

Maximum., 

Minimum . , 



0.85 
1.30 

1.66 
0.78 
1. 17 



0.79 



0.89 



10.44 
6.60 
7.67 

7.26 

5-65 
6.46 

7-53 
5-71 

4-67 
1-51 



18.89 



7-65 

O.IO 

4-17 

10.01 

7.19 

28.22 
21.06 



2.38 

1.86 
2. II 

2.14 
1.85 
1-97 

2.04 
2.13 

1.82 
1.72 



0-4S 
0.25 
0.31 

0-34 
0.24 
0.30 

0.22 
0.18 



13.12 

9-25 
11.20 

11.56 

9.69 

10.44 

12.06 
".37 

11.25 
10.00 



t Two samples of Acheen C pepper had a total ash of 8.00% and 8.04%, with ' 'ash insoluble in 
HCl" of 2.sg% and 2.40% respectively. Eliminating these two samples, which were evidently 
.abnormally high in sand and dirt, the highest total ash of the remaining 43 samples was 7.00%, 
while the highest ash insoluble in HCl was 1.80%. 

Determination of Nitrogen in Black and White Pepper. — Winton, 
Ogden, and Mitchell have shown that the Kjeldahl and Gunning methods 
are inapplicable in the case of pepper, owing to the presence of piperin, 
but that the Gunning- Arnold f method gives accurate results. In accord- 
ance with this method, i gram of the sample is mixed with a gram each of 
copper sulphate and red oxide of mercury, about i6 grams of potassium 

* Mich. Dairy and Food Comm. Bui. 94. 
t Zeits. anal. Chem., 31, 1892, p. 525. 



SPICES. ^^^ 

sulphate, and 25 cc. of sulphuric acid in a Kjeldahl flask, for both diges- 
tion and distillation, of about 600-cc. capacity. The heating is conducted 
in the usual manner, beginning with a gentle heat till the frothing ceases, 
and gradually increasing the temperature till the mixture boils. The 
boiling is continued for three or four hours, after which the flask is 
cooled, and to it are added 300 cc. of water, 50 cc. of potassium sulphide 
solution,* and enough of a saturated solution of sodium hydroxide to 
render the reaction alkaline. 

The flask is then connected to the condenser, and the distillation con- 
ducted as in the Gunning method fp. 69), using zinc dust to prevent 
bumping, receiving the distillate into standard acid, and titrating against 
standard alkali. 

Nitrogen Determination in the Ether Extract.!— Ten grams- of the 
sample are extracted with absolute ether for twenty hours in a con- 
tinuous-extraction apparatus, the extract being collected in a tared Kjel- 
dahl extraction- and distillation-flask, the same as used in the preceding 
section. The ether is then evaporated off, the residue dried to constant 
-weight at 110° C. and its weight ascertained. The nitrogen is then 
■determined in the ether extract by the Gunning- Arnold method. 

Determination of Piperin.J — Fifty grams of the sample are thoroughly 
exhausted with hot alcohol, and the alcohol extract evaporated to dry- 
ness. The dry residue is then treated w^ith a solution of potassium 
hydroxide, and washed upon a filter. The residue is washed several 
times with the caustic alkali, which dissolves the resinous matters, and 
afterwards with water. It is then dissolved in alcohol, from which crj^stals 
of crude piperin separate on evaporation. These are redissolved in 
alcohol, and precipitated by the addition of water. The crystalline pre- 
cipitate is collected on a tared filter, washed with wacer, dried, and 
weighed. 

Piperin may be roughly estimated by multiplying the nitrogen in 
the ether extract by the factor 20.36. 

The amount of piperin \aries considerably, ranging in black pepper 
from 4 to 9 per cent. 

Microscopical Characteristics of Ground Pepper. — Moeller's repre- 
sentation of powdered black pepper shows what should be looked for 
under the microscope with the best conditions (Fig. 85). The shell of 
the peppercorn, a cross-section of which is shown at (i), consists of the 

* Forty grams K,S in i liter or water. 

t Method of Winton, Ogden and Mitchell. 

J Villiers et Collin, Substances Alimentaires, p. 371. 



434 



FOOD INSPECTION ^ND ^N^ LYSIS. 








epidermis, a, under which is a thin layer of brown parenchyma, c, 

while below this layer is shown the most characteristic portion of 

the pepper shell, viz.: the thickened, 
colored, stone cells, b. These are as a 
rule inclined to be rectangular rather 
than rounded. At d is shown a bit of 
the colorless parenchyma of the fruit 
itself. 

(2), (3), and (4) show a cross-section 
of the outer part of the berry, (2) 
representing the inner stone-cell layer, 
a single row of horseshoe-like cells, 
(3) the thin seed coat, and (4) the white 
perisperm, with its large cells. Here and 
there through the perisperm certain yellow 
contents are visible, consisting largely of 
resinous matter. A dark resin cell is 
shown at (4). The ethereal oil, starch, 
and piperin are found in this part of 
the berr}^ 
(5) shows in plan view the mostly rectangular stone cells of the 

pepper shell, resting upon the epidermis (6), Groups of stone cells 

are frequently thus found with portions of the epidermis. 

The inner rounded, or cup-shaped cells are shown in plan view at 

(7) and the seed skin at (8), masses of starch and separate starch granules 

are shown at (9), and crystals of piperin at (10). 

The bast-parenchyma of the pepper stem is shown at (11), 

pieces of which are commonly found in powdered pepper, and (12) 

shows a fragment of one of the many-celled hairs which grow on the 

stem. 

The rounded cup cells (7) are readily distinguished from the more 

rectangular stone cells (5). The walls of the cup cells are nearly always 

colorless, and the cells themselves empty.* 

A water-mounted specimen of finely ground, black pepper, when 

viewed microscopically, shows most of the elements above described, at 

least in fragmentar}^ form, though, in the case of the coarser particles. 



Fig. 85. — Powdered Black Pepper 
under the Microscope. X 125. 
(After Moeller.) 



* The harder portions of the pepper, especially of the shell, are best examined by soak- 
ing for at least twenty-four hours in chloral hydrate, and mounting in this reagent on the 
slide. 



SPICES. 435 

by no means as clearly as by the use of chloral hydrate. Large polyg- 
onal masses of starch appear grouped as photographed in Fig. 256, PI. 
XXXI\', if not rubbed out too fine under the cover-glass. Starch, in- 
deed, L5 the most conspicuous element of pepper, being distributed more 
or less evenly throughout the mass. The powder may, however, be so 
finely reduced by abrasion under the cover-glass as to break up these 
starch masses wholly or in part, so that the granules may appear in much 
smaller groups or even singly. Fig. 255 shows such a field under a 
higher magnification. The indi\'idual granules of pepper starch average 
0.003 ^^- "1 diameter. 

Besides the starch, and next to it the most numerous, one finds in the 
water-mounted black-pepper specimen many of the dark-yellow, thick- 
walled stone ceUs, p>atches of the colored parenchyma, and epidermis of 
the shell. Other elements of the perisperm, besides the starch, are 
seen in fragments, such as bits of resin, small droplets of oil, pieces of 
stems, and occasionally the needle-shaped crystals of piperin. Some 
of the rounded, cup-shaped cells are also usually found. 

WTiite pepper contains, of course, the same elements, but -w-ithout 
the deeply colored stone cells and other characteristics of the shell, 
which has been removed from it. 

Adulteration of Pepper. — The following U. S. standards for pepper 
have been adopted : For white pepper, non- volatile ether extract should 
not to be less than 6^ ; starch should not be less than ^0% by the diastase 
method; total ash should not be more than 4%; ash insoluble in hydro- 
chloric acid should not exceed o.^^l; crude fiber should not exceed 5-^. 
One hundred parts of the non-volatile ether extract should contain not 
less than 4 parts of nitrogen. For black pepper, which should be free 
from added pepper shells, pepper dust, and other pepper by-products, 
non-volatile ether extract should not be less than 6%; starch by the 
diastase method should not be less than 2^%; total ash should not exceed 
7*^; ; and crude fiber should not exceed 15 5^. One hundred parts of the 
non-volatile ether extract should contain not less than 3.25 parts of 
nitrogen. The adulterants used in ground pepper are many and varied- 
Pepper Shells, which have been removed from the v%'hite pepper of 
cortmierce, are not infrequently ground and added to the cheaper grades 
of black pepper, ^^^len a sample of black pepper is sho\s-n by the micro- 
scope to contain more sheUs in proportion to the other elements than 
could be possible in a ground whole berr>-, added sheUs are indicated. 



436 FOOD INSPECTION AND ANALYSIS. 

The analyst should, for comparison, grind in a mortar single berries of 
various grades, and familiarize himself with the appearance of the ground 
powder under the microscope, when the maximum amount of shells 
possible under natural conditions are present, noting especially the appar- 
ent number of stone cells of the outer coating. The familiar title of P. D. 
(pepper dust) originally given to ground pepper shells, slems, and "sweep- 
ings " is now applied in the trade not only to almost any cheap and appro- 
priate material for admixture with pepper, but also, in a broader sense, 
to ground powder suitable as an adulterant for any spice. 

The presence of pepper shells is indicated by an excess of ash, sand, 
and crude fiber, and a deficiency of starch. 

Hilger and Bauer, also Hanus and Bien, advocate the determination 
of pentosans as a means of detecting pepper shells. 

Ground Olive-stones constitute one of the most commonly found foreign 
materials used as an adulterant of pepper. The powder, sometimes 
called "poivrette," is very like white pepper in appearance, is wholly 
inert in taste, and thus forms an admirable adulterant. While best 
detected by their characteristic appearance under the microscope, the 
presence of ground olive stones may be shown by color tests with certain 
chemical reagents. 

Pabst has adopted for this purpose a test first suggested by Wurster 
for the detection of wood pulp in paper. The reagent is prepared as 
follows: In a porcelain capsule lo grams of commercial dimethyl anihn 
are mixed with 20 grams of pure concentrated hydrochloric acid, and 
at least 100 grams of cracked ice are added. Then, while stirring, a 
solution of 8 grams of nitrite of soda in 100 cc. of water are added Httle by 
little, and the mixture allowed to remain for half an hour, after which 
30 or 40 cc. of hydrochloric acid are added, and 20 grams of tin-foil. 
The reduction is allowed to go on for half an hour, heating on the water- 
bath, if necessary. The tin is then precipitated by granulated zinc, the 
liquid is filtered, and the filtrate neutralized with carbonate of potassium 
or sodium to the point of forming a precipitate, the precipitate being 
dissolved by a few drops of acetic acid. Finally the volume is made up 
with water to 2 liters, adding, before doing so, 3 or 4 cc. of a concentrated 
solution of sodium bisulphite, to prevent oxidation. The reagent thus 
prepared will keep for several years in a brown, tightly stoppered bottle. 
If a pinch of pepper, which contains ground olive stones, be heated 
gently with a little of the above reagent in a test-tube, the stone cells 
of the adulterant will be colored a bright red brown, and the colored 
particles will be seen to settle to the bottom of the tube, after shaking, 



SPICES. 437 

more quickly than the rest of the powder. Or, if the whole is poured 
from the test-tube into a porcelain dish, the color is more marked. Pure 
popper is not colored under this treatment with the reagent. 

Jumeau uses for a color reagent 5 grams of iodine in 100 cc. of a mix- 
ture of equal parts of ether and alcohol. Enough of the finely ground 
pepper to be examined is placed in a porcelain capsule to cover the 
bottom of the dish, and sufficient iodine reagent is added to wet the entire 
mass, carefully avoiding excess. The thick paste is first mixed till homo- 
geneous, and then allowed to dry in the air, after which it is broken up 
by a pestle, and the powder examined, either under the microscope, or 
by the naked eye. With pure pepper, a more or less deep-brown color 
is produced uniformly through the powder, but if olive stones are present, 
particles of these are colored yellow. With the naked eye as small an 
admixture as 2% of olive stones can thus be detected. 

A solution of anilin acetate colors olive stones yellowish brown, 
while pure pepper appears grayish, or white. 

Under the microscope oHve stones are readily apparent, since the 
stone cells differ in size, form, and mode of grouping from those of pepper. 
Fig. 263, PI. XXXVI, is a photograph of a water-mounted specimen of 
olive stones. They are for the most part entirely devoid of color, being 
long and narrow. In shape and manner of grouping they much resemble 
cocoanut shells (p. 419), but are distinguished from the latter from their 
lack of color. 

Fig. 261 shows under low magnification a sample of pepper, bought 
on the market in Massachusetts, highly adulterated with olive stones. 
A large mass of the stone cells of the adulterant appears in the center of 
the field. Many of the stone cells are shown arranged end to end, so 
that what at first sight appear to be single, very long cells are in reality 
made up of several shorter ones. In ground olive stones one frequently 
finds, besides the stone cells, bits of the outer tegument of the seed, show- 
ing large cells with sinuous, rather thick walls; also bits of parenchyma, 
crossed frequently by fibro-vascular duct bundles. 

Buckwheat Products. — Both the hulls and the middlings have been 
added to black pepper, and the middlings to white pepper. The starch 
of buckwheat possesses the added advantage, from the point of view 
of the spice-grinder, that it somewhat resembles pepper starch in micro- 
scopical appearance, not only in the shape of the starch granules, but also 
in the manner of grouping into masses. Compare Figs. 128 and 129, 
Plates II and IJI, showing buckwheat starch, with Figs. 255 and 256, 
PI. XXXIV, respectively, showing pepper starch made under similar 



438 



I'oou iNsrLcrioN and /ISALYSIS. 



conditions of magni (kill ion, etc. Tlu' starch granules and masses arc 
coarser in the case of buckwheat than of pepper. 

Fig. 260, PI, XXXV, shows a |)hotogra])h of a i)ej)per sample adulterated 
with buckwheat, masses of both starches appearing in the same held. 

Other Adulterants found in Massachusetts samples of ])e|)|)er have 
been wheat and corn products, nutshells, cayenne, charcoal, turmeric, rice, 
.sand, and sawdust. Charred cocoanut shells were at one lime extensively 
used (see pp. 419 and 420). 

Long Pepper, according lo iMiglish analysts, has been used to a con- 
siderable extent as an adulterant, 'i'liis is the fruit of the Chavka Rox- 
burghi't, a wild i)laiit growing in India on the banks of rivers. The fruit, 
a.s its name implies, is long and cylindrical, while of about the same diam- 
eter as the spherical true pep])ercorns. Long pepper contains, as a rule, 
less than half the amount of piperin that true pe|)per does, and rather more 
star(h than bhuk pepper. Its taste is much less j)ungent than that of 
true pepper. 

l"'roni its uietliod of growth, long pe|)per is found with consideraljle 
dirt and sand adiiering to the outer surface of the (h-ied grains. This 
is ilue lo du' fail that the fruil often trails on the ground, and in gather- 
ing it \\\(' nali\('S arc not particular about icmoving the adhering soil. 
The surface of the fruit grains being very rough and irregular, much 
of the dirt remains dried tlu'reon. The presence of long pepi)er liius 
niatei-iatly increases the ash. 

Long pepper possesses a very disagreeal)le, but ])eculiar odor, devel- 
oped more especially when slightly warmi-d. l'\)r this reason, if for 
no other, it is not an ideal adulterant, since i)epper containing it would 
not be j^alatable with warm food. At the j)re.sent time it costs more than 
black |)epper, and is used chielly in mixed whole spices for pickles. 

Brown gives the foHowing analyses of samples of long pei)per: 



Ttital 

Asli. 



8.91 
8.98 
0.61 



Sand and 
Asli Insol- 

uIjIc in 
Ilydroclilo- 

ric Acid. 



1.2 
I.I 

1-5 



Starcli and 
Matters 
Converti- 
ble into 
KuRar. 



44.04 

49-34 
44.61 



Alljumin- 

(lus Matte 

Soluble In 

Alkali. 



15-47 
17.4-' 

T5-51 



15-7 
10.5 



Alroh.ilie 
Extract. 



7-7 
7-6 

^0-5 



IJxtrait. 



5-5 

4-g 

8.6 



Total 

NilroKcn. 



2-.3 



According to Brown and Heisch, the granules of long pepper starch 
under the microscope arc larger than those of true ])epper, and more 
angular. Stokes,* however, finds no such marked dilTerence in the size 



* Analyst, XIII, p. 109. 



SPICES. 439 

of starch granules and his experience is shared by the writer. When 
the two specimens (long and true pepper) are viewed side by side in 
water mounts under the microscope, the average size of the long pepper- 
starch grains is a trifle larger than those oi true pepjjer, though, unless 
compared directly, the difference is not readily apparent. Stokes sug- 
gests a method of distinguishing the two by polarized light. With crossed 
Nicols, so that a dark field is given, and with the specimen mounted 
in glycerin, true pepper starch shows an evenly dark ai>pearance, using 
i\ low power, while with long pepper a "ghostly white" image is shown. 
Long jK'iJper, when present in true pepper jxjwder, may generally be 
rcnrlered apparent by the development of the characteristic odor on 
heating. Bits of fluffy fiber from the calkin of the long pjepper will always be 
found in the ground powder, and will be apparent under the magnifying-glass. 
Microscopic examination of the crude fiber discloses the highly char- 
acteristic, large, beaded cells of the endocarp, also elements of the spindle. 

RED PEPPER. 

Nature and Composition. — According to the U. S, Standards red 
pepper is the red, dried, ripe fruit of any species of Capsicum, a genus of 
the nightshade family (Solanacea;}, imligenous to the American tropics, 
but now cultivated in nearly all warm and temperate countries, and is of 
two distinct kinds: cayenne pepper or cayenne, the dried ripe fruit of 
C. frutescens, C. haccatum, or some other small fruited species of Capsicum, 
and paprika, the dried rii>e fruit of C. annuum, or some other large-fruited 
species of the genus, excluding seeds and stems. 

Cayenne is characterized by its extreme pungency and the small size 
of the pods, which seldom exceed 2 cm. in length. The lea<^ling commercial 
varieties are Zanzibar and Japan, the latter being the more brilliant in color. 

"Capsicums'^ or ''Bombay Chillies'' are low grarle peppers of a 
brown color, with ix)ds 2 to 3 cm. long, which now are said to come from 
the vicinity of the river Niger in Africa. 

Paprkia is a variety of C. annuum grown in Hungary. The powder is 
of a deefj red color and has a sweetish, mildly pungent flavor. 

Pimienlo is a large-fruited pepper grown in Sj^ain. The succulent 
pcricarj^ is much used for stuffmg olives while the dried pod is ground as 
a spice, often being substituted for the more valuable Hungarian varieties. 
The kitchen garden peppers, of which over thirty varieties are cultivated 
in the Unite<i States, also belong to the species C. annuum. 

The capsicum plant has solitary flowers, with a five-cleft corolla, and 
the fruit is of an elongated, conical form. The surface of the fresh fruit 



44° 



FOOD INSI'liCnON /INI) ANALYSIS. 



is smooth and very red, but it loses some of its brilliance in drying, and' 
becomes shriveled. The pericarp is thin and tough, and at its base is 
a five-lobed calyx, greenish brown in color, terminating in a thick stem. 
The fruit proper is divided intcj two or three cells, which are sej;arate 
and distinct at the lower portion, but which unite and form one at the 
top. The cells inclose a large number of yellow, wrinkled, kidney- 
shaj)cd seeds, containing a fleshy endosperm, anrl a curved embryo. 

Red pej)j)er contains a fixed, bland oil, found in both pod and seed, but 
more abundantly in the latter, considerable resinous and mucilaginous 
material, a red coloring matter confmed to the pod, and the active principle 
capsicin, a crystalline alk:!,loi<l, to which much of the pungency is due. 
The capsicin is present in both seeds and pod, but is more abundant in 
the latter, where it is dissolved in the oil. 

Capsicin may be isolated, according to Thresh, l^y extracting pow- 
dered cayenne with petroleum ether, mixing the red residue left on 
evaporating off the solvent with two or three times its weight of oil of 
;dmonds, and exhausting the mixture with alcohol. On evaporating 
the alcohol extract, the capsicin crystallizes out in narnnv, thin plates, 
very soluble in alcohol, but insoluble in water. They volatilize at ioo°, 
and condense in small drops. 

The red coloring matter is soluble in ether, petroleum ether, carbon 
bisulphide, and chloroform, but sparingly soluble in alcohol. 

Analyses of Cayenne. —Richardson * gives the following data of analyses 
of two pure samples of cayenne: 





u 

13 


< 


O 
y. 




■a 


.S 







c 
2 


A 


2-35 
5-74 


9 . o6 
5-24 


O.I2 

i.5« 


26.99 
17.90 


16.88 
18.10 


13-13 
11.20 


41.47 
40.24 


100 
100 


2.10 


B 


1.70 





Maximum and minimum data of ash and non-volatile ether extract 
of fourteen samples of cayenne, sold in sealed packages in Connecticut, 
and analyzed by Winton and Mitchell are as follows : f 



Ash. 


Non-volatile 
Ether Extract. 


Maximum 7 . i& 


19.14 
15-59 


Minimum 5-88 





* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 211. 
•j" An. Rep. Conn. Exp. Sta., 1898, p. 175. 



SHCHS. 



441 



Winton, Ogdcn, and Mitchell * analyzer] eight samples of whole 
chillies, rejjresenting three varieties, namely Zanzibar, Ja[>an,anf] Bombay, 
the summarizefl results being as follcAvs: 





Moisture. 




Ash. 




Ether Extract. 




Total 


Soluhile in 
Water. 


Insoluble 
in HQ. 


Volatile. 


Nr/n-vf)la- 
tile. 


Maximum 


7.08 1 5.96 
•2.67 e riR 


4.93 
3-30 
3.98 


0.23 
0.05 
0-15 


2-57 
0-73 
1-35 


2T.8l 

17.17 
20. 15 


Minimum 


Average 


5-73 


5-43 



Alcohol 
Extract. 



Rcducinfr 
Matters as 

Starch , 
Acid Om- 

versifjn. 



Starch by 
Diastase 
Method. 



Crude 
I'iljer. 



Nitrogen, j Total 
X6.2S. Nitro>{en. 



Maximum. 
Minimum . 
Average. . , 



27.61 
21.52 
24.35 



9.31 
7-15 
8-47 



1.46 
0.80 
1. 01 



24.91 
20-35 

22.35 



14.63 
13-31 
13-^^7 



•34 
■13 
.18 



The percentages of " starch by the diastase methof] " given in the 
dbove table represent errors of the process as neither cayenne or j^aj^rika 
contain an appreciable amount of starch. 

Analyses of Paprika and Pimiento. — Doolittle and Cjgrjen f have made 
exhau.stive analyses of known samples of Hungarian and Spanish red 
pepper, including determinations of non-volatile ether extract, and iodine 
number of this extract, which are of esf^ecial value in detecting arirjed 
oil. A summary of their results is given on j;age 442. 

Microscopical Structure of Red Pepper. — Fig. 86, from Moeller, 
shows the ap,oearance under the microscoj^e of various elements of powdered 
paprika, dj is a sectional view through the outer portion of the fruit 
shell or pod, showing the epidermis a, and beneath this the collenchyma 
layer. The inner epidermis is shown at (2}, with its cells thick-walled 
in places, and inclosing brilliant, red oil drops of coloring matter, (t^) 
represents the outer, and (4; and (5^ the inner epidermis in fjlan view. 
The outer epidermis of cayenne, which is the element of chief value in 
distinguishing this from paprika, is .shown at (6j. 

A cross-section through the seed .shell is shown at Cy), a being the 
epidermis of the seed, h the parenchyma layer directly beneath, and c 
the tissues of the endosj^erm. (8) shows in plan view the pecuhar st-ed 



* Am. Rep. Conn. Exp. Sta., 1898, pp. 200-201. 
t Jour. Am. Chem. Soc, 30, 1908, p. 1481. 



442 



FOOD INSPECTION AND ANALYSIS. 







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1 



SHICES. 



443 



epidermis, the appearance of which Moeller compares with that of 
intestines. At ig) is sho\NTi one of the isolated cells of this epidermis 
more highly magnified, while (loj shows the epidermis of the calyx. 

Figs. 211 and 212, PI. XXIII, show photomicrographs of powdered 
cayenne. In Fig. 211 is shown a large bit of the outer epidermis of the 
fruit pod, while in Fig. 212 appears a smaller portion of this same kind 
of epidermis, and next to this the characteristic .skin of the seed shell, with 
its striking markings suggestive of the convolutions of the intestines. 
Yellow or yellowish-red droplets of oily coloring matter are distributed 
through the field. Starch grains are absent. 




Fig. 86. — Po^tiered Cayenne under the Microscope. X125. TAfter Moeller.) 

Adulteration of Red Pepper. — The U. S. standards for cayenne are the 
following: Xon- volatile ether extract should be not less than 15%; total 
ash should not exceed 6. 5 S^: ash insoluble in hydrochloric acid should 
not exceed 0.5%; starch by the diastase method should not exceed 
1.5^. and crude fiber should not exceed 289c • 



444 FOOD INSPECTION AND ANALYSIS. 

The most common adulterants ot cayenne are the starches of the 
cereal grains, corn and wheat. Ground p)ilot bread and crackers are 
especially common. Besides these the writer has found in the routine 
examination of cayenne samples in Massachusetts, ginger, nutshells, 
turmeric, rice, gypsum, buckwheat, ohve stones, mustard hulls, ground 
redwood, red ocher, and coal-tar dyes. Fig. 213, PI. XXIV, shows a 
sample adulterated with wheat, corn, and cocoanut shells. 

Mineral Adulterants, such as gypsum, and red ocher and other pigments, 
are all to be looked for in the ash by methods of qualitative analysis. 
An abnormally high ash is suggestive of adulteration. According to 
Vedrodi, the ash of genuine cayenne should not exceed 5.96. The presence 
of red ocher is rendered apparent by the high content of iron. 

Salts of lead and mercury are rarely if ever now used for color. 

Ground Redwood. — Numerous varieties of redwood are commonly 
used to intensify the color of cayenne, especially when otherwise highly 
adulterated with colorless materials, such as the starches. The redwood 
is sometimes used alone, and sometimes in mixture w^ith turmeric. Both 
redwood and turmeric are readily recognized under the microscope. 

Fig. 214, PI. XXIV, shows a cayenne sample adulterated with corn 
starch and red sandalwood, a mass of the latter filling the center of the 
field. The wood fibers of the dyestuff, even when finely ground, are 
ver}' striking under the microscope, showing a brick-red color. 

Detection of Coal-tar and Vegetable Colors. — Oil-soluble coal-tar 
and vegetable colors may be tested for in cayenne and paprika by an 
adaptation of Martin's butter-color method, shaking the ether extract 
of the sample with the alcohol and carbon bisulphide mixture, page 535. 
The carbon bisulphide dissolves the oil and natural color, while the over- 
lying alcohol layer holds in solution many of the artificial coloring matters 
that may be employed. 

The natural colors of cayenne and paprika are sparingly soluble in 
alcohol, but readily soluble in carbon bisulphide. The separated alcohol 
is examined for colors by methods given elsewhere. 

Tests for coal-tar dyes should also be made by Sostegni and Carpen- 
tieri's, or Arata's method (p. 793). 

Szigeti * treats the suspected sample with water acidified with acetic 
acid, and boils in this solution a bit of wool, which, if carotin or a coal-tar 
dye be present, is colored red. If the color is carotin, it will be removed 

* Zeits. landw. Versuchs. Oesterreich, 5, 1902, pp. 1208, 1222. 



SPICES. 445 

from the wool by treatment with petroleum ether, or by heating at ioo° 
C. for some hours, but if a coal-tar dye, it will still remain fixed thereon. 

Detection of Added Oil in Paprika. — The color of paprika is often 
intensified by grinding with olive oil or some other oil. This form of 
adulteration is detected by determinations of non-volatile ether extract 
and iodine number of the extract. 

Doolittle and Ogden's results (page 442) indicate that paprika 
prepared from the pods after removal of the stems, seeds, and placentae 
should not contain more than 7.0% of non-volatile ether extract and the 
iodine number of this extract should not be less than 127, while that made 
from the whole pod should not contain over 12.00% of non-volatile ether 
extract, and the iodine number should not be less than 130. 

The method employed by Doolittle and Ogden consists in extracting 
2 grams of the material on a dried filter paper with anhydrous ether, 
collecting the washings in a tared, glass-stoppered flask, distilling to remove 
ether, and drying the residue for thirty minutes, or to constant weight, 
in a steam bath. Iodine number is determined in this non-volatile ether 
extract by the Hanus method (page 491). 

This method gives a lower percentage of non-volatile ether extract, and 
a higher iodine number than extraction in a continuous apparatus for 16 
hours. The latter method is open to the objection that, owing to the 
presence of slowly soluble resins, the results are appreciably affected by 
the rate of extraction. 

The following method gives concordant results, although somewhat 
different from those by the preceeding methods: Dry 4 grams of the 
material in a watch glass over sulphuric acid for 18 hours, place in a 
100 cc. flask, add anhydrous ether to the mark, and shake at five minute 
intervals for 30 minutes. Filter through a dry paper into a flask, keeping 
the funnel covered with a watch glass to prevent evaporation. Pipette 
off an aliquot of the filtrate equivalent to about 0.2 gram of extract, distil 
off the ether, dry, and determine iodine number as above described. 

GINGER. 

Nature and Composition. — Ginger as a spice is the ground root- 
stock of the Zingiber officinale, an annual herb of the family Zingi- 
beracece, growing to a height of from 3 to 4 feet. It is a native of India 
and China, but is cultivated quite extensively in tropical America, Africa, 
and Australia. 

The root is dug when the plant is a year old, and when the stem has 



446 



FOOD INSPECTION AND ANALYSIS 



withered. If the root, when freshly dug and scalded to prevent sprout- 
ing, is dried at once, it forms the so-called black ginger, of which Calcutta 
and African are the common varieties. When decorticated, the product 
is known in commerce as white ginger, the chief varieties being Jamaica, 
Cochin, and Japan. The best variety is Jamaica ginger. The scraped 
root is sometimes bleached to make it still whiter, or sprinkled with 
carbonate of lime. 

In commerce whole or black ginger appears in " hands " 4 to lo cm. 
long, and from 10 to 15 mm. in diameter. These usually have three or 
four various-sized, irregular branches, some short and thick, others 
elongated. The epidermis is gray or yellowish gray in color, more or 
less wrinkled, and beneath it is a reddish-brown layer. The inner portion 
of the dried root is white or yellowish. The root is hard, and of a com- 
l)act, horny structure. 

White or decorticated ginger appears in " hands " of smaller diameter 
than the black, and yields a lighter colored powder on grinding. Preserved 
ginger root is prepared by boiling the root in water, and curing with sugar 
or honey. Much of the preserved ginger comes from Canton. 

The distinguishing features of ginger are its large content of starch, 
its volatile oil, and its resinous matter. Inasmuch as the epidermis con- 
tains a large amount of pungent resin, it is easy to see how the peeled or 
decorticated variety is inferior. 

Oil of ginger is very aromatic, and of a greenish-yellow color. Its 
specific gravity ranges from 0.875 to 0.885. I^ ^^ sHghtly soluble in alco- 
hol. Of its composition little is known. 

Richardson's analyses in full of five samples of whole ginger-root are 
as follows: 





1-^ 


< 


|5 




u 


0^ 






1 

2 


Calcutta 


9.60 

9.41 

10.49 

11.00 

10. II 


7.02 
3-39 
3-44 
4-54 
5-58 


2.27 
1.84 
2.03 
1.89 
2-54 


4.58 
4.07 
2.29 

3-04 
2.69 


49-34 
53-33 
50-58 
49-34 
50-67 


7-45 
2.05 

4-74 
1.70 

7-65 


6.30 
7.00 
10. 8^ 
9.28 
9.10 


13-44 
18.91 

15-58 
19.21 
11.66 


1. 01 


Cochin 


1. 12 




1.74 
1.48 
1.46 


Bleached Jamaica, London 

" " American 



Summaries of Winton, Ogden, and Mitchell's analyses of eighteen 
samples of whole ginger, representing the common white and black 
varieties, as well as of two samples of exhausted ginger, are as follows: 



SPICES. 



447 



Ash. 



-^ 



Ether Extract. 



Ginger: Maximum ii-72| 

Minimum 8.71J 

Average 10.44 

Exhausted ginger from English ginger- j 

ale works 10.61 

Exhausted ginger from extract works . . 8.02 



9-35 
3.61 

5-27 



4.09 

1-73 
2.71 

0-59 
3-55 



2.29 
0.02 
0.44 

0.18 
1.50 



3-53 
0.20 
0.80 



3-09 
0.96 

1-97 

1. 61 
0-13 



Ginger: Maximum 6.58 

Minimum i-^i 

Average 5-i8 

Exhausted ginger from English gin-l 

ger-ale works. ' 4.88 

Exhausted ginger from extract works. ; i -52 



62.42 


60.31 


5-50 


9-75 


53-43 


49-05 


2-37 


4.81 


57-45 


54-53 


3-91 


7-74 


59.86 


54.57 


5-17 


6.94 











5.42 
2.82 

4.10 

3-86 
0.54 







; >.. « 














-cl 


ters b 
\ Con- 
ion, a 

ch. 


c3 


<a St 


lii 




1 






■c «■" r' rt 


£.2o 


•S.S 


e<^ 


"Ox 


^u 




^a 


^S< >{g 


5qs 

■j: 


8^ 


g^ 


o'A 


^'^ 



i/ 


DO 


1 


00 


10 


92, 





77 


13 


42 


I 


•23 


6 


15 


I 


.11 


16 


42 







]McGill * records the analyses of ninety-eight samples of ground ginger 
as sold in the Canadian market. Of thirty-two of these, pronounced 
pure on analyses, the follo\\'ing is a summar}': 



Maximum . 
Minimum . 



Moisture , 

or Loss 

on Yiry- I 

ingat 

100°. 



Petro- 
leum- 
ether 
Extract. 



Cold- 
water 
Extract. 



12.00 
9-50 



6.15 
2.78 



15.48 
14.04 



Ash. 



Total. 



7-84 
3-67 



Soluble. Insoluble. 



2.28 



3-99 
1.96 



Alkalin- 
ity of 
Soluble 
Ash as 
KoO. 



■133 
.103 



According to Vogl, the proportion of ginger ash varies quite widely 
according to the kind, but should never exceed S^r- 

Exhausted Ginger and Methods of Detection. — There are two kinds 
of exhausted ginger commercially available for admixture with ground 
spice, as an adulterant. One is the product left after extraction \\-ith strong 
alcohol in the making of extract of Jamaica ginger, and the other the 
residue from extraction with either verv dilute alcohol, or with w^ater, 



* Dept. Inl. Rev. Canada Bui. 48, pp. 10, 11. 



448 



FOOD INSPECTION yIND ANALYSIS. 



in the manufacture of ginger ale. Ground, exhausted ginger is rarely 
substituted wholly for the pure variety^ since, from its lack of pungency, 
the sophistication would h)C too apparent. It is rather used to mix with 
the latter in varying proportions, and as an adulterant of other spices. 
Ginger that has been exhausted by extraction with alcohol has been 
deprived of most of its volatile oil, which is found in the "extract," while 
for the manufacture of ginger ale, a water extract, or at most a very dilute 
alcoholic extract is best adapted. Such a water extract does, as a matter 
of fact, remove much of the valued pungency, so that the residue, or 
exhausted ginger, is rather inert. 

Either the alcohol- or the water-extracted variety of exhausted ginger, 
when present in considerable amount, would be apparent, one by the 
alcohol and ether extract, and the other by the abnormally low cold- 
water extract, and water-soluble ash. 

Dyer and Gilbard * first called attention to the water-soluble ash as 
a reliable means of indicating exhausted ginger. Six samples of ginger 
of known purity were analyzed by them, their results being summarized 
as follows: 



Total Ash. 


Water- 
soluble 
Ash. 


4-1 


3- 


3-1 

3-8 


1.9 

2-7 


2-3 


0-5 


I.I 


0.2 


1.8 


0-35 



Alcohol 

Extract, 

after Ether 

Extract. 



Pure ginger (6 samples) : 



Exhausted ginger (6 samples) 



Highest 
Lowest. 
Average 
Highest 
Lowest. 
Average 



3-8 

2. I 
2.8 

1-5 



Allen and Moor | pointed out the value of the cold-water extract 
as a help in detecting exhausted ginger, especially when taken in con- 
nection with the soluble ash, showing that the presence of this adulterant 
is assured, when the soluble ash is as low as i%, and the cold-water extract 
is lcs> than ?f/( . 

Determination of Cold-water Extract. — Winton, Ogden, and Mitchell's 
Method.! — Four grams of the ground sample are placed in a 200-cc. 
graduated flask, and the latter is filled to the mark with water, and shaken 
at half-hour intervals during eight hours, after which it is allowed to 

* Analyst, XVIII (1893), p. 197. 

t .Analyst, XIX (1894), p. 194. 

t U. S. Dept. of .\gric., Bur. of Chem., Bui. 65, p. 59; Bui. 107 (rev.), p. 164. 



SPICES. 



449 



Stand at rest for sLxteen hours in addition. The contents are then filtered, 
and 50 cc. of the filtrate evaporated to dr^Tiess in a platinum dish. It 
ia then dried at 100° to constant weight and weighed. 

Microscopical Structure of Ground Ginger. — Fig. 87, from Moeller, 
5ho-.vs elements of ginger root, from -.vhich the epidermis has not been 



•J 




Tig. 87. — ^Powdered Ginger under the Microscope. X125. (After Moeller.) 



removed. A bit of the large-celled cork (or dead protective tissue of 
the epidermis) is shown in plan \'iew at (i); at (2) is shown in cross- 
seaion the parenchyma in which the starch is contained, h being an oil- 
cell; (3) shows the parench\Tna in longitudinal seaion, with bast fibers- 
Fragments of spiral ducts are shown at (4), and starch grains at (5). (6) 
is a cross-section in the extreme interior of the root. 

The most prominent featiure of powdered ginger is the starch grains 
(5), which Moeller compares in shap)e to tied sacks. 

Fig. 228, PL XX\TI, is a photomicrograph of pure, ground ginger, 
mounted in water, showing the starch grains inclosed in the cells of the 
parenchyma. Fig. 231 shows the starch grains alone. The granules of 
ginger starch are ellipsoidal, and as a mle verj- clear and transparent, 
being for the most part entirely devoid of either hilum or concentric rings. 



450 FOOD INSPECTION AND ANALYSIS. 

Occasionally granules are to be found, however, with faint concentric 
markings, and even with an apparent hilum. The characteristic form of 
the ginger starch granule is more or less egg-shaped, with a small protu- 
berance near one end. This protuberance serves to readily distinguish 
the starch granules of ginger from those of wheat, with which ginger 
is frequently adulterated. While wheat granules are of various sizes, 
the grains of ginger starch are as a rule much more uniform. 

Adulteration of Ginger. — U. S. standard ginger should meet the follow- 
ing rec^uirements: Starch by the diastase method should not be less than 
42%; crude fiber should not exceed 8%; total ash should not exceed 8%* 
lime should not exceed 1%; ash insoluble in hydrochloric acid should 
not exceed 3%. 

Besides exhausted ginger, the most common adulterants found in 
powdered ginger are turmeric, wheat, corn, rice, and sawdust. Sawdust 
of soft wood is a not uncommon adulterant, and care should be taken 
to distinguish between the wood fiber natural to the ginger root, and that 
of the foreign variety. A careful study should be made of finely ground, 
soft-wood sawdust, with its long spindle cells and lateral pores, as shown 
in Fig. 266, PI. XXXVII, and the wood fiber of the genuine ginger root. 
A large admixture of sawdust would materially increase the percentage 
of crude fiber. 

Fig. 234, PI. XXIX, shows a sample of ginger adulterated with corn 
and wheat. Fig. 232 shows a mass of wheat bran in an adulterated 
sample. 

Fig. 233 shows ginger adulterated with turmeric* 

TURMERIC. 

Nature and Composition.— Turmeric, while largely used as an adul- 
terant of other spices (especially of ginger and mustard), possesses some 
value as a condiment in itself, forming, for instance, the chief ingredient 
of curry powder.f Turmeric {Curcuma longa) belongs to the same 
family {ZingiberacecB) as ginger, having a perennial rootstock, and an 
annual stem. It is a native of the East Indies and Cochin-China. Its 
chief ingredients are starch, a volatile oil, a yellow coloring matter (cur- 
cumin), cellulose, and gum. 

* This photomicrograph is very disappointing, in that it fails to show the intense yellow 
of the central mass of turmeric. 

t Curry powder consists of a mixture of turmeric, cayenne, and various pungent spices. 



SPICES. 



451 



Curcumin (Cj^H^^OJ is insoluble in cold water, but readily soluble 
in alcohol. It is extracted from powdered turmeric by boiling the latter 
with water, filterings and extracting the residue with boiling alcohol. 
The alcoholic solution is filtered, evaporated, and the residue extracted 
with ether. The ether extract contains the curcumin, together with a 
small amount of volatile oil. 

Curcuma oil is an orange-yellow, slightly fluorescent liquid, its specific 
gravity being 0.942. 

The following analyses of turmeric were made in the writer's labo- 
ratorv: 



Variety. 



Mois- 
ture. 



Total 
Ash. 



China i 9 - 03 



Pubna. 
AUcppi. , 

Average . 



9.08 
8.07 

8.73 



5-99 
7.07 



Ash Ash 

Soluble , Insoluble 
inWater. in HCl. 



5.20 
6. 14 
4-74 

5-36 



Total 

Nitrogen, 



1-73 
0.97 

1-56 

1.42 



Protein, 

NX6.25. 



10.81 
6.06 
9-75 

8.88 



Total 

Ether 

Extract. 



10.86 
12.01 
10.66 

II .17 



Variety. 



Volatile 

Ether 

Extract. 



Non-vol- 
atile 
Ether 
Extract. 



Alcohol 
Extract. 



Crude 
Fiber. 



Reducing 
Matter by 
Acid Con- 
version, as 
Starch. 



Starch by 
Diastase 

Method. 



China ^.01 

Pubna 4-42 

Alleppi ' 3- 16 

Average 3-i9 



7.60 
7-Si 



9.22 

7.28 
4.37 

6.96 



4-45 
5-84 
5-83 

5-37 



48.69 
50.08 
50-44 

49-73 



40.05 
29.56 
33-03 

34.21 



Microscopical Structure of Turmeric. — Moeller's representation of 
characteristics of powdered turmeric is reproduced in Fig. 88. The 
epidermis is shown at (i) with one of the numerous, one-celled hairs that 
grow from it, also the scar left after one of the hairs has been removed ; 
(2) shows in plan view the cork immediately under the epidermis. The 
tender-celled parenchyma is shown in cross-section at (3), and in longi- 
tudinal section at (4). In some of the cells of the parenchyma are found 
dark-yellow lumps of resin (h), and vascular ducts (g), but by far the most 
numerous and striking contents of the parenchyma-cells are the bright- 
yellow masses of "paste balls" (3a) and the starch granules, one of 
which is shown in (3). See also Plate XIII. The starch grains in the 
water-mounted powder show under the microscope in masses, usually of 
a deep-yellow color, unless very finely rubbed out, when they appear for 
the most part in fragments. 



452 



FOOD INSPECTION AND AN/ILYSIS. 



The whole starch granule appears somewhat in the fonn of a clam- 
shell, with very distinct markings. When fragments of the starch granules 
are carefully examined, these distinct markings are so strongly charac- 
teristic, even in the smallest pieces commonly found in the powdered 
sample, as to nearly always serve to identify them. See Fig. 171, 
PL XIII. 

Turmeric as an Adulterant. — Turmeric is a material especially adapted 
by its deep-yellow color to intensify mustard and ginger, especially when 




Fig. 88. — ^Powdered Turmeric under the Microscope. X125. (After Moeller.) 



these spices are aduUerated with the Ughter-colored cereal starches, hence 
it is very commonly found in these spices, both with and without other 
adulterants. 

It is also frequently used in small quantities in adulterated cayenne^ 
mace, and various spices, to counteract the colors of other dyestuffs, 
such as ground redwood, which in itself would sometimes be too intense 
if used alone. 



SPICES. 



453 



Turmeric, when present to any marked extent in a powdered spice, 
may be detected chemically, by extracting the material with alcohol, 
pouring off the latter, and soaking in it a piece of filter-paper. Tur^ 
meric, if present, will stain the latter yellow, turning red with alkali, espe- 
cially apparent after dr}-ing. Soak the yellow paper in a solution of borax, 
acidulated sUghtly with hydrochloric acid. When dry, a rose-red color 
will indicate turmeric, turning dark oHve when dilute alkali is appUed. 

MUSTARD. 

Nature and Composition. — Mustard is the seed of the mustard plant, 
an annual belonging to the family CrucifercB, and to the genus Sinapis, 
or Brassica, as it is sometimes called. The plant is an herb, native 
throughout Europe, and cultivated extensively in the United States. It 
grows to a height of from 3 to 6 feet, having yellow flowers and lyrate 
leaves. 

Two varieties commonly used are Brassica or {Sinapis) alba, white 
mustard, and Brassica (or Sinapis) nigra, black mustard, the ground 
spice being as a rule a mixture of the two. In the trade these varieties 
are kno\Mi as brown and yellow mustard respectively. The seeds of 
both varieties are globular, those of the black mustard being small, and 
of a dark-bro^^Tl color on the outside and yellow within. WTiite mustard 
seeds are considerably larger than the black, being pale yellow in color 
on the outside. 

The surface of the black mustard seeds is reticular, and full of 
small depressions, while the white variety is much smoother. There are 
several layers forming the husk of the seed of both varieties, and within 
the husk is the yellowish-colored kernel or embryo, with two cotyledons. 

Both black and white mustard contain from 31 to 37% of fixed 
oil, a soluble ferment known as myrosin, and a sulphocyanate of 
sinapin. Mustard seeds contain no starch, and very little volatile oil 
as such. Black mustard seed contains sinigrin, or myronate of potash 
(not found in the white seed), which, when moistened with water, forms 
by hydrolysis the volatile oil of black mustard, otherwise known as allyl 
isothiocyanate, in accordance with the following equation: 

KCioH,6NS20g+ H,0 = CeH^^Oe + C3H5CNS -h KHSO,. 

Potassium Glucose Mustard Potassiiim 

myronate oil bisulphate 

Mustard Oil (volatile) is a colorless, or shghtly yellow, highly refrac- 
tive liquid of a ver)' strong odor, and capable of bhstering the skin when 



454 FOOD INSPECTION AND ANALYSIS. 

brought in contact with it. It is optically inactive. Its specific gravity 
varies between 1.016 and 1.030. It boils between 148° and 156°. It 
turns reddish brown by exposure to light. 

Volatile oil of black mustard forms thiosinamine with ammonia, as 
follows : 

C3H5CNS +NH3= CS.NH2.NH.C3H5. 

Thiosinamine is soluble in hot water, from which it crystallizes in 
tufts of monochnic crystals, having a melting-point of 74° C. It is pre- 
cipitated by silver nitrate, mercuric chloride, and Mayer's solution. 

White mustard differs from the black in containing a sulphur com- 
pound, sinalhin, C30H42N2S2O15. This is a glucoside. Sinalbin by hy- 
drolysis forms an oil of white mustard, in a somewhat similar manner 
to the potassium myronate of black mustard, and according to the follow- 
ing equation: 

CaoH.^N^S^Oi.-f H2O = C,H,ONCS + CeHi20e + Ci6H3,NO,HSO,. 

Sinalbin Sinalbin Glucose Sinapin acid 

mustard oil sulphate 

Sinalbin Mustard Oil cannot be obtained by the distillation of white 
mustard, being sparingly volatile with steam. 

Sinalbin mustard oil somewhat resembles that from black mustard, 
being quite as pungent, but less strong in odor when cold. It is soluble 
in dilute alkali. 

Fixed oil of mustard is a bland, tasteless, and nearly odorless oil, its 
specific gravity at 15° varying between the hmits of 0.914 to 0.918. It 
is said to be used to some extent as an adulterant of table oils, being 
separated by pressure from the crushed mustard seeds before the latter 
are ground into "flour." The chief use of mustard oil is in mixture 
with other oils as an illuminant. 

MUSTARD FLOUR. — In the process of preparing the ground spice com- 
monly known as mustard "flour," the seeds are first crushed and sepa- 
rated by winnowing from the hulls, the latter being incapable of the fine 
grinding necessary to produce a smooth flour. The yellow hulls are, 
however, found in the cheaper grades ot ground mustard, and both 
varieties of hull are frequently used in the wet mustard preparations, 
sold in bottled form. In order to produce an even, dry powder, free from 
lumps, it is necessary to remove a large portion of the fixed oil, which 
is indeed of no value in the final product, and this is done by subjecting 
the crushed material to hydraulic pressure, during which process the 



SPICES. 



455 



mustard is molded together into thin, hard plates, called "mustard 
cake." This is then broken up and reduced to fine powder by pounding. 
Richardson's * analyses of whole-seed flour, prepared by himself 
without the removal of the fixed oil, are as follows: 






"3 . 








;-o 


0) 


Cc< 


M 


33-56 


.CK) 


34 -«3 


-00 


28.12 


.00 


31.96 


.00 


36.63 


.00 


31-51 


.00 


39-55 


.00 




White seed 

White flour 

Seed husk 

California yellow 
California brown 
English yellow . . 
Trieste brown. .. 



57 
33 
17 
.83 
,11 
.11 
,62 



4-29 
5-23 
4-99 
5-96 
4.88 
4.07 
5-61 



-97 
1.84 



5-40 
9-05 
9-50 
8.50 

16.18 
6.90 

10.84 



28.88 21.33J 4.62 
25-561 20.16! 4.09 
23-44: 27.23, 3.75 
31.13; 16.35I 4.98 
24.69I 12.16 3.95 
30.25' 22.10 4.84 
25.88! 18.87 4.14 



Winton and Mitchell made no full analyses of mustard seed of known 
purity, but the following is a summary of analyses of 18 samples of com- 
mercial mustards, sold in packages in Connecticut, and not found to be 
adulterated : 



Total 
Ash. 



Ether Extract. 



Volatile. 



Non-vol- 
atile. 



Reducing 
Matters 
by Acid 
Con ver- 
sion, as 
Starch. 



Starch 

by 
Diastase 
Method. 



Crude Nitrogen 
Fiber. I X6.2S. 



Maximum 
Minimum 
Average . . 




2.08 



1.07 



.87 
■58 



43-56 
35-63 
39-57 



The following analyses of 5 samples of mustard flour, 6 samples of 
mustard hulls, and 6 samples of whole mustard, were made in the author's 
laboratory' in 1903: 



* U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 2. 



456 



FOOD INSPECTION AND ANALYSIS. 



-■BXQ Aq saa^ 



• 00 O ^ >~ 



r^ f^^C a O- r^ O-OO »n 



t^ Tj- rj- ro ^ 



•uoisa3AU03 



4 oO »ooo 'O I 



nso t^ 0> r^CO . 



". O M 



'O 'toe ■'t - TfoC- a fN 
O 0> ^ ^ O r^oO ^ 00 



•jaqij spnJO 



■qsy PIOX 



•U83 



-xg {ou,03iv 



•asBisBiQ Xq 



•uois 
-jaAU03 PPV •'''^ 



ro -^ -^ O* O O" f 






": rt f^vC -O TfoC o »o 

00 « i^. "^ 'T r^^ ►- r<^ O 

1^ r^ t^ r^ O t^oo 00 00 

f^^N — Tt-MOOCG ^ 

NkOOvO^vowr^ 00 



00 Oi o> o» o^ o> o> 



(-0O NOOvO -to ■* 
00 O O i'JvO fO Tt r^ 



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00 ^O O r^ O ► 



* vO o> o o o o 



-00 n -t > 

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CC 00 o -t • 



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ro ^ f^ to 



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o o o. 
vo r 

to -^ fO rO f^ fO ( 



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y= c o 

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't't-tM OCC33 O. 



) -t '^ r- ^ O vO O 



•13-Bj^xg 






o o o o o o o 
o o o o o o o 



f^sc r-o o 



oooooooo 
oooooooo 



r- ir^vO l^ O r^GC 00 



o o o o o o o 
o o o o o o o 



-xa jama i^iox 



OOUOh. OOt--M 0« 



■j\o i^ o 1^00 00 



•DH 
ui aiqnpsui qsy 



•qsy aiqnios-jaiBj^ 



r- f^ O' o^oo 



Tf -^ ^O t^ I 



•tisy F;ox 



O rt r- u-,sO t/:0 ^ 
lAt'tt't't't-t 



O OO 0> ^,00 fO O f^ 
"■tfO tO-*f*-*'<t 



•annsToj^ 



1 o *^ r- ooo vo 



1 •* ■* o 
) t^ o. t^ r- lovo 



1 ooo r- 



nvO O O i/^O O O 



p.* 









Etc 






^ fe • ■';§ ^ o " 
"i (- 5 c o & & ^s^ <* 






li 



"S'o c ■ 









^•gmo OQwo <; 



SPICES. 457 

Piesse and Stansell give the following composition of mustard ash: 





White Seeds. 


Brown Seeds. 


Yorkshire. 


Cambridge. 


Cambridge. 


Potash 


21.29 
0.18 

13.46 
8.17 
1. 18 
7.06 

O.II 

32-74 
1. 00 
1.82 

12.82 


18.88 
0.21 

9-34 
10.49 

1-03 
7.16 
0.12 

35.00 
1. 12 
1-95 

15-14 


21.41 

0-35 

13-57 

10.04 

1.06 

5-56 

0-15 

37.20 

1. 41 

1.38 

7-57 


Soda 


Lime 


Magnesia 


Iron oxide 


Sulphuric acid 


Chlorine 


Phosphoric acid 


^ilica 


Sand 


Charcoal 




99-85 


100.48 


99.70 



Determination of Myronate of Potassium and Sinapin Sulphocyanate.* 
— Extract at least 50 grams of the powdered material with several por- 
tions of a mixture of equal parts of water and alcohol, digesting with the 
aid of heat in a flask with a return-flow condenser. Evaporate the 
alcoholic extract in a tared dish to dryness, and heat at 105° to constant 
weight. After weighing, incinerate the residue at a temperature suf- 
ficiently high to transform to the neutral sulphate the potassium bisulphate 
resulting from the decomposition of the myronate. The weight of 
myronate of potassium is obtained by multiplying the weight of neutral 
sulphate (the final ash) by the factor 4.77. This, deducted from the 
total weight of the dried alcoholic residue as above, gives that of the 
sulphocyanate of sinapin. 

Determination of Mustard Oil in Mustard Flour. — Roeser^s Method.^ 
— Mix 5 grams of the sample with 60 cc. of water and 15 cc. of 60% alcohol, 
and let stand for two hours. Distil into a flask containing 10 cc. of 
ammonia, and, after about two-thirds of the solution have been distilled 
off, mix the ammoniacal distillate with 10 cc. of tenth-normal silver 
nitrate solution, and allow the mixture to stand for twenty-four hours, 
after which make up with water to 100 cc. Filter, and treat 50 cc. of 
the filtrate with 5 cc. of tenth-normal potassium cyanide solution. Titrate 
the excess of cyanide with the tenth-normal silver nitrate, using as an 
indicator a 5% solution of potassium iodide, made slightly ammoniacal. 

* Girard et Dupree Analyse des Matieres Alimentaires, p. 678. 
f Abs. Analyst, XXVII, 1902, p. 197. 



458 



FOOD INSPECTION /tND /IN A LYSIS. 



The j)crccnlagc of mustard oil present is found by multiply- 
ing by 2 the number of cubic centimeters of silver nitrate solution 
taken up by the oil, and multiplying this product by the factor 

0.3137- 

Microscopical Characteristics of Powdered Mustard. — The j^rincipal 

features of jKjwdered l)la(k mustard arc rcj)resented in Fig. 89* The 

seed shell or hull is sh(jwn in cross-section 
at (i), a being the j^olygonal-cellcfl epi- 
dermis, h a layer of i;alisade-sha))ed cells, 
and c a thin pigment layer, the brown 
coloring matter of which is colored blue l)y 
iron salts; d is the aleurone layer and ob- 
scure j)arenchyma, and e the small-celled 
tissue of the cotyledons, containing fixed oil 
and albumen. 

(2) shows in plan view the various 
layers of the seed shell, the letters of 
reference corresjjonding to those of (i). 

(3) shows in ])lan view a bit of the 
extreme outer mucilaginous layer of the seed- 
hull. 

Fig. 247, PI XXXII, shows the ap- 
])earance in water- mount of pure ground 
mustard. This is a ])hotomi(rograph of the ground hulled seed with- 
out the extraction of the oil, and should not Ik- taken as a standard 
for comniercial mustard "Hour," from which, as a rule, a large por- 
tion of the oil has been removed. The cellular tissue of the mustard 
shows in the form of granular masses of loose, fine gray texture; the 
globular bodies are oil drops. Here and there through the field of 
ordinar)' ground mustard are to be seen j)atches of the yellowish layer 
of the seed skin of the brown mustard, a mass of which is shown in 
Fig. 248, with dark-brown spots distributed regularly through it. This 
is the layer shown at (2) h, Fig. 89. The hull of the yellow seed, also 
commcm in [)owdered mustard, is similar in ai)j)earance, having dark- 
brown spots, but with nearly colorless or gray cell walls, instead of yellow. 
Patches of the outer hull layer rei)resented by (3) in Fig. 89 are also 
very common in the commercial mustard flour. Mustard contains no 
starch. 




Fig. S9. — Powdered Mustard 
under the Microscope. X12S. 
(After Moeller.) 



SPICES. 459 

Adulteration of Mustard. — U. S. standards for mustard are as follows: 
Sl'irch, by diastase method, should not exceed 2.5% and total ash should 
not exceed 8%. 

It is difficult to draw the line between the amount of mustard hulls 
w'hich may naturally occur in ground mustard, and the excess amount 
which is sometimes added as an adulterant. Samj;les in which the 
patches of hulls [predominate in number over the regular cellular tissue 
of the seed, as seen under the microscope, are undoubtedly adulterated 
by the fraudulent admixture of ground hulls, that have been separated 
out from the crushed mustard seeds intended for higher grades. Samples 
of mustard flour thus adulterated are common.* 

In determining starch in mustard, it should be borne in mind that 
mustard hulls have considerable reducing matter by the diastase process. 

The most common adulterants of mustard, other than excess of hulls, 
are wheat, turmeric, millet and other weed seed, and rice. Yellow, oil- 
soluble azo-dyes are also employed. 

Other adulterants fouiid in Massachusetts have been jxjtato starch, 
cayenne, corn, and gyj)sum or "terra alba" (the latter being found in 
one instance to the extent of 21%). 

Fig. 250, PI. XXXIII, shows a sample of mustard adulterated with 
wheat bran. Very little besides the adulterant appears in this field. 

The common practice of adulterating mustard with wheat is an out- 
growth of the old notion that a certain amount of wheat flour was neces- 
sar}' U) prevent lumping. 

Samples of cheaper mustard flour are occasionally founrl to contain 
small amounts of wheat and foreign starch, aj^parently of accidental occur- 
rence. This is undoubtedly due to the fact that in some localities wild 
mustard often grows in the wheat-fields, so that after the wheat crop has 
been harvested, the mustard is gathered and sold. Such mustard seed 
would naturally contain varying admixtures of wheat, and sometimes seeds 
of various weeds, which it would not be profitable to separate out, even 

* It is (laimcd by some manufacturers that the hulls thus removed arc not used as an 
adulterant of cheaper mustard flours, in view of the fact that it is difficult or impossible to 
grind them finely enough, but that they are used up in the manufacture of compound mus- 
tard yjastes. A sample of ground mustard was recently found by the writer, in which it 
was noticed that a large number of yellow lumps were distributed through it. These lumps 
were picked out, transferred to the microscope slide, and crushed and ruVjbed out under 
the cover-glass. Examined under the microscope, they were found to consist entirely of 
a mixture of mustard hulls and turmeric, which would seem to show that hulls were present 
in this case as an adulterant. 



460 FOOD INSPECTION AND ANALYSIS. 

if it were possible to do so. Such contaminated mustard enters into the 
manufacture of the cheapest grades of flour only. 

Fig. 249, PI. XXXIII, shows the flour of the Dakota brown mustard, 
or charlock {Brassica Sinapistrum), which is the commonest of the wild 
mustards. This species is characterized by the presence in the pallisade 
cells of a dark brown substance, which on treatment under the cover glass 
with chloral hydrate solution assumes a beautiful blood-red color. This 
highly characteristic reaction is hastened by gentle heating, and permits 
the ready detection of charlock in mustard flour. 

Detection of Coloring Matter.* — Turmeric is best detected by the 
microscope (see pp. 451 and 452). OJ4-soluble coal-tar dyes should be 
tested for as in the case of cayenne. Nitro colors, such as naphthol yellow 
(Martins yellow) and naphthol yellow S, are detected by dyeing tests, with 
subsequent examination of dyed fabric according to the scheme on p. 799. 

Prepared Mustard. — This product consists of a mixture of ground 
mustard seed or mustard flour with salt, spices, and vinegar. The U, S. 
standards require that it should contain not more than 24% of carbo- 
hydrates calculated as starch, not more than 12% of crude fiber, and not 
less than 35% of protein. 

Most of the product consumed in the United States is of domestic 
manufacture, although until the passage of the federal food law it was 
customary to designate it German or French mustard, or label it in a foreign 
language. 

Composition and Adulteration. — The common admixtures are wheat 
flour, maize flour, and other starchy matter, mustard hulls, sugar, chemical 
preservatives, and artificial colors. 

Of 28 brands examined in Connecticut in 1905 by Winton and Andrew,! 
13 contained cereal flour (wheat or corn), 4 salicylic acid, and 25 
artificial color (turmeric, nitro-color or azo-color). A summary of the 

* Recently some very yellow samples of powdered mustard have appeared on the 
market that are apparently free from foreign color. Their method of manufacture is kept 
secret. From the fact that they contain nearly, if not quite, the full content of fLxed mus- 
tard oil that would be present if the oil had not been previously expressed, and for various 
other reasons, it is probable that the color is due largely to the presence of the fixed oil, which 
has a deep-yellow color, and which has hitherto been generally removed for purposes of fine 
pounding and to avoid caking. 

In such samples, the oil, previously pressed out, is, after pounding, restored, and with 
it much of the color. Incidentally in such a process oil-soluble coal-tar dyes may conve- 
niently be dissolved in the mustard oil, in order to intensify the color, and the analvst should 
be on the outlook for such foreign colors. 

t An. Rep. Conn. Exp. Sta., 1905, p. 123. 



SPICES. 



461 



analyses of those brands free from cereal flour and those containing it 
follows : 



In the Material as Sold. 



Water. 



Acid- 
ity 
Calcu- 
lated 

as 
Acetic 
Acid. 



Total 
Solids. 



Total^'o""- 



Ash ; 

other: Pro- 
than| tein. 
Salt 



Reduc- 
ing 
Crude Matters 
Fiber, by Acid 
Conver- 
sion, as 
Starch. 



Nitro- 
gen- 
free 
Ex- 
tract. 



Fat. 



Prepared mustard free 
from cereal flour: 

Maximum 

Minimum 

Average , 

Prepared mustard con- 
taining cereal flour: 

Maximum 

Minimum 



83.68 
73 01 
78.59 



85 63 
70.44 



3-66 



23.67 
13-32 
18.36 



27.70 
9-89 



4.79 369 
2.601 1.78 
3-381 2.32 



4-21, 3.39 
2 . 28, 1 . SI 



I-3I 
0.82 
1 .06 



I. 16 
0.48 



6. 12 
3-62 
4.71 



6.38 
I -53 



2 . 92 
1.83 



13-69 



6. II 
4.21 
4-98 



IS-3S 
3-82 



7-23 
2 . 12 
4.12 



3-2S 
o. 76 



Prepared mustard free from cereal fiour: 

Maximum .^-. 

Minimvun 

Average 

Prepared mustard containing cereal flour: 

Maximum 

Minimum 

Whole mustard seed (analysis by the author 
See page 456) : 

Maximum 

Minimum 

Average 



In the Dry, Fat, and Salt-free Material. 



Ash. 



10.66 
7-35 
8.94 



9.68 
4.84 



7-64 
6.28 
6.83 



Protein. 



43-94 
32.01 
39-44 



33-89 

21 .37 



48.31 
37-50 
44-31 



Crude 
Fiber. 



9-89 



18.44 
0.45 



8.05 



Reducing ' 
Matters jNitrogen- 
by Acid free 

Conver- Extract, 
sion, as 
Starch. 



24.37 
16.82 
20. II 



59.22 
24-51 



15-91 
11-94 
13-82 



44-76 
34-98 
41.73 



66.42 
41.79 



48.55 
37-84 
40.81 



The following methods for the analysis of prepared mustard were 
used b}' \\'inton and Andrew, and afterwards adopted by the Association 
of Ofticial Agricultural Chemists: 

Solids, Ash and Salt are determined in one portion of 5 grams of 
the thoroughly mixed material, following the usual methods. The salt 
is calculated from the percentage of chlorine. 

Ether Extract. — Ten grams of the material and about 30 grams of 
sand are placed in a capsule, and dried on a water bath with stirring. 
The dried residue is ground and extracted with anhydrous ether in the 
usual manner. 



4f-2 FOOD INSPECTIOhT AND ANALYSIS. 

Reducing Matters by Acid Conversion are determined directly in 
the material, without previously washing, by the method described on 
page 411. 

Crude Fiber. — Eight grams of the material (equivalent to about 2 grams 
of dry matter) are treated in the usual manner (page 277), except that 
care is taken to add at first only a small amount of the 1.25% acid or alkali, 
and shake thoroughly until all lumps are broken up, as otherwise these 
lumps will resist the action of the solution and the results will be high. 

Protein. — Nitrogen is determined by the Kjeldahl or Gunning method, 
and the result multiplied by 6.25. 

Dyes and Preservatives are detected by the methods described in 
chapters XMI and XVIII. 

NUTMEG AND MACE. 

Nature and Composition.^ — Both nutmeg and mace occur in the fruit 
of several varieties of trees of the genus Myrlstica, especially of the Myri- 
stica fragrans or Myristica moschata, belonging to the family Myristi- 
cacea. The nutmeg tree is a native of the Malay archipelago, and grows 
from 20 to 30 feet high, somewhat resembling the orange tree in appear- 
ance. It does not produce flowers till its eighth or ninth year, after which 
it bears fruit constantly for many years. The fruit is a globular, pendant 
drupe, about 5 cm. in diameter, of a yellowish-green color, the pericarp 
of which, when ripe, sphts in two, showing within it the kernel, completely 
surrounded by a fleshy, fibrous aril, or covering of a crimson color. This 
covering, when dried, furnishes the mace of commerce, while the inner 
kernel, which is a hard, brown seed, is the nutmeg. 

The jiutmeg seed or kernel, when gathered, is surrounded by a thick 
tegument, marked with depressions corresponding to the lobes of the 
aril or mace, and by a second thin, inner envelope, closely adhering to 
the seed. The whole seed is dried in the sun for about two months, or 
by the aid of heat, the tegument becoming separated from the kernel, 
and, by breaking with a hammer, is readily removed. The kernels 
are then commonly washed in milk of lime, and again dried, or they 
are sometimes treated with dry, powdered, air-slaked lime. Liming is 
alleged to prevent sprouting and ward off the attacks of insects. The 
so-called brown nutmegs of commerce are those which have not been 
treated or coated with lime. 



SPICES. 



463 



NUTMEGS arc spheroidal, somclimes nearly spherical, from 20 10 25 
mm. long and 15 to 18 mm. in diameter. The outer surface is som_ewhat 
furrowed. A cross-section of the kernel shows the grayish-brown, starchy 
endosperm, mottled with the dark-brown, resinous \'eins of the peris})erm. 
These veins on pressure with the linger nail present an oily appearance. 
Near the end of the nutmeg which is attached to the stem, is a small 
cavity, in which is the undeveloped embryo with two cotyledons. 

Nutmeg contains a considerable amount of fixed oil, a volatile oil, 
starch, and albuminous matter. Its volatile oil is colorless, and is soluble 
in three parts of strong alcohol. The specific gravity of nutmeg oil 
varies between 0.865 and 0.920, and its specific rotary power (0)^ = 14 
to 28. 

Richardson's analyses of. three samples of nutmeg are as follows: 



Water. 



Ash. 



Volatile 
i Oil. 



Fixed 
Oil or 
Fat. 



Starch, 
etc. 



Crude 
Fiber. 



Albu- 
minoids. 



Nitro- 
gen. 



Whole limed 6.08 

Ground limed 4- 19 

Ground ! 6.40 



3-27 
2.22 

3-15 



2.84 

3-97 
2.90 



34-37 
37-30 
30.98 



36.98 
40.12 
41-77 



11.30 
6.78 
9-55 



5-i6 
5-42 
5-25 



-83 
.87 



Konig gives the following minimum and maximum composition of 
nutmeg: 



Miniinum. 



Maximum. 



Water 

Albuminoids. . 

Volatile oil 

Fat 

Carbohydrates, 

Cellulose 

Ash 



4.2 
5-2 

2-5 

31.0 

29.9 

6.8 
2.2 



12.2 
6.1 
4.0 

37-3 

41.8 

12.0 

3-3 



Winton, Ogden, and Mitchell analyzed four samples of nutmeg of 
known purity, the following being maximum and minimum results: 



Maximum . 
Minimum . 



Moisture. 



10.83 
5-79 



Total. 



3.26 



Ash. 



Soluble in 
Water. 

1.46 
0.82 



Insoluble 
ic HCl. 



o.oi 
0.00 



Ether Extract. 



Volatile. 

6.94 
2.56 



Non-vola- 
tile. 

36.94 
28.73 



464 



FOOD INSPECTION ^ND ANALYSIS. 



Alcohol 
Extract. 



Reducing 
Matters by 
Acid Con- 
version , as 
Starch. 



Starch by 
Diastase. 



Crude 
Fiber. 



Nitrogen 
X6.2S. 



Total 
Nitrogen. 



Maximum. 
Minimum. 



17-38 
10.42 



25.60 
17.19 



24.20 
14.62 



3-72 
2.38 



7.00 
6.56 



1. 12 
I. OS 




Microscopical Structure of Nutmeg. (Fig. 90.) — The thin- walled 
cells of the parenchyma of the endosperm or albumen are shown at 

(i), with starch grains. Simple and com- 
pound granules of the starch are shown at 
(2). Aleurone grains appear as shown at 
(3), and (4) represents in plan view the 
epidermis, or brown seed coat, with its 
numerous layers of flat cells. Powdered 
nutmeg under the microscope in water- 
mount shows most commonly a sponge- 
Hke, loose meshwork of bruised or broken 
Fig. 90.— Powdered Nutmeg cellular tissue, with many starch granules, 

under the Microscope. X125. , . , j. . r 4.1 -j 

^^ „ s and occasional fragments 01 the epidermis. 

(After Moeller.) ° ^ ^ 

Fig. 240, PI. XXX, is a photomicrograph 
of a water-mounted sample of pure nutmeg. The starch granules of 
nutmeg are different from other starches in appearance, being almost 
circular as a rule, quite uniform in size (averaging 0.006 mm. in 
diameter), and having very distinct central hyla. 

Adulteration of Nutmeg. — The U. S. standards for nutmegs 
are as follows: Non- volatile ether extract should be not less than 
25%; total ash should not exceed 5%; ash insoluble in hydro- 
chloric acid should not exceed 0.5%; crude fiber should not exceed 

10%. 

This spice is more often sold in the whole form, since the house- 
wife much prefers to grate the whole nutmeg, rather than to use 
the ground material. It is hence less liable to adulteration than 
the other spices, though of late more of the ground nutmeg is 
being sold in packages. Samples of ground nutmeg have been 
found in Massachusetts adulterated with wheat and nutshells. Ono 
sample was found to contain at least 25% of ground cocoanu^ 
shells. 

Nutmegs which have become mouldy, or have been eaten out by 
insects, have been imported for grinding, as sound nutmegs are not readily 
reduced to a powder. Such a product is obviously unfit for consumption. 



SPICES. 



465 



An inferior variety is known as the Macassar nutmeg. This lacks 
much of the agreeable pungency of the better grades. 

Mace. — The crimson-colored aril that surrounds the nutmeg kernel 
within the pericarp, as above described (p. 462), has many narrow, flattened 
lobes. In the process of drying to form the mace of commerce, it loses 
its brilhant red color, and turns a yellowish brown. When dried, it is 
brittle, somewhat translucent, and of a pungent odor. Whole mace 
appear on the market in the form of flat membranous masses, 3 to 4 cm. 
long. 

It contains no starch as such, but has a modified form of starch known 
as amylodextrin. This is a carbohydrate, C38Ha203i+H20, which pro- 
duces with iodine a red coloration. Mace has a large amount of fixed 
oil, as well as considerable resinous and albuminous matter, and a vola- 
tile oil which much resembles that of nutmeg. 

The specific gravity of volatile oil of mace is rather higher than that 
of nutmeg oil. Its specific rotary power, (a)^ = ioto2o. 

Konig's figures for the composition of mace are as follows: 





Minimum. 


Maximum. 


Water 


4-9 

4-6 

4.0 

18.6 

41.2 

4-5 
1.6 

45-1 


17-6 
6.1 

8-7 
29.1 

44-1 
8.9 

4-1 

55-7 


Albuminoids 


Volatile oil 


Fat 


Carbohydrates 


Cellulose 


Ash 


Alcoholic extract 





Richardson gives the following as the results of analyses of three 
samples made by him: 



Water. 


Ash. 


Volatile 
Oil. 


Resin. 


Unde- 
ter- 
mined. 


Crude 
Fiber. 


Albu- 
minoids. 


Nitro- 
gen. 


Whole mace 5.67 

Ground mace 4.86 

Ground mace 10.47 


4.10 
2.65 
2.20 


4.04 
8.66 
8.68 


27.50 41.17 
29.08 35.50 


8.93 
4-48 
6.88 


4-55 

6-13 
5.08 


•73 
.98 
81 











Winton, Ogden, and Mitchell's analyses of four samples of pure Banda 
or Penang mace, as well as of Bombay and Macassar mace, are sum- 
marized as follows: 



466 



FOOD INSPECTION AND ANALYSIS. 







Ash. 


Ether Extract. 




Total. 


Soluble in 
Water. 


Insoluble 
in HCl 


Volatile. |Non-vola- 


True mace : Maximum 

Minimum 

Average 

Macassar 


12.04 
9.78 

11.05 
4.18 
0.32 


2.54 
1. 81 
2.01 
2.01 
1.98 


I -06 

I-13 
l.ll 

1-37 


0.21 
0.00 
0.07 
0.03 
0.07 


8.65 
6.27 
7-58 
5-89 
4-65 


23.72 
21.63 
22.48 

53-54 
59.81 


Bombay (adulterant) 




Alcohol 
Extract. 


Reducing 
Matters by 
Acid Con- 
version, as 
Starch. 


Starch by 
Diastase.* 


Crude 
Fiber 


Nitrogen 
X6.25. 


Total 
Nitrogen. 


True mace: Maximum 

Alinimum 

Average 

Macassar 

Bombay (adulterant) 


24.76 
22.07 
23.11 
32.89 
44-27 


34-42 
26.77 

31-73 
10.39 
16.20 


30-43 
23-12 
27.87 
8.78 
14-51 


3-85 
2.94 
3.20 

4-57 
3.21 


7.00 
6.25 

6-47 

7.00 
5.06 


I. 12 
I -OO 

1-03 
I. 12 
0.81 



* The figures in this column do not express starch, but amylo-dextrin, which like starch may be 
determined by the diastase method. 



Microscopical Structure of Mace. — Fig. gi shows characteristics of 
mace, (i) being a cross-section through it, (2) a plan view of the 

epidermis, showing its elongated, often 
l^^p^^^^- ^s-fe ;2 nearly rectangular cells, and (3) the large- 

celled parenchyma, in which are numerous 
oil globules. The contents of the paren- 
chyma cells are for the most part color- 
less, consisting of protein, fat, and 
granules of amylodextrin, which are shown 
at (4). At (5) are shown fragments of 
vascular tissue. 

The water-mounted powder of pure 
mace shows no highly colored fragments, 
Fig. 91.— Powdered Mace under ^ut as a mass, is white or grayish, and 
i>/ „ ^'f^^'^^P^" ^^^5' ( ter ^^ loose tcxture. Occasional pale, yel- 

Moeller.) ^ ' ^ 

lowish, lumpy masses appear, and pale- 
brown fragments of the seed coating. The amylodextrin granules 
(which are colored red-brown by solution of iodine) are very 
small. 

Adulteration of Mace. — U. S. standard mace should contain not less 
than 20 nor more than 30% of non- volatile ether extract; nor more than 




SPICES, 467 

3% of total ash; nor more than 0.5% ash insoluble in hydrochloric acid; 
nor more than 10% of crude fiber. 

Turmeric and cereal starches are not uncommonly found in mace, 
but by far the most common adulterant is the so-called false, or wild 
mace, otherwise known as Bombay mace. 

Bombay Mace {Myristica jatua) is almost entirely devoid of odor 
or taste, being nearly as inert as so much starch. It is most properly 
regarded as an aduherant from its lack of pungency, even though in a 
sense it is a variety of mace. 

Its non-volatile ether extract is twice as high as that of Penang mace, 
and at room temperature the fixed oil of Bombay mace is a thick and 
viscous fat, while that of Penang and other maces is a thin oil. 

The refractive indices of the fixed oils of various species of pure, as 
well as of Bombay mace, as determined by Lythgoe in the writer's labora- 
tory, are as follows : 

no at 35° C. 
Banda Mace (i) 1.4848 

(2) 1-4747 

" _ '' (3) 1-4829 

Batavia ]SIace (i) i -4893 

(2) 1-4975 

Papua Mace (i) i .4816 

(2) 1-4795 

West Indian ^Nlace (i) i .4766 

Bombay Mace (i) 1-4615 

(2) 1-4633 

The microscope indicates at once when Bombay mace is present 
in a sample. The oil glands situated in the outer layers of Bombay mace 
are ver\' strongly colored, and contain a deep-red, resinous substance, 
ver}' different from anything to be found in true mace. The glands of 
the more interior layers of wild mace have, moreover, a balsam-like 
substance of a bright-yellow color. In powdered Bombay mace, when 
mounted in water, nearly ever)' field shows both the red and the yellow 
lumps in considerable number. 

Hefelmann's Test jor Bombay Mace * consists in saturating a strip 
of filter-paper with an alcoholic solution of the mace, and removing the 
excess of liquid by pressure between filter-paper. On treating with a 

* Pharm. Zeit., 1891. 



468 FOOD INSPECTION AND ANALYSIS. 

drop of dilute sodium or potassium hydroxide solution, a red color is 
produced in presence of the wild mace. 

Waage^s Test. — One part of the mace is extracted with ten parts of 
alcohol, and potassium chromate solution is added to the extract. If 
Bombay mace is present, the solution becomes red, and the precipitate, 
which is at first yellow, becomes red on standing. True mace gives a 
yellow solution and precipitate, and the latter does not change greatly on 
standing. 

Turmeric is tested for chemically as on p. 789. 

Macassar Mace is sometimes designated as wild mace, but it is by 
no means as inert as the Bombay variety, and possesses a wintergreen- 
like odor. Its taste, while distinctive, is not that of true Pcnang mace. 
It is distinctly an inferior article, and its volatile oil content, as shown 
by the analyses on p. 466, is considerably below the minimum for true 
mace. 

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(See also References on the Microscope, p. 98.) 

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Chem., 1893, P- 13^- 
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p. 858. 
BOHRISCH, P. Ueber den Nachweis einer Kunstlichen Farbung des Senfs. Zeits. 

Unters. Nahr. Genuss., 8, 1904, p. 285. 
BussE, W. Ueber Gewurze. I. Pfeflfer. II. Muskatniisse. III. Macis. Arbeit, a. d. 

Kais. Gesundheits., 9, 1894, p. 509; 11, 1895, p. 390; 12, 1896, p. 628. 
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Unters. Nahr. Genuss., 7, 1904, p. 590. 
Delaite, J. Untersuchung von Senfmehl. Rev. Int. des Falsif., 1897, pp. 10, 37. 
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Dyer u. Gilbard. Unterscheidung zwischen unverfalschtem und extrahirtem Ingwer. 

Chem. Ztg., 17, 1893, p. 838. 
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SPICES. 469 

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Hanausek, T. F. Zur Charakteristik des Cayenpfeffers. Zeits. fur Nahr. Unters. 

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95- 

Gewiirzfalschungen. Apoth. Ztg., 1894, p. 582. 

Gefalschte und echte Macis. Rev. Inter. Fals., i, 1887, p. 23, 

Hanus, J. Beitrag zur Kenntnis verschiedener Arten von Zimmet. Zeits. Unters. 

Nahr. Genuss., 7, 1904, p. 669. 
u. BiEN, F. Zur Kentniss der Zuckerarten der Gewiirze. Zeits. Unters. Nahr. 

Genuss., 12, 1906, p. 395. 
Hartwich, C. Fine Bemerkungen liber den Pfeffer. Zeits. Unters. Nahr. Genuss., 

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Hebebrand, a. Die Beurteilung des Pfeffers nach dem Gehalte an Rohfaser und 

Piperin. Zeits. Unters. Nahr. Genuss., 6, 1903, p. 345. 
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Unters. Nahr. Genuss., 9, 1904, p. 200. 
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Macfarlane, T. Mustard. Canada Inl. Rev. Dept., Bui. 19. 

Mustard. Canada Inl. Rev. Dept., Bui. 50. 

McGiLL, A. Cloves. Canada Inl. Rev. Dept., Bui. 73. 

Ground Ginger. Canada Inl. Rev. Dept., Bui. 48. 

■ Pepper. Canada Inl. Rev. Dept., Bui. 20. 

Reich, R. Ingwer und e.xtrahierter Ingwer. Zeits. Unters. Nahr. Genuss., 14, 

1907, p. 549- 
Richardson, C. Spices and Condiments. U. S. Dept. of Agric, Div. of Chem., Bui. 

13, part 2, 1887. 

RoETTGER, H. Die Gewiirznelken, ihre Verfalschung und Beurtheilung. Ber. XL 
Vers. d. freien Verein bayr. Vertreter d. angew. Chem. in Regensburg, 1892, 
p. 66. 

SoLSTEiN, P. Banda und Bombay Maces. Pharm. Ztg., 1893, pp. 454, 467. 

Spath, E. Neue Verfalschungen von Gewiirzen. Forsch. iiber Lebensm., 3, 1896^ 
p. 308. 



470 FOOD INSPECTION AND ANALYSIS. 

Spath, E. Zur mikroskop. Priifung des Piments. Forsch. iiber Lebensm., 2, 1895, 

p. 419. 
Zur Priifung und Beurteilung des gemahlenen schwarzen Pfeffers. Zeits. Unters. 

Nahr. Genuss., 9, 1905, p. 576. 
Vorschlage des Ausschusses zur Abanderung des Abschnittes " Gewiirze" der 

"Vereinbarungen. " Zeits. Unters. Nahr. Genuss.. 10, 1905, p. 16; 12, 1906, 

p. 12. 
Der Nachweis von Zucker in Macis und in Zimt. Zeits. Unters. Nahr. Genuss., 

II, 1906, p. 447. 
Sprinkmeyer, H., u. FiJRSTENBERG, A. Beitrage zur Kenntnis der Gewiirze. Zeits. 

Unters. Nahr. Genuss., 12, 1906, p. 652. 
VOGL, A., and Hanausek, T. F. Untersuchung der Gewiirze. Sudd. Apoth. Ztg., 

1896. 
Waage, T. Banda und Bombay Maces. Pharm. Centralbl., 33, 1892, p. 372. 
Warburg, O. Die Muskatnuss, ihre Geschichte, Botanik, Kultur, u. s. w. Leipzig, 

1897. 
Weigle, T. Untersuchungen iiber die Zusammensetzung des Pfeffers. Ber. Pharm. 

Ges., 1893, p. 210. 
WiNDiscH, R. Beitrage zur Kenntnis des Aschengehaltes des Paprika. Zeits. Unters. 

Nahr. Genuss., 13, 1907, p. 389. 
WiNTON, A. L. Spices. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, 1902. 

Microscopy of Vegetable Foods. New York, 1906. 

Conn. Exp. Sta. An. Rep. 1896, et seq. 

Mass. State Board of Health An. Reports, 1883, et seq. 

U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 162 



CR\PTER XIII. 



EDIBLE OILS AND FATS. 



Nature and Properties. — The oils and fats are the glycerin salts or 
glycerides of the fatty acids, the most important, on account of their 
occurrence in nearly all fats and oils, being the triglycerides of oleic, 
palmitic, and stearic acids, known as olein, palmitin, and stearin, 
respectively. 

Fats and oils are insoluble in water, and are almost insoluble in cold 
95% alcohol, tho^'.gh they are somewhat soluble in absolute alcohol. 
They are readily soluble in ether, petroleum ether, chloroform, amyl 
alcohol, oil of turpentine, and carbon bisulphide. 

Following is a list of the fatty acids whose glycerides are found in 
edible oils and fats, together with their melting- and boiling-points when 
these have been determined, and the oils and fats in which thev occur. 



ACIDS OF THE ACETIC SERIES CnH,„0^* 



Name. 


Fomnila. 


Melting- 
point. 


Boiling- 
point. 


Occurrence in Oils and Fats. 


But}Tict 


C.HjO, 


-6.5= 


162.3 


Butter, cocoa butter. 


Caproicf 


QH12O; 




200 


Butter, cocoanut oiL 


CapnUct 


CsH«0, 


I'e.'s 


236 


U <I 


Caprict 


CiqH^Oj 


3^-3 


268-270 


(( <l 


Laurie 


^121124^2 


43-6 


176 


Cocoanut oU, cocoa butter. 


Mj-ristic 


Ci^HjgO, 


53-8 


196.5 


" sesame oiL 


Palmitic 


CrtH^O, 


62.6 


215 


Nearly all oils and fats. 


Stearic 


QsH3,0, 


^.3 


232-3 


Fats and nearly all oils, except 
olive and com. 


Arachidic .... 


CgjH^Oj 


77 


.... 


Peanut, olive f trace), rape (trace). 


Behenic 


C^^Oj 


83-84 


.... 


Rape, mustard. 


Lignoceric. . . . 


C.Ji,,0, 


81 


.... 


Peanut. 



* Lewkowitsch, Oils, Fats, and Waxes, 3d ed. (1904). PP- 63-7: 

t These four acids are the only ones that can be distilled under ordinary pressure without becom- 
ing decomposed. 

471 



472 



FOOD INSPECTION ^ND AN /I LYSIS. 
ACIDS OF THE OLEIC SERIES CnHgn-^O,. 



Name. 


Formula. 


Melting- 
point. 


Boiling- 
point. 


Occurrence in Oils and Fats. 


Hypogseic 

Oleic 

Iso-oleic * 

Rapic 

Erucic 


C16H30O2 
C18H34O2 

Cl8"34^-^2 

C.8H34O2 

v-22"4202 


33° 

14° 

44-45° 

33-34° 


2^6° 
232.5° 

264° 


Peanut. 

Nearly all fats and oils. 

Rape and mustard. 



ACIDS OF THE LINOLEIC SERIES CnH^-.O, 



Name. 


Formula. 


Melting- 
point. 


Boiling- 
point. 


Occurrence in Oils and Fats. 




CisHaz^z 


Under- i8°C. 




Olive, cottonseed, peanut, sesame, 
cocoa butter, poppy seed, sun- 
flower. 









* Solid oleic acid. 



Saponification of Fats and Oils. — By this term is meant the decom- 
position of the glycerides composing the fats or oils, whereby the tri- 
atomic alcohol glycerin and the fatty acids are separated. The sapon- 
ification process is commonly applied in carr}dng out many determina- 
tions of value on fats and oils, such as those of the soluble and insoluble 
fatty acids, the Reichert value, etc. As commonly carried out, the tri- 
glycerides are first split up into glycerin and the soluble soaps of the fatty 
acids by the action of caustic alkali, usually in solution in alcohol. This 
part of the process in the case of a given oil, composed, for example, of 
stearin, olein, and palmitin, is illustrated as follows: 



(i) C3H5(C,sH3503)3+3KOH = 

Stearin or 

triglyceryl 

stearate 

(2) C3H3(C,eH3,03)3+3KOH = 

Palmitin or 
triglyceryl 
palmitate 

(3) C3H,(Q«H3303) + 3KOH = 

Olein or tri- 
glyceryl oleate 



= C3H,(OH)3+3K(C,,H3A) 

Glycerin Potassium 

stearate 

= C3H,(OH)3+3K(C,,H3,0,) 

Potassium 
palmitate 

:C3H5(OH)3+3K(C,«H3303) 

Potassium 
oleate 



These "soaps, " or potassium salts of the fatty acids, are further decom- 
posed by the action of sulphuric acid into the free fatty acids and potas- 
sium sulphate, in the case of potassium stearate, as follows: 



2K(C,,H3A) + H2SO,=K2SO,+ 2H(Ci3H350a) 

Potassium stearate Stearic add 



EDIBLE OILS AND FATS. 475 

ANALYSIS OF EDIBLE OILS AND FATS. 

No class of food products presents more difl&culties to the analyst 
than the fats and oils, in that the various physical and chemical constants 
by which one derives information as to their nature or purity differ within 
such wide limits that it is not easy to prescribe absolute standards. Many 
elements enter in to cause this variation, chief among which are, in 
vegetable oils, the large number of varieties of fruits or seeds from which 
each oil is in different localities obtained, as well as the vaiious grades 
of each oil with respect to refining. In the animal fats, butter and lard, 
the kind of food fed to the animal undoubtedly influences the constants 
of the fat, and in all fats and oils much depends upon their age, and the 
conditions under which they are kept as to temperature, exposure to 
moisture, light and air, etc. 

Rancidity should not be confounded with acidity, although rancid oils 
usually are high in acids. Lewkowitsch holds that fatty acids are liberated 
by the action of moisture in the presence of enzymes. If in addition the 
oil is exposed to air and light, the fatty acids are acted on causing rancidity, 
which is detected by taste and smell, although chemically little understood. 
As a rule rancidity develops more readily in liquid oils in which olein 
predominates than in solid fats. To avoid changes samples should be 
kept in a dark, cool place in tight containers. 

Judgment as to Purity of a given oil or fat should not be hastily given. 
It is sometimes comparatively easy to prove the presence and approx- 
imate amount of an adulterant, the various constants all serving to identify 
it without fail. Again, in some cases it is easy to pronounce the sample 
adulterated, without being able to definitely state the exact nature of 
the adulterant. The tests to be employed depend on the particular 
case in hand. Sometimes the determination of two or three constants 
will be sufficiently definite. 

Again, a large number of tests must be made before one can intel- 
ligently form an opinion. It should be borne in mind that skilful manu- 
facturers may adulterate the edible oils and fats with mixtures intended 
to confuse the chemist, and yield on analysis constants that are entirely 
misleading. 

Much information may usually be gained by carefully noting the color, 
taste, odor, and appearance of the sample. 

Filtering, Measuring, and Weighing of Fats. — These manipulations 
naturally present some difficulties in the case of solid fats not encountered 
with liquid oils. 



474 



FOOD INSPECTION /1ND /ANALYSIS. 



A steam- or hot-water-jacketed funnel as represented in Fig. 92 is con- 
venient for filtering fats, or, in the absence of this contrivance for keeping 
the fat in a molten condition, a hot funnel may be employed, the filtering 
being best conducted in a warm closet or oven. 

Portions of the fat for the various determinations may be measured 
off with a pipette while the fat is still hot, but a much better way is to 




Fig. 92.^ — ^Jacketed Funnel for Hot Filtration. 

cool the fat (over ice if necessary), and to weigh the desired amounts in 
the solid state. This can very readily be done by placing a flat platinum 
or other dish on the scale-pan, covering it with a moderately thick, cut 
filter-paper somewhat larger in diameter than the dish and designed to 
lie flat upon it, and taking the tare of both dish and filter. The solidified 
fat, after mixing with a stirring-rod, is transferred in one or more por- 
tions to the middle of the filter, and the exact weighed amount is obtained, 
after which, by carefully handhng the edges of the filter and folding in 
the latter, the fat with the filter may be transferred to a flask or other 
receptacle. 

Specific Gravity.— The specific gravity of liquid oils is most con- 
veniently taken either at room temperature or at 15.5°, being always 



EDIBLE OILS AND EATS. 



475 



best referred to the latter. Either the hydrometer, Westphal balance, 
Sprengel tube, or pycnometer are employed, according to the degree of 
accuracy required. If taken at any other temperature than 15.5°, say 
at room temperature, T, the specific gravity may be computed at 15. 5** 
by the formula 

G = G'+i^(r-i5.5)* 

in which G is the specific gravity at 15.5°, G' the specific gravity at T°, 
and K a factor var\ang with the different oils as follows: 

FACTORS FOR CALCULATING SPECIFIC GRAVITY. 



Oil. 


Correction 
for 1° C. 


Observer. 


Cod-liver oil 


. 000646 
.000658 
.000629 
.000655 
.000620 
.000624 
.000629 


A. H. Allen 
C. M. WetheriU 
C. M. Stillwell 
A. H. Allen 

<i 
<< 


Lard oil 


Olive oil 


Peanut oil 


Rape oil 


Sesame oil 


Cottonseed oil 





Unless the most accurate work is necessary, it is sufficient to assume 
in all cases iv= 0.00064, in which case the formula becomes G=G'-\- 
o.ooo64(r-i5.5). 

In the case of solid fats, it is most convenient to take the specific 
gravity of the melted fat. This may be done at any temperature above 
the melting-point by either of the instruments above described, or at the 
temperature of boiling water by the Westphal balance or pycnometer. 

When the pycnometer is used, it is immersed in a water-bath, the 
temperature of which is well above the melting-point of the fat, say 35° 
or 40°. While still immersed nearly to the neck, it is carefully filled 
\\ith the melted fat and kept in the bath till the fat has acquired the same 
temperature, usually about fifteen minutes. If the pycnometer is pro- 
vided with a thermometer stopper, this wiU serve to indicate the tem- 
perature; otherwise a separate thermometer is inserted in the bath. 
The pycnometer is then removed, cleaned, dried, and cooled to the room 
temperature, at which it is weighed. The factors employed in the above 
formula for calculation of specific gravity of soHd fats at 15.5° are as 
follows : 



* Allen, Com. Org. .Anal., 3d ed., vol. 2, pt. i, p. 



476 



FOOD INSPECTION ANn ANALYSIS. 



FACTORS FOR CALCULATING SPECIFIC GRAVITY. 



Fats. 


Correction 
for 1° C. 


Cocoa butter 


0.000717 
.000675 
.000650 
.000617 
.000674 
.000642 
.000657 


Tallow 


Lard 


Butter fat 


Cocoanut stearin 


Cocoanut oil 


Pabn nut oil 





1 



Either the Westphal balance or the hydrometer may be used directly on 
the melted fat, carefully recording the temperature and calculating as above. 

For making the determination with the Westphal balance at the tem- 
perature of boiling water, the melted fat is contained in a vessel immersed 
in a boihng water- bath, and kept sufficiently long to acquire that tem- 
perature, which is carefully noted. 

A. O. A. C. Method.^ — The pycnometer, being perfectly clean, is 
first weighed with the stopper, after which it is filled with freshly boiled, 
hot, distilled water and placed in a bath of boihng water, where it 
is kept for half an hour, replacing any loss by evaporation in the flask 
with boiling distilled water. The stopper of the pycnometer, previously 
heated at 100°, is then inserted, and the flask removed and wiped perfectly 
dry. It is then allowed to cool nearly to room temperature, and weighed 
on the balance when the temperature is the same as that of the room. 

The flask, being again perfectly clean and dry, is filled while hot with 
freshly melted and filtered hot fat, free from air-bubbles, and kept for 
half an hour in a boiling water-bath, after which the stopper, previously 
heated as before to 100°, is inserted, and the flask taken from the bath 
and wiped dry. It is then allowed to cool and weighed when the tem- 
perature of the room has been reached. 

The specific gravity is calculated by dividing the weight of the fat 
by the weight of the water previously found. 

Having once obtained the weight of the flask and the weight of a 
volume of water contained therein when at boihng temperature, these 
figures can be constantly used without redetermination, if the flask is 
cleaned thoroughly each time. 

Calculation of Proportions of Two Known Oils in Mixture. f — This 
may be roughly accompHshed from the specific gravity of the mixture 
and of the oils known to compose it. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 21. 
t Villiers et Collin, Les Substances Alimentaircs, p. 646. 



FDIRLE OILS Al^D FATS. 



477 



Le. G = specific gravity of mixture, 
D and Z)' = specific gravity of the two oils, 
and A' = 9c oil of specific gravity D. 
\ooiG-D') 



Then A' = 



D-D' 



EDIHLK OILS AND FATS ARRANGED IN ORDER OF SPECIFIC GRA\1TY, 



Specific Gravit y. 



Cocoa butter ' .976 to .950 

-953 " -937 

-952 " -943 

.94^0" .926 

938 " -934 



Mutton tallow. 
Beef " . 

Butter 

Lard 

Poppyseed oil. 
Sunflower oil . 

Com oil 

Cottonseed oil 
Sesame oil. . . . 
Peanut oil. . . . 
Mustard oil. . . 

Olive oil 

Rape oil 



.927 
.926 " 
.926 " 

-925 " 
.924 " 
.921 " 
.920 " 
.918 " 
.917 " 



-924 
-924 
.921 
.922 

-923 
.917 
.916 
.916 
-913 



The Viscosity, or degree of fluidity in the case of edible oik, is of less 
importance than in the case of lubricating oils, and gives little insight 
into the nature or purity of the sample. 

Hence a discussion of various \dscosimeters and their use will not 
be included here, but reference is made to Lewkowitsch* for information 
regarding them. 

The Refractive Index, and the reading on the arbitrary .scale of the 
butyro-refractometer, express in two different and interchangeable terms the 
refraction value, a useful constant of fats and oils and easily determined. 

For the routine examination of fats and oils the butyro-refractometer 
is more convenient than the Abbe refractometer, and the readings obtained 
by the former in.strument are less cumbersome than refractive indices. 

The.se in.struments and details with regard to their manipulation are 
described in Chapter \T. 

The readings on the scale of the butyro-refractometer may be readily 
transformed into refractive indexes and vice versa by table or by means of 
the Leach and Lythgoe slide rule (page 107). Lythgoe'sf table on pp. 
478 and 479 is useful as showing readings on the butyro-refractometer of 
all the edible oils and fats at various temjjeratures. 

* Chemical .\nalysis of Oils and Fats, 3d ed., 1904, pp. 197-209. 
f Tech. Quai^srly, i6, 1903, p. 222. 



^78 



FOOD INSPECTION AND ANALYSIS. 



CALCULATED READINGS ON BUTYRO-REFRACTOMETER OF EDIBLE 

OILS AND FATS. 



Temp. 
C. 



45 -o 

44-5 
44-0 
4,3-5 
43-0 
42-5 

42.0 

41-5 
41.0 

40-5 
40.0 

39-5 
39-0 

38-5 
38.0 

37-5 

37-0 
36-5 
36.0 

33-5 
35-0 

34-5 
34-0 

33-5 

32 5 

32.0 
31-5 
31-0 
30-5 
30.0 

29-5 

2q.o 
28.5 
28.0 
27-5 

27.0 
26.5 
26.0 

25-5 
25.0 



Cocoanut 


Oil. 


31.6 


31-9 


32.2 


32-4 


32-7 


52-9 


33-2 


33-5 


33-7 


34-0 


34-3 


34-5 


34-8 


35-0 


35-3 


35-5 


35-8 


.36.1 


36.3 


36.6 


36-9 


37-1 


37-4 


37-6 


37-9 


38.1 


38-4 


^8.6 


38-9 


39-2 


39-5 


39-7 


40.0 


40-3 


40.5 


40.8 


41.0 


41-3 


41-5 


41.8 


42.0 



Butter.* 



Beef 

Stearin. 



41-5 


41.8 
42.0 
42.3 

42.6 

42.9 


43-1 
43-4 
43-7 
43-9 
44-2 


44-5 
44-8 
45-0 
45 - 3 
45-6 


45-9 
46. 1 
46.4 
46-7 
47-0 


47-2 
47-5 
47-8 
48.1 
48.3 


48.6 
48.9 
49-2 


49-5 
49-8 


50-0 
50-3 
50-5 
50.8 

51-1 


51.4 

51-6 

51-9 
52.2 

52-5 



41.9 

42.2 
42-4 

42.6 

42-9 

43-2 

43-5 
43-7 
44.0 
44-2 
44-5 



Cacao 
Butter. 



43-7 

44.0 

44-2 
44-5 
44-8 
45-0 

45-3 
45-6 
45-9 
46. 1 

46-4 

46.6 
46.8 
47-1 
47-4 
47-6 

47-9 
48.2 

48-5 
48-7 
49.0 



Bgef 
Tallow. 



44-1 

44-3 
44-6 
44-8 
45-1 
45-4 

45-6 
45-8 
46.1 

46-3 
46.6 

46. S 

47.7 

47-4 
^7-6 
47-8 

48.1 

48.3 
48.6 
48.8 
49- r 



Lard 
Stearin. 



44-9 

45-1 
45 - 5 
45-7 
46.0 

46.3 

46.5 
46.8 

47.0 

47-3 
47.6 



47- 
48. 
48. 
48, 
48. 



49-2 
49-4 
49-7 
50.0 
50.2 



Beef 

Oleo. 



45-0 

45-3 
45-6 

45-9 
46. 1 

46.4 

46-7 

47.0 

47-3 
47-6 
47-8 

48. 1 
48.4 
48-7 
48.9 
49-2 

49-5 
49.8 
50.0 

50-3 
50.6 

50-9 
51-2 
5 T ■ 5 
51-7 



52-3 
52.6 
52-8 

53-4 

53-7 
53-9 
54-1 
54-4 

54-7 

55-0 
55-2 
55-5 
65-8 
66.1 



Lard.t 



48.2 



48.4 
48.7 
49-0 
49-3 
49-6 

49-9 

50.1 
50.4 

50-7 
51-0 

51-6 
51.9 
52-1 
52-4 

52-7 
53-0 

53-6 
53-9 



54-4 
54-7 
55-0 
55-3 

55-6 
55-9 
56-1 
56-4 

56.7 



57-3 
57-6 



58.4 

58-7 
59.0 

59-3 
59-6 



* Butter readings by Zeiss. 

t Lard readings by Hefelmann. 



EDIBLE OILS AND FATS. 



479 



CALCULATED READINGS— (Ccw/tMMcd). 



Ternp. 
C. 


Olive 
OU. 


Peanut 
OU. 


Cotton- 
seed 
Oil. 


Rape- 
seed 
Oil. 


Sesame 
Oil. 


Yellow 

Mustard 

Oil. 


Black 

Mustard 
Oil. 


Sun- 
flower 
Oil. 


Com 
Oil. 


Poppy- 
seed 
Oil. 


35-0 


57-0 


59-8 


61.8 


62.1 


62.3 


63.0 


64.2 


64-5 


65.0 


'•5-5 


34-5 


57-2 


60.0 


62.1 


62.4 


62.5 


63-3 


64-5 


64.8 


65-3 


6:^.8 


74.0 


57-4 


60.^ 


62.3 


62.7 


62.8 


63.6 


64.8 


65.1 


65.6 


66.1 


33-5 


57-7 


60. (5 


62.5 


63.0 


63.1 


63-9 


65.1 


65-4 


65-9 


66.4 


3?,-° 


58.0 


60.9 


62.8 


63-3 


63-4 


64.1 


65-3 


65-7 


66.2 


66.7 


3^-5 


58-3 


61. 1 


63.0 


63.6 


63-7 


64.4 


65.6 


66.0 


66.5 


67.0 


32.0 


58.5 


61.4 


63.2 


63.8 


64.0 


64.7 


65-9 


66.3 


66.8 


67-3 


31-5 


59-0 


61.7 


63.6 


64. 1 


64-3 


65.0 


66.2 


66.6 


67.1 


67.6 


31.0 


59-2 


62.0 


64.0 


64.4 


64.6 


65-3 


66.5 


66.9 


67-4 


67.9 


30-5 


59-5 


62.2 


64.2 


64-7 


64.9 


65.6 


66.8 


67.2 


67-7 


68.2 


30.0 


59-9 


62.5 


64-5 


65.0 


65.1 


65.8 


67.0 


67-5 


68.0 


68.5 


29-5 


60.1 


62.8 


64.9 


65-3 


65.4 


66.1 


67-3 


47-7 


68.2 


68.7 


29.0 


60.3 


63.1 


65.1 


65.6 


65-7 


66.4 


67.6 


68.0 


68.5 


69.0 


28.5 


60.6 


63-3 


65-3 


65-9 


66.0 


66.7 


67.9 


68.3 


68.8 


69-3 


28.0 


60.9 


63.6 


65-7 


66.1 


66.2 


66.9 


68.1 


68.6 


69.1 


69.6 


27-5 


61. 1 


63-9 


66.0 


66.4 


66.5 


67.2 


68.4 


68.9 


69.4 


69.9 


27.0 


61.5 


64-2 


66.5 


66.7 


66.8 


67-5 


68.7 


69.2 


69.7 


70.2 


26.5 


62.0 


64.4 


67.0 


67.0 


67.1 


67.8 


69.0 


69-5 


70.0 


70-5 


26.0 


62.2 


64-7 


67-3 


67-3 


67.0 


68.0 


69.2 


69.8 


70-3 


70.8 


25-5 


62.4 


65.0 


67-5 


67.6 


67.7 


68.3 


69-5 


70.1 


70.6 


71. 1 


25.0 


63.0 


65-3 


67.9 


67.8 


67.9 


68.6 


69.8 


70.4 


70.9 


71-4 


24.5 


63-3 


65-5 


68.2 


68.1 


68.2 


68.9 


70.1 


70^7 


71.2 


71-7 


24.0 


63.6 


65.8 


68.5 


68.4 


68.:; 


69.2 


70.4 


71.0 


71-5 


72.0 


23-5 


63-9 


66.1 


68.8 


68.7 


68.8 


69-5 


70.7 


71-3 


71.8 


72-3 


23.0 


64.2 


66.4 


69.1 


69.0 


69.1 


69.7 


70.9 


71.6 


72.1 


72.6 


22.5 


64-5 


66.6 


69.4 


69-3 


69.4 


70.0 


71.2 


71.9 


72-4 


72-9 


2i.O 


64.8 


66.9 


69.7 


69.7 


69.7 


70-3 


71-5 


72.2 


72-7 


73-2 


21-5 


65.1 


67.1 


70.0 


70.0 


70.0 


70.6 


71.8 


72-5 


73-0 


73-5 


21.0 


65-4 


67.4 


70-3 


70-3 


70-3 


70.9 


72.1 


72.8 


73-3 


73-8 


20.5 


65-7 


67.7 


70.6 


70.6 


70-S 


71.2 


72.4 


73-1 


73-6 


74.1 


20.0 


66.0 


68.0 


70.9 


70.8 


70.8 


71.4 


72.6 


73-4 


73-9 


74-4 


19-5 


66.3 


68.2 


71.2 


71. 1 


71. 1 


71.7 


72.9 


73-6 


74-1 


74-6 


19.0 


66.6 


68.=; 


71-5 


71.4 


71-4 


72.0 


73-2 


73-9 


74-4 


74-9 


18.5 


66.9 


68.8 


71.8 


71.7 


71.7 


72-3 


73-5 


74-2 


74-7 


75-2 


18.0 


67.2 


69.1 


72.1 


72.0 


72.0 


72.6 


73-8 


74-5 


75-0 


75-5 


17-5 


67-5 


69-3 


72-4 


72-3 


72-3 


72.9 


74.1 


74-8 


75-3 


75-8 


17.0 


67.8 


69.6 


72.7 


72.6 


72-5 


73-1 


74-3 


75-1 


75-6 


76.1 


16.5 


68.1 


69.9 


73-0 


72.9 


72.8 


73-4 


74-6 


75-4 


75-9 


76.4 


16.0 


68.4 


70.2 


73-3 


73-2 


73-1 


73-7 


74-9 


75-7 


76.2 


76.7 


15-5 


68.7 


70-5 


73-6 


73-5 


73-4 


74.0 


75-2 


76.0 


76-5 


77.0 


15.0 


68.9 


70.8 


73-8 


73-8 


73-7 


74-3 


75-5 


76.3 


76.8 


77-3 



4So 



FOOD i\sri:(:Ti()N a\'I) an/1 lysis. 



Melting-point. ~A \)'\vcv of small glass tubing is drawn out to a ca- 
pillary oi)C'n at both ends, and this is inserted into a beaker of the fat, melted 
at a temjjerature slightly above its fusing-point. A portion of the melted 
fat being drawn uj) into the capillary, the latter is removed and the fat 
allowed to solidify spontaneously. After an interval of not less than 
twelve hours, the capillary is attached by a rubber band to the stem of 
a delicate thermometer (preferably cajnible of being read to tenths of a 
degree), the portion of solidified fat being opposite the thermometer bulb. 
A test-tube containing water is held in the neck of a flask in such a man- 
ner as to be immersed in water contained in the flask, as shown in Fig. 
93, the flask being held on the ring of a stand, with wire gauge inter- 
posed between flask and flame. The thermometer with attached capil- 
lary is then held immersed in ihe water of the test-tube and below the 





Fig. 93. Fig. 94. 

Fig. 93, — Apparatus for Determining Melting-point. Capillary tube with enclosed 
fat shown on the right, enlarged. 

Fig. 94. — Reichert Flask with Card Inserted for Quick Evaporation. 

level of the water in the flask, as shown. The water in the flask is then 
heated very gradually, so that the rise of temperature as shown by the 
thermometer does not exceed 0.5° C. per minute, the exact temperature 
at which fusion of the fat occurs being recorded as the melting-point. 

The flame is then removed, and the temperature at which the fat 
solidifies is noted as the solidifying-point. 



EDIBLE OILS AND FATS. 



481 



The mean of two or three determinations is usually taken as the true 
melting and solidifying-points, 

Reichert-Meissl Process for Volatile Fatty Acids.— This process 
has undergone various modifications from time to time. Reichert origi- 
nally used 2.5 grams of fat, but Meissl, who improved the process, used 




Fig. 95. — Apparatus for Reichert-Meissl and Poienske Distillation. 



5 grams, so that the Reichert-Meissl number is now expressed on the 
basis of 5 grams of fat. The method is conveniently carried out as 
follows : 

Five grams of the fat are transferred to a dry, clean Erlenmeyer flask 
of about 300 cc. capacity, 10 cc. of 95% alcohol are added, and 2 cc. of 
sodium hydroxide solution (prepared by dissolving 100 grams of sodium 
hydroxide in 100 cc. of water). The flask with its contents is then heated 



482 FOOD INSPECTION AND ANALYSIS. 

on a water-bath with a funnel in the neck, which satisfactorily replaces 
the return-flow condenser originally prescribed. The heating is con- 
tinued with occasional shaking till saponification is complete. This 
stage of the process is indicated by the appearance of the solution, which 
is then perfectly clear and free from fat globules. 

The condenser-funnel being removed, the contents of the flask are 
next evaporated by continued heating over the bath to dr}mess. This 
may be hastened by inserting a card in the neck of the flask, as shown 
in Fig. Q4, thus starting a circulatory movement to the air through the 
flask. 

The dry soap thus formed is then dissolved by warming on the water- 
bath with 135 cc. of added water, shaking the flask occasionally. After 
cooling, 5 cc. of dilute sulphuric acid (200 parts sulphuric acid in i liter 
of water) are added, and the fatty acid emulsion formed is melted by 
heating the flask on the water -bath, the flask being corked during the 
heating. The fatty acids are completely melted when they form an oily 
layer on the surface of the solution. 

Scraps of pumice stone joined by platinum wires are next placed in 
the flask to prevent bumping, and the flask is properly connected with 
the condenser for distilling, as shown in Fig. 95. A flask graduated at 
no cc. is used as a receiver, the funnel placed therein being provided 
with a loose tuft of absorbent cotton to serve as a filter. The distilla- 
tion is conducted by so grading the heat that the receiving flask is 
filled with the distillate in about thirty minutes. 

Finally the entire distillate is titrated with decinormal sodium hydrox- 
ide, using 0.5 cc. of a solution of phenolphthalein as an indicator. The 
number of cubic centimeters of decinormal alkali required to neutralize 
the acidity of the distillate from 5 grams of the fat in the manner described 
expresses what is known as the Reichert-Meissl number. 

Lefjmann and Beam's Modification* — Five grams of the fat placed in 
the flask are treated with 20 cc. of a solution of soda in glycerin (20 cc. 
of a 50% solution of sodium hydroxide in 180 cc. of glycerin), heating the 
flask tin the contents are completely saponified. The solution becomes 
perfectly clear, showing complete saponification in about five minutes, 
after which 135 cc. of water are added to the clear soap solution, at first 
drop by drop to prevent foaming; 5 cc. of the dilute sulphuric acid are 
then added, and the distillation conducted at once without first melting 
the fatty acids. 

* Leffmann and Beam, Select Methods of Food Analysis, p. 146. 



EDIBLE OILS AND FATS. 483 



EDIBLE OILS AND FATS IX THE ORDER OF THEIR REICHERT-MEISSL. 

NUMBER. 





Lowest. 


Highest. 


Average. 


Butter 

Cocoanut oil 


24.5 
6.65 
0.20 
1-32 

0.70 
0.58 


32 

7-8 

0.80 

5-0 

1.20 
0.90 


28.25 
7-2 

0-5 


Corn oQ 

Lard 


;.i6 
1. 10 
0-95 
0-95 
0.74 
0.60 
0-5 


Sesame oil 


Olive oil 





Polenske Number.* — This number represents the volatile fatty acids 
insoluble in water, and is of value in detecting cocoanut oil in butter and 
other fats. The details of apparatus and manipulation here described 
should be closely adhered to in order to secure comparable results. Both 
the Reichert-Meissl and the Polenske number may be determined in 
one weighed portion of the fat. 

Place 5 grams of the clear filtrated fat in a 300-cc. Jena flask, adfl 20 
grams of glycerine and 2 cc. of a 5o9c solution of sodium hydro.xide. 
Heat the flask on a wire gauze until the contents are completely saponified, 
which requires about 5 minutes, and is indicated by the clearing up of the 
liquid. AMiile still hot add 90 cc. of boiled water, at first drop by drop to 
prevent foaming, and shake until the soap is dissolved. The solution 
should be completely clear and almost colorless. Rancid or oxidized fats 
that yield a brown soap solution should not be examined. 

To the soap solution, warmed to 50°, add 50 cc. of dilute sulphuric 
acid (25 cc: i hter) and 0.5 gram of granulated pumice stone with grains 
T mm. in diameter, then connect with the distilling apparatus shown in 
Fig. 95. Distil over a 0.5 mm. mesh copper gauze, using a Bunsen flame 
so regulated as to give a distillate of no cc. in 19-20 minutes, and a stream 
of water that will cool the distillate to about 20-23° The room should 
have a temperature of about 18-22°. As soon as no cc. have come over, 
replace the flask by a 25-cc. measuring cylinder. 

Without mixing the distillate place the flask for 10 minutes in water 
at 15°, so that the no cc. mark is about 3 cm. below the surface of the 
water. After the first five minutes, gently move the neck of the flask in 

* Polenske, 2^its. Unters. Nahr. Genuss., 7, 1904, p. 274. Fritsche, ibid., p. 193. 



484 FOOD INSPECTION AND ANALYSIS. 

the water so that the fatty acids floating on the surface come in contact 
with the glass, noting at the end of 10 minutes the condition of these acids. 
If the butter is pure, the floating acids are either solid or form a half solid 
turbid mass, according as the Reichert-Meissl number is high or low; 
if it is adulterated with 10% or more of cocoanut oil, they form transparent 
oil drops. Stopper the iio-cc. flask, mix by inverting 4 or 5 times, avoiding 
violent shaking, filler through an 8-cm. dry filter fitted close to the funnel, 
and titrate 100 cc. of the liquid with tenth-normal barium hydroxide 
solution, thus obtaining the Reichert-Meissl number. 

After the last drop of distillate has passed through the filter, wash 
with three 15 cc. portions of water, each of which has previously been 
used to rinse the condenser tube, the measuring cylinder and the no cc. 
flask. Then repeat this treatment, using 15 cc. portions of neutral 90% 
alcohol. Titrate the united alcoholic washings with tenth-normal barium 
hydroxide solution, using phenolphtalein as indicator. The number of 
cc. required is the Polenske number. 

The following results illustrate the value of the method : 

Reichert-Meissl Polenske 
Number. Number. 

31 samples of butler (Polenske) 23.3-30.1 1.5-3.0 

4 samples of cocoanut oil (Polenske) 6.8-7.7 16. 8-17. 8 

Oleomargarine (.Arnold) 0.5 o. 53 

Lard (Arnold) 0.35 0.5 

Tallow (Arnold) 0.55 0.56 

Determination of Soluble and Insoluble Fatty Acids. — A. O. A. C. 

Method.'^ — Soluble Acids. — Five grams are weighed out and trans- 
ferred to an Erlenmeyer flask of the same size and in the same manner 
as that used for the Reichert-Meissl process. 50 cc. of alcoholic 
potash solution are added (40 grams of potassium hydroxide in i liter 
of 95% redistilled alcohol) and the fla.sk, j^rovided with a return-flow 
condenser, is heated on the water-bath till saj^onification is complete, 
as evidenced by the clear solution free from fat globules. The 
alcoholic solution of potash is preferably measured from a pipette, 
from which it is allowed to drain for a noted interval of time, say thirty 
seconds. 

After complete saponification, the condenser is removed and the 
alcohol is evaporated by further heating. One or more blanks are pre- 

* U. S. Dept. of Agric, Div. of Chem., Bui. 46, p. 47; Bui. 107 (rev.), p. 138. 



EDI RLE OILS AND FATS. 485 

pared at the same time, using the same 50-cc. pipette for measuring, and 
applying the same time limit for draining the pipette. The blanks are 
first titrated, after evaporation, with half-normal hydrochloric acid, 
using phenolphthalein as an indicator. Then add to the flask contain- 
ing the fatty acids i cc. more of the half- normal acid than is found neces- 
sar}'to neutralize the alkali in the blanks, after which the flask is again 
heated with a funnel in the neck till the fatty acids have completely sepa- 
rated in a layer on top of the solution. Then cool the flask in ice water 
till the fatty acids are sohdified, after which decant the liquid portion 
through a filter, previously dried in the oven and weighed, into a liter 
flask, keeping the solid mass of fatty acids intact. Next add 200 or 300 
cc. of hot water to the flask containing the fatty acids, and again melt 
over the water-bath till they collect as before on top, having again inserted 
the funnel to act as a condenser, and occasionally shaking the contents 
of the flask during heating. Cool as before in ice water, after which 
again decant the liquid from the solid mass through the same filter into 
the liter flask. Repeat this process of washing, melting, cooling, and 
decanting three times, receiving all the wash water through the same 
filter in the same flask. Make up the washings with water to the liter 
mark, and, after mixing, two portions of 100 cc. each are titrated with 
tenth-normal sodium hydroxide, using phenolphthalein for an indicator. 
Each reading is multiplied by ten to represent the total volume, and the 
figure thus obtained represents the number of cubic centimeters of tenth- 
normal alkali necessary to neutrahze the acidity of the soluble fatty acids, 
together with the excess of half-normal acid used, amounting to i cc. 
This I cc. of half-normal acid corresponds to 5 cc. of tenth-normal alkali, 
hence 5 cc. are to be deducted from the total number of cubic centimeters 
required for the titration, the corrected figure thus obtained being multi- 
plied by the factor 0.0088, which gives the weight of soluble fat acids in 
the 5 grams of the sample, calculated as butyric acid. 

Insoluble Acids. — Transfer the fatty acids left in a cake in the flask 
from the separation of the soluble acids, to a weighed glass evaporating 
dish, using strong alcohol to wash them out thoroughly. Dry the filter used 
in the separation, transfer it to an Erlenmeyer flask, and thoroughly 
wash it with strong alcohol, transferring all the washings to the dish. The 
alcohol is then evaporated by placing the dish on the water-bath, after 
which it is dried for two hours in the air-oven at 100°, cooled in the desic- 
cator, and weighed. After once heating for two hours, cooling and ueigh- 
ing, heat again for half an hour, cool, and weigh. If a considerable loss 



486 FOOD INSPRCTION AND AN /I LYSIS. 

in weight is found, heat for an additional half-hour. It Ls best, "however, 
to avoid too prolonged heating, lest oxidation of the fatty acids should 
produce an increase in weight. 

Hehner^s Method. — Transfer the fatty acids left in the original Erlen- 
meycr flask to the thoroughly wet, tared filter, washing out the ilask 
with hot water, thus Ijringing all the fatty acids upon the filter, which, 
if of good quality and thoroughly wet beforehand, will retain them. If, 
however, oily particles are noticed in the filtrate, they may be solidified 
by cooUng in ice water, and afterwards removed by a glass rod and trans- 
ferred to the filter. After draining dry, the funnel is immersed in cold 
water to soUdify the fatty acids, and the filter containing them is trans- 
ferred to a weighed dish, which is dried for two hours in the oven at ioo°, 
cooled in the desiccator, and weighed, subtracting the weight of the 
dish and filter. 

EDIBLE OILS AND FATS ARRANGED IN ORDER OF INSOLUBLE FATTY 

ACIDS. 

Mustard oil 96. 2 to 95 . i 

Cottonseed oil 96 "95 

Corn oil 96 "93 

Lard 96 "93 

Peanut oil 95-8 

Sesame oil 95-7 

Beef tallow 95 - ^ 

Mutton tallow 95-5 

Poppysecd oil 95-2 "94.9 

Rape oil 95 • i 

Sunflower oil 95 

Olive oil 95 

Cocoa butter 94-6 

Cocoanut oil 90 " 88.6 



Butter 80.8 " 86. 



Saponification Number. — KoeUstorjef s Method. — By the saponifi- 
cation number i:^ meant the number of miUigrams of potassium hydroxide 
necessar}' to completely saponify i gram of the fat. Between i and 2 
grams of the fat are transferred in the usual manner (see p. 474) to an 
Erlenmeyer flask, and 25 cc. of the alcoholic potash solution (40 grams of 
potassium hydroxide free from carbonates in i liter of 95% alcohol 
redistilled after standing for some time with potassium hydroxide) are 
added with a graduated pipette, which is allowed to drain for a noted 
period of time, say thirty seconds. The determination should preferably 



EDIBLE OILS AND FATS 



487 



be marie in duplicate. Conauct me ^^aponitication as in the case of the 
soluble fatty acids by heating on the water-bath. After saponification, 
remove from the bath, cool, and titrate with half-normal hydrochloric acid, 
using phenolphthalein as an indicator. Titrate also several blanks in 
which 25 cc- of the alcoholic potash solution are measured out with the 
same pipette as before, and aUow to drain for the same amount of time. 
Subtract the number of cubic centimeters of half-normal acid necessary 
to neutralize the alkali in the case of the saponified fat from that necessary- 
to neutralize the blank, multiply the result by 28.06, and divide the 
product by the number of grams of fat taken. 

EDIBLE OILS AND FATS ARRANGED IN ORDER OF THEIR SAPONIFICA- 
TION NUMBER. 



Cor.'janut oil 

Bu-L-f^T 

C>j^,oa hutter. . 

E-r*:' tiikx- 

Lard 

Lard ofl. 

Cottonseed stearin 

Poppy seed otl 

Conton»eefi ofl. 

Peaxiut oiL 

Sun tioTB-er oil 

Sesame otL 

Olive oiL 

Corr: oiL 

Rape ofL 

Elaric rr.'i.^tani oil . 
Whiif. rr.Tiitard oiL 



—-■-■- 


JCazi-n:~i 


246,2 


26S.4 


225 


230 


192 


202 


IM-2 


200 


195-3 


196.6 


195 ^ 


196 


194-6 


195 -I 


190 


ri>^ 


191 


196.6 


190 


197 


193 


19* 


X87-6 


192,4 


185 


196 


x8S 


193-4 


170-2 


179,2 


174 


174-6 


170-3 


174-6 



Msa.r 



257-3 

227,5 

197 

196,6 

196 

195-5 

194,4 

£9* 

193-8 

193-5 

193-5 

1^,6 

191-5 

190,7 
174-6 

174-3 
172-4 



The Iodine Absorption Number, — This determination Is based on 
th^ 'Vf:Il-i-:r.o-//a property of the unsaturated fatty acids to absorb a fixed 
amo :n: .:' i^xline imder given conditions of time^ strength of reagent, etc 

Hobl's Method.* — ^The following reagents are necessary: 
ij Iodine Solution, made by dissolving 26 grams of p^ure iodine in 
500 cc- of 959c alcohol, and, separately, 30 grams of mercuric chloride 
in 500 cc of the same s.rength of aloAoL Filter the latter solution, 
if necessary, and mii the two together, allowing the mixture to stand 
at least twelve hours before using, 

(2) Decinormal Thiosulphate Soiuiion, made by dissolving 24-6 grams 
of the freshly powdered, chemically pure sak in water, and making up 
to I liter. 



*,\, O. ,\. C. yUthod, L. ■•. Dept. ot .\j5rir.. ft 
(rev,), p. 136, 



of Chetn., Bal, 65^ p. 24; Bal, 107 



483 FOOD INSPECTION /iND ANALYSIS. 

(3) Starch paste, prepared by boiling i gram of starch in 200 cc. of 
water for ten minutes, then cooling. 

(4) Potassium Iodide Solution, made by dissolving 150 grams of the 
salt in water, and making up the volume to i liter. 

(5) Potassium Bichromate Solution for standardizing the thiosulphate, 
made by dissolving 3.874 grams of chemically pure potassium bichromate 
in distilled water, and making up the volume to i liter. 

The sodium thiosulphate solution is standardized as follows: 20 cc. 
of the potassium bichromate solution are introduced into a glass-stoppered 
flask together with 10 cc. of potassium iodide and 5 cc. of strong hydro- 
chloric acid. Then slowly add from a burette the sodium thiosulphate 
solution, till the yellow color of the solution has nearly disappeared, after 
which a little of the starch paste is added, and the titration carefully con- 
tinued to just the point of disappearance of the blue color. The reaction 
which takes place is as follows: 

K2Cr20,+ i4HCl+6KI = 2CrCl3-f8KCl+6I+7HA 

The equivalent of i gram of iodine in terms of the thiosulphate solu- 
tion is found by multiplying the number of cubic centimeters of the latter 
solution required for the above titration by 5. 

If, for example, 16.4 cc. of the thiosulphate solution are required 
for 20 cc. of the bichromate solution, then i gram of iodine is equivalent 
to 16.4X5 = 82.0 cc. of sodium thiosulphate solution, or i cc. of the thio- 
sulphate solution =-/^ = o.oi22 gram of iodine, i cc. of exactly deci- 
normal thiosulphate is theoretically equivalent to 0.0127 gram of iodine. 

The thiosulphate solution may also be standardized by means of 
iodine. A short tube closed at one end is tared, together with another 
tube of such a size as to fit over the lirst. Into the inner tube are 
introduced about 0.2 gram of resublimed iodine and the tube heated 
until the iodine melts, after whicli it is closed by the second tube and the 
whole cooled in a desiccator and weighed. The iodine is dissolved in 
10 cc. of 10% potassium iodide solution, the solution diluted with water, 
and the thiosulphate solution added with constant stirring until only a 
yellow color remains. Starch paste is then added, and the titration con- 
tinued until the blue color disappears. 

Method of Procedure. — Place i gram of the solid fat, or from 0.2 to 
0.4 gram of oil, in a glass-stoppered flask or bottle of 300 cc. capacity. 



EDIBLE OILS AND FATS. 489 

In the case of oils, this may conveniently be done by difference, weigh- 
ing first a small quantity of the oil in a beaker with a short piece of glass 
tubing to serve as a pipette, transferring a number of drops of the oil 
from the beaker to the bottle, and again weighing the beaker and contents. 
The number of drops of oil required for the desired weight is first ascer- 
tained experimentally. 

The material may also be conveniently and accurately weighed in 
small, flat bottomed cylinders of glass about 10 mm. in diameter and 15 
mm. high, which may be made by cutting off" so-caUed " shell vials." 
Fats are introduced while melted, the weight being taken after cooling. 
The cvlinder and fat are transferred together by means of forceps to 
the glass-stoppered bottle. 

Dissolve the oil in 10 cc. of chloroform, and after solution has taken 
place, add 30 cc. of the iodine solution, shake, and set the flask in a dark 
place for three hoiirs, shaking occasionaUy. \\Tien ready for the titra- 
tion, add 20 cc. of the potassium iodide solution (the purpose of which 
is to keep in solution the mercuric iodide formed, which would othen%'ise 
precipitate on dilution) and 100 cc. of distilled water. Titrate the 
excess of iodine bv the thiosulphate solution, which is slowly added 
from a burette till the yeUow color has nearly disappeared, then add a 
little starch paste, and finally thiosulphate solution drop by drop imtil the 
blue color of the iodized starch is dispelled. Near the end of the reaction 
the flask should be stoppered and \-igorously shaken, in order that all 
the iodine may be taken up, and sufficient thiosulphate should be added 
to prevent a reappearance of any blue color in five minutes. 

Two blanks are conducted at the same time and in similar flasks or 
bottles, in exactly the same manner as in the case of the above titration, 
except that the fat is omitted. This is to get the true value of the iodine 
solution in terms of the thiosulphate solution. 

Suppose, for example, in the case of the blanks, 30 cc. of the iodine 
solution required in one instance 46.1 cc. of sodium thiosulphate solution, 
and in the other 46.5 cc. The mean is 46.3. Suppose 15.1 cc. of thio- 
sulphate solution were reqtiired for the excess of iodine remaining over 
and above that absorbed by i gram of the fat in the above process. Then 
the thiosulphate equivalent to the iodine absorbed by the fat would be 
46.3— 15.1 = 31.2 cc, and the per cent of iodine absorbed would be 31.2 X 
0.0122X100 = 38.06. 



490 



FOOD INSPECTION AND ANALYSIS. 



EDIBLE OILS AND FATS ARRANGED IN ORDER OF THEIR HUBL NUMBER. 



Lowest. 



Highest. 



Average. 



Poppyseed oil ... . 
Sunflower oil . ... 

Corn oil 

Cottonseed oil . . . 

Sesame oil 

Rape oil 

Black mustard oil 
White mustard oil 

Peanut oil 

Cottonseed stearin 

Olive oil 

Lard oil 

Lard 

Beef tallow 

Mutton tallow . . . 
Cocoa butter .... 

Butter 

Cocoanut oil 



ii8 

III. 2 

io8 

103 

94 
96 
92.1 

83 

88.7 

79 
56 
46 

35-4 
32-7 
32 

25-7 
8 



143-3 

130 
no 

115 
105 
no 

97-7 
103 
10;. 8 



70 

47-5 
46.2 

41-7 

37-9 

9-5 



138 
125-7 
120.6 
109.5 
109 
99-5 



58 

41.4 
39-5 
34.9 

8.7 



The Hiibl method has long been ahnost universally used for esti- 
mating the per cent of iodine absorbed, but is open to serious objections, 
chief of which are the tendency of the iodine solution to lose strength, 
and the length of time required to insure saturation of the oil with the 
iodine. 

Of late two other methods have come into prominence, viz., the 
Wijs and the Hanus. The reagents in both these methods hold their 
Strength for months without change, and the time required for carrying 
out the reaction in the case of most of the edible oils and fat^- is very 
short. 

Of the three methods, that of Hanus has the advantage of greatest 
simplicity in the composition and preparation of the chief reagent. 

Tolman and Munson* have shown that with oils and fats having 
iodine numbers below 100, the three methods give practically identical 
figures, while with oils having high iodine numbers, the Wijs and Hanas 
methods give higher results than the Hiibl, but are doubtless more nearly 
correct. 

The following are comparative results of the three methods:* 



Jour. .\m. Chem. Soc, 25 (1903), p, 244. 



EDIBLE OILS AND FATS. 



491 



2;< 






>2^ 



3g« 
C 3 o 



C lu & 






I 

2 
I 

4 

2 

3 
S 

2 

I 
3 

I 

3 



Cocoanut oil 

Butter — minimum 

maximum, 

Oleo oil 

Oleomargarine — minimum 

maximum, 
Lard oil — minimum 

maximum 
Olive oil — minimum 

maximum 

average . . 
Peanut oil — minimum 

maximum 
Mustard oil — minimum 

maximum 
Rape oil — minimum 

maximum 

Sunflower oil 

Cottonseed oil — minimum 

maximum 

Sesame oil 

Corn oil — minimum 

maximum 
Poppyseed oil — minimum 

maximum 



8-93 


9- 


34-8 
35-3 


35- 
36. 


42.6 


43- 


52.5 
66.3 


52- 
66. 


69-3 


70. 


73-7 


74- 


79-2 
89.8 
84.0 


79- 
91. 

85- 


94-5 


95- 


107.7 
98.4 


109. 
104. 


113. 


118. 


100.2 


104. 


101.3 


105. 


106.4 


109. 


103.8 
106.2 


105. 
107. 


106.4 


107. 


119. 


122. 


123.3 


129. 


133-4 


135- 


134-9 


139- 



■05 

■9 

.2 

•5 
-9 



8.60 
35-4 
35-3 
43-3 
52.0 
64.8 
69.8 

73-9 
80.6 
90.0 
84.6 

94-1 
107.7 
103.8 
116. 8 
102.8 
105.2 
107.2 
105.2 
107.8 
106.5 
119. 6 
126.0 
132.9 
138-4 



-f 0.12 

4-1.1 

4-0.9 

-t-0.9 

-f 0.4 

-0.3 

-fl.2 
+ 0.7 
4-0.7 

-fi.6 

+ 1-3 
4-0.7 
-f 1.8 
+ 5-9 
+ 5-2 
+ 3-9 
+ 4-4 
4-2.8 

+ 1-5 
+ 1.1 
4-0.6 
+ j.o 
+ 5-8 
4-1.8 
+ 4-2 



-0-33 
4-0.6 
-f 0.0 
4-0.7 
-0-5 



-1-5 

+ 0.5 
4-0.2 
+ 1.4 

-fO.2 
4-0.6 
— O.I 
4-0.0 

+ 5-4 
+ 3-8 
4-2.6 
+ 3-8 
4-0.8 

+ 1-4 
4-1.6 
-1-0. 1 
4-0.4 
-1-2.7 
-0-5 
+ 3-5 



Hanus' Method.* — Reagents. — Iodine Solution. — Dissolve 13.2 grams 
of pure iodine in i liter of |)ure glacial acetic acid (99%), and to the cold 
solution add 3 cc. of bromine, or sufficient to practically double the halo- 
gen content when titrated against the thiosulphate solution, but with 
the iodine slightly in excess. 

Decinormal Thiosulphate Solution, Starch Paste, and Potassium Iodide 
Solution, as in Hiibl's method. 

Method of Procedure.— Proceed as in Hiibl's method, substituting 
30 cc. of the Hanus iodine reagent for that of Hiibl, stirring the solu- 
tion before adding the water, and, instead of adding 20 cc. of the 
potassium iodide solution, use only 10 cc. 



* Zeits. f. Unters. Nahr. u. (jenuss., 4 (1901), p. 913. Also Hunt, Jour. Soc. Chem Ind. 
21 (1902), p. 454; U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 136. 



4^2 FOOD INSPECTION AND ANALYSIS. 

Only half an hour is required for full saturation of the oil by the- 
iodine in the Hanus method, as against three hours in the Hiibl. In 
case of the non-dr}'ing oils and fats, the reaction takes place in from 
eight to fifteen minutes, though it is best to let the flask set for half an 
hour at least, in all cases. With oils having an iodine number in excess 
of ICG, Tolman and Munson recommend one hour's standing. 

On account of the high coefficient of expansion of acetic acid, care 
should be taken that the temperature is the same when the iodine solu- 
tion is measured for the blank and for the determination, as otherwise 
a serious error may be introduced. 

Wijs's Method.* — Reagents. — Iodine Solution. — Dissolve 13.2 grams 
of pure iodine in i liter of pure glacial acetic acid, and pass through the 
larger portion of this solution a current of carefully washed and dried 
chlorine gas f until the solution is practically decolorized. Finally add 
enough of the original solution of iodine in acetic acid to restore the 
iodine color, so that there is a slight excess of iodine. 

Hunfs Modified Iodine Solution. — Dissolve 10 grams of iodine tri- 
chloride in I liter of pure glacial acetic acid, and finally add and dissolve 
10.8 grams of pure iodine. 

Other Reagents, as in the Hiibl and Hanus methods. 

Method of Procedure. — Proceed as in the Hanus method, observing the 
same precautions, the only difference being in the use of the Wijs iodine 
reagent. 

Wijs recommends the following periods of time for absorption of 
the iodine in the case of various oils: For non-dr}-ing oils and fats, such 
as peanut and olive oil,{ fifteen minutes; for semi-dr}'ing oils, such as 
cottonseed, rape, sesame, com, and mustard, thirty minutes; for dr}'ing 
oils, such as sunflower and poppyseed, one hour. 

The Bromine Index or Bromine Absorption Number. — The measure 
of the amount of bromine absorbed by the oils and fats is a useful factor. 
By the bromine index is understood the weight of bromine which is 



* Ber. d. chem. Ges., 31 (1898), p. 750. 

t The chlorine is conveniently prepared by treatment of bleaching powder with dilute 
sulphuric acid, using gentle heat, and washing the gas by passing through strong sulphuric 
acid. 

X For butter, oleo oil, lard oil, and cocoanut oil, fifteen minutes is sufficient. 



EDIBLE OILS A\'D FATS. 



493 



absorbed by i gram of a given oil. The bromine index of various oils 
has been determined as follows : 



Brorrir-e Index. 



Obser-.-er. 



Poppyseed, 
Mustard. . . 
Sesame. . . . 
Cottonseed 

Rape 

Peanut. . . . 
Olive 



0-835 




Levallois 


0.763 




Girard 


0.695 




Levallois 


0.645 




" 


0.632 




Girard 


0-530 




Levallois 


.500 to 0. 


544 


" 



Method of Levallois. — Five grams of the oil are saponified with alcoholic 
potash in a 50-cc. graduated flask by the aid of a gentle heat. At the end 
of the saponification and after cooling, the flask is filled to the mark -^ith 
alcohol, and, after shaking, 5 cc. are removed by means of a pipette and 
transferred to a flask. A slight excess of hydrochloric acid is added 
to set free the fatty acids, and from a burette a standardized solution 
of bromine water is run in till with constant shaking a permanent vellow 
color persists. The bromine is previously standardized with potassium 
iodide and sodiimi thiosulphate. The weight of bromine fixed by i gram 
of the fat is then calculated. 

Mills Method. — Modified.^ — Dissolve o.i gram of the filtered and 
dried fat in 50 cc. of carbon tetrachloride or chloroform in a loo-cc. stop- 
pered bottle. From a burette a standard solution of bromine in carbon 
tetrachloride, approximately tenth-normal (8 grams to a liter), is slowly 
added to the oil solution till, after fifteen minutes, a permanent coloration 
remains. The amount of bromine absorbed is calculated by comparing 
with the color similarly produced in a blank experiment, or an excess 
of bromine solution may be run in and the solution titrated back with a 
standard solution of thiosulphate, using potassium iodide and starch. 

Thermal Tests. — The rise in temperature produced by the aaion 
of certain reagents on various oils and fats, when apphed in a defi- 
nite manner, has been found to be of considerable value, especially in th© 
case of sulphuric acid and of bromine. 



* Villiers et Collin, Les Substances Alimentaires, p, 680. 
t Allen, Commercial Org. .Analysis, 11, part i, p. 63. 



494 FOOD INSPECTION AND ANALYSIS. 

The Maumene Test,* or thermal reaction with sulphuric acid, is most 
readily carried out in a beaker of say 150 cc. capacity, which is set into a 
larger beaker or vessel of any kind, the space between the two being packed 
with felt or cotton waste. The inner beaker is removed, and into it is 
weighed 50 grams of the oil. It is then replaced and the packing adjusted, 
if necessary, after which the temperature of the oil is noted with a ther- 
mometer. From a burette containing the strongest sulphuric acid of 
the same temperature as the oil, 10 cc. are run into the beaker, at the 
same time stirring the mixture of acid and oil with the thermometer. 
The temperature rises somewhat rapidly, and remains for an appreciable 
time at its maximum point, which should be noted. The difference 
in degrees centigrade between the initial temperature of the oil and the 
maximum temperature of the mixture expresses the Maumene number. 

With certain oils, as cottonseed, considerable frothing ensues when 
concentrated acid is employed, making an accurate determination of the 
Maumene number somewhat difficult. In this case it is better to employ 
a somewhat weaker acid, and to express results in terms of what is called 
the "specific temperature reaction." This is the result obtained by 
dividing the rise of temperature in the case of the oil by the rise of 
temperature in the case of water, using the same strength of acid, and 
multiplying the quotient by 100. Indeed, it is of importance in all 
cases to compare results on oils with those obtained by carrying out 
the same test on water. 

Bromination Test. — ^This test depends upon the avidity with which 
the oils and fats absorb bromine, the rise in temperature caused by the 
reaction being measured in this case rather than the actual amount of 
bromine absorbed, as in the case of the iodine absorption. Indeed, there 
is such a close relation between the iodine number and the heat of 
bromination, that when one is determined the other may be calculated 
quite closely by multiplying by a factor. In view of the fact that the 
heat of bromination is much more readily determined than the iodine 
number, it is often convenient to calculate the latter from the former, 
the result in the case of the edible oils and fats being quite sure to fall 
within the limits of variation of the iodine number of different oils of the 
same class. The bromination test was devised by Hehner and Mitchell,! 
who employed a vacuum jacketed tube for a calorimeter in which to 
make the test. Various modifications have been suggested both in the 



* Maumene, Compt. Rend., XXXV (1852), p. 572. 
t Analyst, XX (1895), p. 146. 



EDIBLE OILS AND FATS. 



495 



apparatus employed and in the manner of diluting the oil and 
applying the reagent. The calorimeter employed by Gill and Hatch,* 
Fig. 96, is conveniently made and is ver\' satisfactory. It consists of a 
long, narrow, flat-bottomed tube, held by a cork in a small beaker, in 
such a manner that it is surrounded by an air jacket. The small beaker 
is set into one of larger size, the space between the two being packed ^^^th 
cotton waste. Five grams of the oil or fat are dissolved in 25 cc. 





A. B. 

Fig. 96. 
A. Gill and Hatch's Calorimeter for the Bromination Test with Oils, 
B. Wiley's Pipette for Measuring Bromine in Chloroform. 

of chloroform or carbon tetrachloride, and 5 cc. of this solution 
(containing i gram of the oil) are transferred by a pipette to the 
inner tube of the above calorimeter, being careful not to let it flow 
down the sides of the tube. The temperature of the oil is then taken 
by a thermometer graduated to 0.2°. The bromine reagent, which 
should be freshly prepared, is made up by measuring from a burette 
one part by volume of bromine into four parts of chloroform or carbon 
tetrachloride. The reagent is transferred to a measuring-flask de^^sed 
by Wiley,t consisting of a side-necked filter- flask provided with a per- 

* Jour. Am. Chem. Soc, XXI (1899), p. 27. Gill, Oil Analysis, p. 50. 
t Jour. Am. Chem. Soc., XWUl (1896), p. 378. 



496 



FOOD INSPECTION AND ANALYSIS. 



forated rubber stopper into which the stem of a 5-cc. pipette is fitted, 
Fig. 96. A bulb on the side-neck serves to fill the pipette. This pipette, 
iilled to the mark with the bromine reagent (which should be at the same 
temperature as the oil solution in the calorimeter), is first covered bv the 
finger and removed, and its contents of 5 cc. allowed to flow down the 
sides of the inner tube of the calorimeter and mingle with the oil without 
stirring. The rise in temperature is very quick, and the highest point 
is noted. The difference between the highest and the initial temperature 
constitutes the heat-of-bromination number. 

This number, in the case of Gill and Hatch's calorimeter, is somewhat 
lower than when a vacuum jacketed tube is employed, and differs some- 
what with the diluent of the oil and bromine. In spite of these variations 
and that due to the personal equation, concordant results may be obtained 
with the vaiious oils, when the method is carried out under precisely the 
same conditions. The analyst should carefully work out the test several 
times with a particular oil till the results agree, and should then with 
equal care determine the iodine number of the same oil. The iodine 
number, divided by the heat-of-bromination number, gives the factor 
which is to be employed under the same conditions for calculating one 
constant from the other. In the case of Hehner and Mitchell's work 
with the vacuum tube, measuring i cc. of undiluted bromine into i gram 
of oil dissolved in 10 cc. of chloroform, it was found that the factor to 
be used in calculating the iodine number was 5.5. 

The following are some of the results on edible oils obtained by Hehner 
and Mitchell: 



Oil. 


Heat of 
Broniination. 


Iodine 
Number. 


Calculated 
Iodine Number. 




10.6 

6.6 
15 

21-5 

19.4 


57-15 
37-07 
80.76 

122 

107.13 


58.3 
36.3 

82.5 
118 2 


Butter 

Olive oil 

Corn oil 


•'Cottonseed oil 


106.7 





As in the case of the Maumene test with sulphuric acid (wherein 
the rise in temperature of sulphuric acid and water is taken as a standard), 
it is convenient to employ some standard for the bromination test, whereby 
var)dng results due to difference in apparatus, etc., may be compared. 

In this case Gill and Hatch found that sublimed camphor may be. 
prepared sufficiently pure to be used for such a standard. Applying the 
bromination test with their calorimeter, as above described, to 5 cc. of a 



EDIBLE OILS /IND FATS. 



497 



solution of 7 J grams of camphor in 25 cc. of carbon tetrachloride, an average 
rise in temperature of 4.2° was obtained, and the specific temperature 
reaction is calculated for each oil by dividing the heat of bromination 
by this number. Furthermore, by dividing the iodine number of several 
oils by this specific temperature reaction, the factor to be employed for 
the calculation of the iodine number was found to be 17.18, as in the fol- 
lowing cases : * 



Oil. 



Specific Tem- 
perature 
Reaction. 



Iodine Number. 



Calculated. 



Found. 



Prime lard 
No. I lard. 

Olive 

Cottonseed 
Com 



3-705 
4.096 
4.762 
5.667 
6.^81 



63 

70 
81 

97 
109 



63.8 

73-9 

82.0 

103.0 

107.8 



The Acetyl Value. — On heating fats with acetic anhydride they 
become "acetylated" ; i.e., the hydrogen atom of their alcoholic hydroxyl 
group is exchanged for the acetic acid radicle, in accordance, for example, 
with the following reaction: 

CnH3,(OH)COOH+(C2H30)20 = CnH32(0,C,H30)COOH+C2H,03- 

Ricinoleic Acetic anhy- Acetyl-ricinoleic Acetic 

acid dride acid acid 

By the actyl value is meant the number of milligrams of potassium 
hydroxide necessary to neutralize the acetic acid formed by the saponifi- 
cation of I gram of the acetylated fat. 

Lewkowitsch's method of procedure is as follows: 10 grams of the 
oil are boiled with an equal volume of acetic anhydride for two hours 
in a flask with a return-flow condenser, and the mixture is then trans- 
ferred to a large beaker containing 500 cc. of water, and boiled for half 
an hour. To prevent bumping, a current of carbon dioxide is slowly 
passed through it during the boiling, introduced through a finely drawn, 
bent glass tube reaching nearly to the bottom of the beaker. The mix- 
ture on standing separates into two layers, of which the lower, or aqueous 
layer, is siphoned off, and the oily layer boiled with fresh portions of 



* Gill, Oil Analysis, p. 128. 



498 FOOD INSPECTION AND ANALYSIS. 

water, which are in turn siphoned off, the operation being repeated till 
the wash water tests free from acid by litmus paper. 

The acetylated fat is then separated from the water by drv'ing at 
100° in an oven. 

From 2 to 4 grams of the acetylated fat is weighed into a flask, and 
saponified with alcoholic potash in precisely the same manner as for 
the determination of the saponification number. Evaporate the alcohol 
and dissolve the soap in water. One of two methods may be carried 
out for freeing the acetic acid for titration, one by distillation and the 
other by filtration. 

For the former or distillation process, acidify the aqueous solution 
of the soap with i : 10 sulphuric acid, and distill in the same way as in the 
Reichert process, excepting that in this case from 600 to 700 cc. of dis- 
tillate must be obtained, so that water should be added from time to 
time through a stoppered funnel fixed in the cork of the distilling-flask. 
The distillate should be received in a funnel with a loose cotton plug, so 
as to filter it free from insoluble acids mechanically carried over. The 
filtrate is titrated with tenth-normal sodium hydroxide, using phenol- 
phthalein as an indicator. The number of cubic centimeters of alkali 
used is multiplied by 5.61, and the product divided by the number of 
grams of acetylated fat taken. The result is the acetyl value. 

If the filtration process is used (which is more rapid and should give 
concordant results with the distillation process), the exact amount of 
alcoholic potash used in the saponification should be accurately measured 
in carrying out the former part of the test, and the exact number of cubic 
centimeters of standard acid corresponding to the amount of alkali 
employed should be added to the aqueous soap solution. The mixture 
should be gently warmed, and the fatty acids will gather in a layer at the 
top. These are filtered oft" and washed, till free from acid, with boiling 
water. The filtrate is titrated with tenth-normal sodium hydroxide, and 
the acetyl value calculated as in the distillation process. 

EDIBLE OILS ARRANGED IN ORDER OF ACETYL VALUE. 

Average. 

Cottonseed oil 18.0 

Rape oil 14. 7 

Poppysecd oil 13 . i 

Sesame oil 1 1 - 5 

Olive oil 10.6 

Peanut oil 3.4 



EDIBLE OILS A\D FATS. 



499 



The Valenta Test. — This depends upon the solubility of the oil in 
glacial acetic acid. Pour from 3 to 5 cc. of the oil into a test-tube, and 
add an equal volume of glacial acetic acid (specific gra\ity 1.0562). 
Place a thermometer in the tube and warm gently till the oil goes into 
solution. Then allow the mixture to cool, and observe the temperature 
at which the solution begins to appear turbid. 

Castor oil and oil of the olive kernel are soluble in glacial acetic acid 
at ordinar}- temperatures, while rape and mustard seed oils are insoluble 
even in the boiling acid. 

Elaidin Test. — This is based on the conversion by nitrous oxide of 
liquid olein into the sohd elaidin, a cr\-stalline compoimd isomeric xA-ith 
olein, while other common glyce rides remain liquid under treatment 
with this reagent. By the consistency of the final product, when sub- 
jected under certain conditions to the action of nitrous oxide, some idea 
as to the character of the oil may be gained. 

Manipulation. — To cany^ out the test according to Pontet (modified), 
weigh 5 grams of the oil into a beaker, add 7 grams of nitric acid (specific 
gravity 1.34) and about 0.5 gram of copper wire. Place the beaker in 
water at 15° and stir thoroughly -^^th a glass rod in such a manner as 
to make an intimate mixture of the oil and the evolved nitrous oxide gas. 
After the wire has been dissolved, add another piece of about the same 
size and again stir \'igorously. Set aside for about two hours, at the end 
of which, in the case of pure olive, almond, peanut, or lard oil, it ^^■ill 
have been changed into a sohd white mass. 

Nearly all the seed oils, especially cottonseed and mustard, are turned 
into a pasty or butter}' mass. 

Another modification of Pontet's test consists in mixing 10 grams 
of the oil, 5 grams of nitric acid (specific gra\'ity 1.38), and i gram of 
mercur}" in a test-tube, shaking for three minutes and allowing to stand 
twenty minutes, when it is again shaken. 

The behavior of various oils after that time on further standing is as 
follows : 

Solidified after 

Olive oil 60 minutes 

Peanut oil '. 80 " 

Sesame oil 185 " 

Rape oil 185 " 

Free Fatty Acids,* — Weigh 20 grams of the oil or fat into a 150-cc 
Erknmeyer fiask, and add 50 cc. of 95*^^ alcohol, which has pre\'iously 
* Allen Com. Org, Anal, 3d ed., vol, 2, pt. i, p, 105. 



500 FOOD INSPECTION AND ANALYSIS. 

been carefully neutralized with a weak solution of sodium hydroxide, 
using phenolphthalein as an indicator. Warm the mixture to about 60°, 
and add carefully from a burette tenth-normal sodium hydroxide (using 
the above indicator) till a pink color is produced, shaking thoroughly 
during the titration. 

The result may be reported in terms of percentage of oleic acid (each 
cubic centimeter of tenth-normal alkali is equivalent to 0.0282 gram of 
oleic acid) or as the "acid number," by which is meant the number of 
cubic centimeters of tenth-normal alkali necessary to saturate the free 
acid in i gram of the fat or oil. 

Constants of the Free Fatty Acids. — Often much information as to 
the character of an oil or fat may be obtained by determining such con- 
stants of its fatty acids as the melting- and solidifying-point, the iodine 
number, etc. 

To prepare the fatty acids for examination, saponify a quantity of the 
oil or fat with alcoholic potash, evaporate the alcohol, and dissolve the 
soap in hot water. Decompose the soap by the addition of an excess 
of hydrochloric or sulphuric acid, continuing the heating till the fatty 
acids rise in a layer to the top of the liquid, from which they may be 
removed. The melting-point, iodine number, etc., are determined as 
with tlie oil or fat itself. 

Solidifying-point of the Fatty Acids, or Titer Test. — Modified 
Wolfbauer Method.'^ — Saponify 75 grams of fat in a metal dish with 60 cc. 
of 30% sodium hydroxide (36° Baume) and 75 cc. of 95% by volume 
alcohol or 120 cc. of water. Boil to dryness, with constant stirring to 
prevent scorching, over a very low flame, or over an iron or asbestos plate. 
Dissolve the dry soap in a liter of boiling water, and if alcohol has been 
used, boil for forty minutes in order to remove it, adding sufficient water 
to replace that lost in boiling. Add 100 cc. of 30% sulphuric acid (25° 
Baume) to free the fatty acids, and boil until they form a clear, trans- 
parent layer. Wash with boiling water until free from sulphuric acid, 
collect in a small beaker, and place on the steam bath until the water has 
settled and the fatty acids are clear; then decant them into a dry beaker, 
filter, using a hot-water funnel, and dry twenty minutes at 100° C. 

When dried, cool the fatty acids to 15 or 20° C. above the expected 
titer, and transfer to the titer tube, which is 25 mm. in diameter and 100 
mm. in length (i by 4 inches), and made of glass about i mm. in thickness. 
Place in a i6-ounce saltmouth bottle of clear glass, about 70 mm. in 
diameter and 150 mm. high (2.8 by 6 inches), fitted with a cork, which is 
perforated so as to hold the tube rigidly when in position. Suspend the 

* A. O. A. C. Method, U. S. Dept. of Agric, Bur. of Chem.. Bui. 107, p. 135. 



EDIBLE OILS AND FATS. 501 

thermometer, graduated to 0,10° C, so that it can be used as a stirrer, 
and stir the mass slowly until the mercury remains stationary for thirty 
seconds. Then allow the thermometer to hang quietly, with the bulb in 
the center of the mass, and observe the rise of the mercury. The highest 
point to which it rises is recorded as the titer of the fatty acids. 

Test the fatty acids for complete saponification as follows: 

Place 3 cc. in a test tube and add 15 cc. of alcohol (95% by volume). 
Bring the mixture to a boil and add an equal volume of ammonium 
hydroxide (0.96 sp. gr.). A clear solution should result, turbidity indicat- 
ing unsaponified fat. The titer must be made at about 20° C. for all 
fats having a titer above 30° C. and at 10° C. below the titer for all other 
fats. 

The thermometer must be graduated in tenth degrees from 10° to 60°, 
with a zero mark, and have an auxiliary reservoir at the upper end, also 
one between the zero mark and the 10° mark. The cavity in the capillary 
tube between the zero mark and the 10° mark must be at least i cm. below 
the 10° mark, the 10° mark to be about 3 or 4 cm. above the bulb, the 
length of the thermometer being about 15 inches over all. The thej- 
mcmetcr is annealed for 75 hours at 450° C, and the bulb is of Jena 
normal 16'" glass, moderately thin, so that the thermometer will be 
quick acting. The bulb is about 3 cm. long and 6 mm. in diameter. 
The stem of the thermometer is 6 mm. in diameter and made of the best 
thermometer tubing, with scale etched on the stem, the graduation to be 
clear cut and distinct, but quite fine.* 

Unsaponifiable Matter. — As will be seen by reference to the table 
on page 509, the unsaponifiable matter in pure edible oils and fats is 
comparatively insignificant in amount, consisting largely of cholesterol or 
phytosterol. A high content of unsaponifiable matter is indicative of 
adulteration, pointing to the presence of mineral or coal-tar oils, or to 
paraffin. 

Determination of Unsaponifiable Matter.f — Weigh 7 to 10 grams of 
the fat or oil in a 250-cc. flask, and saponify by boihng with 25 cc. of 
alcoholic potassium hydroxide and 25 cc. of alcohol under a return- 
flow condenser. After saponification, add 30 to 40 cc. of water, and 
bring to the boihng-point. Cool and transfer the contents from the 
flask to a separatory funnel, washing out the flask first with a small amount 



* Tolman, U. S. Dept. of Agric, Bur. of Chem., Bui. 90, p. 75. 
t Honig and Spitz, Jour. Soc. Chem. Ind., 1891, p. 1039. 



502 FOOD INSPECTION AND ANALYSIS. 

of 50% alcohol, and finally with 50 cc. of petroleum ether (B.P. 40°-7o°), 
adding both washings to the separatory funnel. Shake the latter 
thoroughly, but avoid if possible forming an emulsion. If the latter 
persists in forming, add a volume of water equal to that of the soap solu- 
tion, w^hich will sometimes break it up. After separation of the petro- 
leum ether layer, draw off the underlying soap solution into a beaker, 
and wash the petroleum ether two or three times with 50% alcohol, which 
is drawn off and added to the soap solution. The petroleum ether is 
then run into a tared Erlenmeyer flask, and the soap solution extracted 
twice more with fresh portions of petroleum ether, washing the ether 
each time with 50% alcohol as before and then transferring the ether 
to the tared flask. The petroleum ether is then removed by placing 
the flask on the water-bath, bumping being prevented by means of a 
spiral of platinum wire weighed with the flask. Finalh' remove all traces 
of remaining ether by blowing hot air through the flask, or, in the absence 
of mineral oils (some of which arc volatile), dry in the water-oven to con- 
stant weight, cool in a desiccator, and weigh. 

Cholesterol and Phytosterol. — These are monatomic alcohols, and 
combine with the fatty acids forming esters. Both respond to the same 
reactions, ^nd are separated by the same process from the oils and fats 
in which they occur. Phytosterol was long thought to be the same as 
cholesterol, and some confusion seems to have arisen from the fact that 
early writers purport to have found cholesterol in vegetable oils, when 
in reality the substance was phytosterol. The latter was first distinguished 
from cholesterol by Hesse, who named it. 

Cholesterol (C26H44O) crystallizes in white, nacreous, monoclinic 
laminae, having a mehing-point of 145° and specific gravity 1.067. ^^^ 
reaction is neutral, it is devoid of taste or smell, insoluble in water, sparingly 
soluble in cold, but readily soluble in boiling alcohol, and soluble in ether, 
chloroform, methyl alcohol, benzene, and oil of turpentine. It sublimes 
unchanged at 200°, but at higher temperatures decomposes. 

Commercial cholesterol is obtained from wool oil and is known as 
lanolin, being used largely in medicine as a basis for ointment. 

Cholesterol occurs also in the yolk of eggs, in many animal secretions, 
and in most animal oils and fats. 

It separates in laminated, transparent crystals from a mixture of 
2 volumes alcohol and i volume ether, and in the form of anhydrous 
needles from chloroform. 

Phytosterol (C,6H^p,H,0) is most abundantly found in the legu- 



EDIBLE OILS AND FATS. 503 

minous seeds, and is prepared commercially from these, especially from 
peas and lentils. It is a constituent of most vegetable oils. 

It crystallizes in slender, glittering plates from chloroform, ether, 
and petroleum ether, and from alcohol in tufts of needles. In solubility it 
much resembles cholesterol, but its melting-point from 132° to 134° is lower. 

Determination of Cholesterol and Phytosterol. — Method of For ster and 
Reiclujiatni.* — ^o grams of the oil or fat are boiled for five minutes in 
a flask connected with a reflux condenser with two successive portions 
of 75 cc. of 95% alcohol, and in each case the alcoholic solution is sepa- 
rated by means of a separatory funnel. The combined alcoholic solutions 
are then boiled in a flask provided with a funnel in the neck, till one- 
fourth of the alcohol is evaporated, and then poured into an evaporating 
dish and brought to dryness. The residue is then extracted with ether, 
and the ether solution is evaporated to dryness, taken up again with ether, 
filtered, evaporated once more, and dissolved in hot 95% alcohol, from 
which it is allowed to crystallize. Cholesterol or phytosterol will crys- 
tallize out under these conditions, and may be weighed. 

Distinguishing between Cholesterol and Phytosterol. — It is some- 
times of importance to determine which of these substances is present in 
an oil, or whether indeed both occur. Confirmatory proof as to the 
presence of vegetable in animal oils may, for instance, be established by 
showing whether the unsaponifiable residue in the sample contains choles- 
terol or phytosterol or both. Hehner f has made use of this test in deter- 
mining the presence of cottonseed oil in lard. 

The most ready means of distinguishing between cholesterol and 
phytosterol is furnished by the marked difference between the form of the 
crystals, the manner of crystallization of the two substances, and the 
melting points of the acetates. 

Separation and Crystallization of Cholesterol and Phytosterol. — 
Bbmefs Method.% — Saponify 100 grams of the fat by heating in a liter 
Erlenmeyer flask on a boiling water bath with 200 cc. of alcoholic potash 
solution (200 grams of potassium hydroxide -f- 1 liter of alcohol). The 
flask should be provided with a perforated rubber stopper, through which 
passes a glass tube 700 cm. long, which serves as a reflux condenser. 
During the first part of the heating shake often and vigorously until the 
solution is clear, after which continue the heating one-half to one hour 
longer with occasional shaking. 

* Analyst, 22, 1897, p. 131. 

t Ibid., 13, 1888, p. 165. 

X Zeits. Unters. Nahr. Genuss., i, 1898, p. 31. 



504 FOOD INSPECTION AND y)NALYSIS. 

While still warm, transfer to a separatory funnel of about 1.5 liters 
capacity, rinsing the flask with 400 cc. of water. When cool, add 500 cc. 
of ether, shake vigorously for one-half to one minute, opening the cock 
repeatedly, and allow to stand for two to three minutes until the liquids 
separate. Remove the ether solution to a flask, and distil off the ether, 
using a few pieces of pumice stone to prevent bumping. Shake the soap 
solution two to three more times in the same manner with 200 to 250 cc. 
of ether, add the ether solution after each shaking to the residue in the 
distilHng flask, and distil off the ether. 

Usually a small amount of alcohol remains in the flask after removal 
of the ether, which may be removed by heating on a boiling water bath 
in a blast of air. To saponify any remaining fat, add 20 cc.of the alcoholic 
potash solution, and heat for five to ten minutes as before. Transfer 
to a small separatory funnel, rinse with 40 cc. of water, cool and shake 
with 150-200 cc. of ether from one-half to one minute, allow to stand two 
to three minutes, and draw off the lower layer. Wash the ether solution 
three times with 10-20 cc. of water, filter, to remove drops of water, into 
a small beaker, and remove the ether by cautious evaporation on the 
water bath, thus obtaining the crude cholesterol or phytosterol. 

The unsaponifiabie residue, which may be weighed after drving, in 
the case of animal fats shows beautiful radiating crystals, and consists 
largely of cholesterol, while in the case of vegetable fats it consists largely 
of phytosterol. Dissolve the residue in 4-20 cc. of absolute alcohol with 
the aid of heat, and allow to crystallize slowly in a shallow dish. 

The crystallization in the case of cholesterol alone begins from the 
margin of the liquid and gradually extends inward toward the center, 
forming a uniformly bright, thin, colorless film over the whole surface. 
This film is best removed with a knife or spatula and pressed between 
filter-paper. The film will be seen, even megascopically, to be composed 
of large, glossy plates with a silk-like luster. After the removal of the 
first film a second will form similar to the first, but composed as a rule 
of smaller crystals. These are removed in like manner, dried between 
filters, and added to the first in a glass. After the second crop, the mother 
liquid is thrown away. The crystals are then redissolved in absolute 
alcohol, and again allowed to separate out, being repeatedly recrystallized 
till the melting-point is constant. In lard and most fats the crystals 
were found pure by B5mer after the second crystallization. 

Phytosterol is crystallized with greater difficulty, especially when 
derived from seed oils, on account of the presence of pigments and other 



EDIBLE OILS AND FATS. 



50s 



foreign matter. The first procedure is the same as above described for 
cholesterol, the crystals being allowed to separate slowly out of a solu- 
tion in absolute alcohol. Unlike cholesterol, no film is formed on the 
surface, but needles (sometimes i cm. in length) are gradually elim- 
inated, beginning at the margin and extending inward mostly at the 
bottom. In concentrated solutions, fine needles would be uniformly 
deposited through the liquid. These are best separated from the mother 
liquid by filtration, as they are not easily taken out with a knife. They 
may be washed on the filter with small amounts of absolute alcohol for 
microscopical examination, or repeatedly recrystallized, as in the case 
of cholesterol, till the melting-point is constant. 

I. Cholesterol Crystals. — When crystallized separately under above 
conditions, cholesterol crystals viewed under the microscope show generally 
rhomboidal forms of plates, as in Fig. 97, but sometimes with a reenter- 




Fig. 97. — Cholesterol Crystals under the Microscope. (After Bomer.) 



ing angle. The plates are often grown together in masses. The most 
characteristic forms are found from the first crystallization or from 
the first film removed. Sometimes quadrilateral crystals predominate 
among the plates, often also the other shapes shown are found most 
numerous. 

2. Phytosterol Crystals. — Pure phytosterol crystallizes in needles or 
narrow plates, arranged commonly in star form or in bunches. The 
most common forms are shown in Fig. 98, best conditions as to shape 
of crystals being obtained from slow crystallization, in which case the 
needles are finer and more regular. 

The crystals are commonly in the form of long, narrow plates, thin 
and slender, often pointed at both ends. Sometimes the points are 
lacking, or the ends are beveled. The more frequently they are re- 
crystallized, the larger and more varied are the crystal forms. The 
broad, hexagonal and quadrilateral plates showm are products of re- 



5o6 



FOOD INSPECTION AND ANALYSIS. 



crystallization; the shorter forms are rarely met with. Sometimes various 
forms are found side by side in the same crystallization. 

Phytosterol crystals, from a second oi* third recrystallization, some- 
times grow together in bunches resembling at fitst glance to the naked 
eye the cholesterol masses. They never do this in the first crystallization, 
whereas in the case of cholesterol the growing together in masses is very 
characteristic of the first crystallization. 




/ 



Fig. 98. — Phytosterol Crj-stals. (After Bomer.) 

Thus for purposes of distinguishing between the two the product 
of the first crystallization is best observod. 

3. Crystals of Mixed Cholesterol and Phytosterol. — In mixtures of the 
two they do not cr}^stallize separately, but when in nearly equal propor- 
tion, or with phytosterol predominating, the crystals much resemble 
phytosterol. Even when cholesterol predominates to the extent of 20 
parts to I of phytosterol, the mode of crystallization leans most toward 
that of phytosterol, though the needles are of different shape. Such a 
mixture, for instance, does not form in a film like cholesterol, but, like 
phytosterol, comes out in needle-like bunches. The needles, however, 
are more often like those shown in Fig. 99 when viewed under the micro- 




NlHiJ 




fiG. 99.— Characteristic Forms of Crystallization of Mixed Cholesterol and Phytosterol 

(After Bomer.) 

scope, showing needles for the most part squarely cut off at the ends, 
and sometimes placed end to end, and of varying diameter, giving the 
appearance of a spy-glass. When cholesterol predominates over phy- 
tosterol 50 to I, the plates resemble those of cholesterol. 



EDIBLE OILS /iND FATS, 507 

Bomer's Phytosterol Acetate Test for Vegetable Fats.* — Dissolve 
the crude cholesterol or phytosterol, or the mixture of the two, obtained 
by Bomer's method, as described on page 503, in the smallest possible 
amount of absolute alcohol, and allow to crystallize. Examine under 
the microscope the first crystals that separate, comparing with the cuts 
and descriptions given in the preceding section. Remove the alcohol 
completely by evaporation on the water bath, add 2 to 3 cc. of acetic 
anhydride, cover with a watch glass, and boil for one-fourth minute on a 
wire gauze; then remo^•e the watch glass, and evaporate the excess of 
acetic anhydride on the water bath. Heat the residue with sufficient 
absolute alcohol to dissolve the esters, and add enough more to prevent 
immediate crystallization on cooling. Cover until the room temperature 
is reached and allow to crystallize. 

x^fter one-half to one-third of the liquid has evaporated and the greater 
part of the esters have crystallized, transfer the crystals to a small filter 
by the aid of a small spatula, rinsing with two portions of 2 to 3 cc. of 
95% alcohol. Return the crystals to the crystallizing dish, dissolve in 
5 to 10 cc. of absolute alcohol, and again allow to crystallize. After the 
greater part of the crystals have separated, collect on a filter as before. 
Repeat the recrystallization several times (5 to 6 is usually sufficient), 
determining the melting point of the crystals after each recrystallization 
beginning with the third. 

If after the last crystalhzation the corrected melting point of the 
crystals is above 116°, the presence of a vegetable fat or oil is indicated, if 
it is 117° or higher the proof may be regarded positive. 

The standard thermometer used should be graduated to tenths of a 
degree. Correct the reading by the following formula: 

S = T ^ o.oooi ^4n{T —t) 
in which 5=-- the corrected melting point, 2" = the observed melting point, 
w = the length of the mercury column above the surface of the liquid, 
expressed in degrees, and / = the temperature of the air about the mercury 
column as determined by a second thermometer, 

Bomer states that by this method the analyst can detect in edible 
animal fats i to 2 per cent of oils rich in phytosterol (cottonseed, peanut, 
sesame, rape, hemp, poppy, and linseed), and 3 to 5 per cent of oils con- 
taining smaller amounts of this constituent (olive, palm, palm kernel, 
and probably cocoanut). He found the corrected melting point of choles- 
terol acetate to be 114.3° ^^ 114.8° and of phytosterol acetate, 125.6° to 
137.0° according to the source. 

* Zeits. Unters. Nahr. Cienuss., 4.. 1901, p. 1070. 



5o8 



FOOD INSPECTION AND ANALYSIS. 



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EDIBLE OILS AND FATS. 



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5IO FOOD INSPECTION .-IND .4N.-1I.YSIS. 

Numerous experiments, made both in Europe and America, show that 
feeding milch cows and swine with oil cakes does not introduce phytos- 
terol into either the fat of the milk or the lard, although both fats may 
respond to the Halphen test, or give abnormally high Polcnske numbers 
as a result of feeding with cottonseed or cocoanut cake respectively, and 
although the lard (not the butter fat) may respond to the Baudouin test, 
owing to feeding with sesame cake. (See pp. 531, 560). 

Paraffin, sometimes present as an adulterant of fats, is best deter- 
mined as follows:* Boil 2 grams of the fat with 10 cc. of 95% alcohol 
and 2 cc. of I : I sodium hydroxide solution, connect the flask with a retlux 
condenser, and heat for an hour on the water-bath, or until saponification 
is complete. Remove the condenser, and allow the flask to remain on 
the bath till the alcohol is evaporated off and a dry residue is left. Treat 
the residue with about 40 cc. of water and heat on the bath, with frequent 
shaking, till everything soluble is in solution. Wash into a separatory 
funnel, cool, and extract with four successive portions of petroleum ether, 
which are collected in a tared flask or capsule. Remove the petroleum 
ether by evaporation and dry in the oven to constant weight. 

It should be noted that any phytosterol or cholesterol present in the 
fat would come down with the paraffin, but the amount would be so insig- 
nificant that with added paraffin actually present, it may be disregarded. 
The character of the final residue should, however, be confirmed by 
determining its melting-point and specific gravity, and by subjecting 
it to examination in the butyro-refractometer. The melting-point of 
paraffin is about 54.5° C; its specific gravity at 15.5° is from 0.868 to 
0.915, and on the butyro-refractometer the reading at 65° C. is from 
II to 14.5. 

MICROSCOPICAL EXAMINATION OF OILS AND FATS. 

Excepting in the case of solid fats, the use of the microscope has 
hitherto been comparatively restricted. In the examination of lard and 
butter for adulterants, the use of the microscope is often of great value, 
and will be described more fully under these special fats. In general 
the best fat crystals are obtained by slow crystallization at room tempera- 
ture from an ether solution, or from a mixture of ether and alcohol. The 
first crystals formed may often with advantage be filtered out, and washed 
with the alcohol and ether mixture on the filter, dissolved finally in ether, 
and the latter allowed to evaporate spontaneously. The crystals are 
then examined in a medium of ether. 

t U. S. Depl. of Agric, Div. of Cheni., Bui. O5, p. 46. 



EDIBLE OILS AND FATS. 511 

If it be desired to separate the liquid olcins from an oil, so that crystals 
of the solid fats are left for examination, Gladding* recommends dis- 
solving the fat in a mixture of two volumes of absolute alcohol and one 
volume of ether in a test-tube, which is stoppered with cotton and set 
for half an hour in ice water, during which time the more solid stearin 
and palmitin will have crystallized out. This portion is then separated 
from the mother liquor by filtration through an alcohol- wet filter- paper, 
and the crystals finally treated as in the preceding section, being examined 
in a medium of olive or cottonseed oil. 



OLIVE OIL. 

Source. — Olive oil is derived from the fruit of the cultivated thorn- 
less olive tree, Oka Europaa sativa,^ of which there are a great many 
varieties, originally grown in Asia Minor, Greece, Palestine, and southern 
Europe, and now cultivated extensively in California, Peru, and Mexico, 
as well as in Australia. Most of the olive oil of commerce, especially 
of the choicest varieties, is supplied by southern France, Spain, and Italy. 
The tree is an evergreen of slow growth and great longevity. 

The ripe olive fruit is purple or purplish black in color; it is round or 
oval in shape, and from 2.5 to 4 cm. in diameter. The oil is contained in 
the parenchyma cells of the fruit suspended in a watery fluid. A thick 
skin incloses the fruit, and within is a kernel, which itself contains oil. 
The fruit contains from 40 to 60 per cent of oil. According to Brannt,{ 
the average composition of the olive is as follows: 





Flesh, 
Per Cent. 


Stone, 
Per Cent. 


Seed, 
Per Cent. 


Oil 


56-4 
16.70 

I.IO 

2.68 
24.22 


5.75 
85.89 

2.50 
4.16 
4.20 

100.00 


12.26 




79-38 

2 . 16 


Nitrogen therein 


Ash 


2.16 


Water 


6 20 








100.00 


100.00 



Preparation. — The finest virgin oil is produced from hand-picked, 
peeled olives, from which the kernels or pits have been removed. A 
somewhat inferior grade of oil is produced from the whole olive including 
the pit, while a distinctly low grade oil is obtained from the stones, or 
kernels, which are ground into a coarse meal and subjected to pressure, or 
to the action of such solvents as carbon bisulphide. 

* Jour. Am. Chem. See. 1896, 18, p. 189. 

t As distinguished for the wild thorny species, Europaa sylvestris. 

X Animal abd Vegetable Fats and Oils. 



512 FOOD INSPECTION AND ANALYSIS. 

In the process of manufacture the fruit, after first being dried, is re- 
duced to a pulp in a stone or iron mill, and the pulpy mass, contained in 
baskets or bags, is subjected to pressure in an iron press. The very highest 
grade of virgin oil is that which runs out from the pulp with little or no 
pressure. After the first pressing, the pomace is ground, treated with 
water, and again subjected to pressure. Several pressings in this manner 
may be carried out, each yielding an oil inferior to that preceding, the 
lowest grades being used for lubricants and in the manufacture of soap. 

Nature and Composition. — The better grades of olive oil, suitable for 
table and medicinal purposes, possess a pleasant, bland taste, and a 
distinctive and agreeable odor, unmistakable in character for that of any 
other oil. The finest virgin oil is pale green in color, due to the presence 
of chlorophyll, which is closely associated with the oil globules in the 
cellular tissue of the fruit. Some varieties of olive oil are nearly color- 
less, while others are a deep golden yellow. 

Olive oil contains 28% of solid glycerides, chiefly palmitin and a very 
small amount of arachin, and 72% of liquid glycerides, mainly olein with 
a little linolein. Stearin is practically absent. 

Lewkowitch* states that olive oil differs from most vegetable oils in 
containing cholesterol but not phytosterol. 

Gill and Tufts f show, as a result of numerous experiments, that olive 
oil is not thus exceptional, but that the unsaponifiable alcohol is phytos- 
terol and not cholesterol. 

Olive oil is very soluble in chloroform, benzol, and carbon bisulphide, 
but is sparingly soluble in alcohol. Five parts of ether will dissolve 
3 parts of the oil. 

Adulterants. — As a rule the low grade oHve oils are most subject 
to adulteration, by reason of the fact that it hardly pays to destroy or even 
modify the fine quality and delicacy possessed by a first-class oil, which 
would inevitably be the result if even a small amount of foreign oil were 
added. Furthermore, if olive oil be slightly rancid or for any reason lacking 
in flavor, the admixture of a bland oil tends rather to minimize the fact. 

The most common adulterant of olive oil in this country is naturally 
cottonseed oil, which is often substituted wholly for it. In Europe 
peanut oil is sometimes used both as an admixture and even as a substi- 
tute, since it possesses in itself a rather pleasant flavor, rendering it 
especially adapted for use as an adulterant. Other cheap oils used for 
this purpose are corn, mustard, poppyseed, rape, sesame, and sunflower 

* Chem. Anal, of Oils, Fats, and Waxes, 2d ed.., p. 452. 
t Jour. Am. Chem. Soc, XXV, 1903, p. 498. 



EDIBLE OILS AND FATS. 



513 



oil. The writer has also found in samples of alleged olive oil sold in 
Massachusetts cocoanut oil* and even fish oil. 

Pure Olive Oil of the U. S. Pharmacopoeia. — The requirements of 
the Pharmacopoeia are as follows: 

Specific gravity, 0.910 to 0.915 at 25° C. (77° F.) ; iodine value not 
less than 80 nor more than 88; saponification value 191 to 195. Very 
sparingly soluble in alcohol, but readily soluble in ether, chloroform, or 
carbon disulphidc. 

When cooled to about 10° C. (50° F.), the oil should become some- 
what cloudy from the separation of crystalline particles, and at 0° C. 
(32° F.) it should form a whitish, granular mass. 

If 2 cc. of olive oil be shaken vigorously with an equal volume of 
nitric acid (sp. gr. 1.37), the oil should retain a light yellow color, not 
becoming orange or reddish brown, and after standing for six hours, should 
change into a yellowish-white solid mass and an almost colorless liquid 
(absence of appreciable quantities of cottonseed oil and other seed oils). 
Olive oil should not show the cottonseed oil reaction with the Bechi and 
Halphen test, p. 5 18, nor the sesame oil reaction with the Baudouin test, p. 519. 
U. S. Standards, — Olive oil is the oil obtained from the sound, mature 
fruit of the cultivated olive tree {Oka europoea L.) and subjected to the 
usual refining processes; is free from rancidity; has a refractive index 
(25° C.) not less than 1.4660 and not exceeding 1.4680; and an iodine 
number not less than 79 and not exceeding 90. Virgin olive oil is olive 
oil obtained from the first pressing of carefully selected, hand-picked olives 
Reaction with Strong Acid. — ^Pure ohve oil, when shaken or stirred 
with an equal volume of concentrated nitric or sulphuric acid, turns from 
a pale to a dark-green color in a few minutes. If, under this treatment, 
a reddish to an orange, or brown coloration is produced, the presence 
of a foreign vegetable oil (usually a seed oil) is to be suspected. 

Bach gives the following table showing the action of strong nitric acid 
on various oils: 



Kind of Oil. 


After Agitation 
with Nitric Acid. 


After Heating for 
Five Minutes. 


Consistency after 

Standing Twelve to 

Eighteen Hours. 


Olive 


Pale green 
' ' rose 

White 
Dirty white 
Yellowish brown 
Pale rose 


Orange-yellow 
Brownish yellow 
Orange-yellow 
Brownish yellow 
Reddish yellow 
Reddish brown 
Golden vellow 


Solid 


Peanut 

Rayje 

Sesame 


Liquid 

Buttery 
( < 

it 


Sunflower 

Cottonseed 

Castor 



* A sample of alleged oli\e oil purchased in a Massac'iusetts drug store and found to 
be adulterated with cocoanut oil, had the following constants: 

Specific gravity 0.91 1 Iodine number 74.5 

Reichert-Meissl number 2.90 Butro-refractometer at 26° 56.5 



514 



FOOD INSPECTION /iND /IN /4 LYSIS. 



The Zeiss Butyro-refractometer furnishes one of the most useful 
and easily applied preHminary means of judging the purity of the sample. 
If the reading is beyond the limits of pure olive oil, it at once indicates 
adulteration and often points to the particular adulterant. On the other 
hand, it is not always safe to assume the oil to be pure if the reading is 
correct, since mixtures of higher and lower refracting foreign oils may 
be so skillfully prepared as to read well within the limits of the pure oil 
on the refractometer scale. The refractometer reading of pure cottonseed 
oil is almost five degrees higher than that of pure olive. 

READINGS ON ZEISS REFRACTOMETER OF OLIVE AND COTTONSEED 

OILS.* 





Scale Reading. 




Scale Reading. 


Temperature 
(Centigrade). 




Temperature 








(Centigrade). 








Olive Oil. 


Cottonseed Oil. 




Olive Oil. 


Cottonseed OiL 


35-0 


57-0 


61.8 


25-5 


62.4 


67-5 


34-5 


57-2 


62.1 


25.0 


63.0 


67-9 


34-0 


57-4 


62.3 


24-5 


63-3 


68.2 


33-5 


57-7 


62. s 


24.0 


63-6 


68.5 


33-0 


■58.0 


62.8 


23-5 


63-9 


68.8 


32-5 


58.3 


63.0 


23.0 


64.2 


69.1 


32.0 


58.5 


63.2 


22.5 


64-5 


69-4 


31-5 


59.0 


63.6 


22.0 


64.8 


69.7 


31.0 


59-2 


64.0 


21-5 


65.1 


70.0 


30-5 


59-4 


64.2 


21.0 


65-4 


70-3 


3D.0 


59-9 


64-5 


20.5 


65-7 


70.6 


29.^ 


60.1 


64.9 


20.0 


66.0 


70.9 


29.0 


60.3 


65.1 


19-5 


66.3 


71.2 


28.^ 


60.6 


65-3 


19.0 


66.6 


71-5 


28.0 


60.9 


65-7 


18.5 


66.9 


71-8 


27-5 


61. 1 


66.0 


18.0 


67.2 


72.1 


27.0 


61-5 


66-5 


17-5 


67-5 


72-4 


26.5 


62.0 


67.0 


17.0 


67.8 


72-7 


26.0 


62.2 


67-3 


16-5 


68.1 


73-0 



The Elaidin Test, in the case of pure olive oil, is very distinct i\'c, since 
it yields by far the hardest elaidin of all the common oils, and solidifies 
the most quickly. 

Archbutt f shows the effect on this test of the mixture with olive oil 
of various proportions of rape and cottonseed oil, as follows: 



Kind of Oil. 


Minutes Required for Solid- 
ification at 25° C. 


Consistency. 


Olive oil 


230 

320 

From 9 to 1 1 ^ hours 

" 9 " Ili " 
More than 11^ " 


Hard but penetrable 


' ' + 10% rape oil ........... 


Buttery 


" -f20% " 




" -f 10% cottonseed oil 

" +20% " 


Very soft. 



♦ Ann. Rep. Mass. State Bd. of HeaUh, 1899, p. 647. t Jour. Soc. Chem. Ind., 1897, p. 447. 



EDIBLH OILS .4ND F/1TS. 515 

Cottonseed Oil as an adulterant is best detected by means of the Hal- 
phen or Bechi tests. Its presence in notable quantities increases the 
specific gravity, refractometer reading, and iodine number very materially. 
Its high Maumene figure is also distinctive. 

Peanut Oil, when present to a considerable extent, betrays its presence 
by its peculiar bean-like flavor. Most of the constants of peanut oil 
lie within the limits of olive oil, with the exception of the higher iodine 
number and refractometer reading. A considerable admixture of peanut 
oil raises, the refractometer reading perceptibly over that of pure olive. 
Its presence is best shown positively by tests for arachidic acid (p. 523), 
noting that traces of arachin have been reported in pure olive oil, insuf- 
ficient, however, to interfere with the detection of added peanut oil. 

Sesame Oil differs more particularly from olive in its higher specific 
gravity and iodine and Maumene numbers, and is readily detected by 
distinctive color tests (p. 519). 

Rape Oil is characterized by a much lower saponification value and 
higher iodine number than olive. 

Com Oil differs materially from olive in its exceedingly high iodine 
number and refractometer reading. Its specific gravity and saponifica- 
tion numbers are also higher. 

Lard Oil, when present in considerable quantity, is often rendered 
apparent by its characteristic odor on warming. Its low refractometer 
reading and iodine number are also distinctive. 

Poppyseed Oil differs most widely from olive oil in its refractometric 
reading, its high dispersion, and its Maumene number, which in the case 
of poppyseed is 87° and of olive about 42°. 

Cocoanut Oil in mixture with olive perceptibly raises the solidifying- 
point. When more than 12% of cocoanut oil is present, the sample will 
become solid when placed in ice water. 

Fish Oils, when present, are rendered apparent by reason of their 
strong taste and smell, and by their very high iodine number. Boiling 
the sample with sodium hydroxide develops a peculiar reddish colora- 
tion, when fish oils are present. 

Routine Examination of Olive Oil for Adulterants. — First note the 
smell and taste of the sample, and then take the refractometric reading. 
An abnormally high refraction indicates adulteration. Then test with 
strong nitric acid (p. 513)- If the refraction is normal, and the color 
resulting from the acid reaction a pale green, the presumption is that 
the oil is pure. Test first for cottonseed oil by the Halphen reaction, 



5i6 FOOD INSPECTION AND /IN A LYSIS, 

and then in succession try the various color reactions for sesame and rape 
oils. If all these are absent, and, by abnormal constants, or by color 
with nitric acid, there is reason to believe the oil is adulterated, determine 
carefully such of the constants as are most indicative, by their M^ide 
variation from olive, of poppyseed, mustard, and corn oils. 

If all these oils are presumably absent, and either a high refractom- 
eter reading or a color reaction with nitric acid still indicates adultera- 
tion, peanut oil is more than likely to be present, and should be tested for 
either by Renard's or Bellier's method. 

The edible oils and adulterants are arranged in order of their relative 
price about as follows: 

Olive oil. 

Peanut oil. 

Lard oil. 

Sesame oil. 

Poppyseed oil. 

Rape oil. 

Corn oil. 

Cottonseed oil. 

COTTONSEED OIL. 

Source and Preparation. — This oil, largely used as a table oil and as 
an adulterant of olive oil, is derived from seeds of the various species 
of the cotton plant, Gossipium, of which the most common are G. herha- 
ceum, native to Asia, but cultivated extensively in southern Europe and 
in the United States, G. arboreum, in Asia and Africa, and G. barbadense, 
in the West Indies. G. religiosum and hirsutiim are varieties of G. herb- 
aceum. 

The seeds are in reality a by-product in cotton manufacture. In 
shape they are irregularly oval, measuring from 5 to 8 mm. greatest diam- 
eter. The seed skin or pod is covered with the liber of the cotton. 

The seeds are first cleaned and separated from dirt by sifting machines, 
and from the fiber by specially constructed gins, after which they are 
cut into small pieces, freed from their hulls, crushed between rollers, and 
afterward submitted to hydraulic pressure in bags to express the oil, 
which is clarified by filtration or refined. The refining consists in wash- 
ing the crude oil with sodium hydroxide solution, whereby the impuri- 
ties are dissolved and thus removed. 

Nature and Composition of Seeds and Oil. — The seeds of the cotton 
plant are rich in oil, containing from 10 to 29 per cent, according lo the 



EDIBLE OILS AND FATS. 



517 



variety. Four samples of American cottonseed were found to be com« 
posed as follows, according to Brannt:* 



Constituents. 



South 
Carolina. 



Georgia 


Georgia 
II. 


10. 1 


9-8 


16.2 


17.1 


17.4 


17.2 


2.9 


3-2 


-9 


-7 


27-4 


26.1 


19.2 


19.8 


5-9 


6.1 



Georgia 
III. 



Water 

Cottonseed oil 

Nitrogenous compounds 

Ammonia-making compounds 

Gum, sugar, and soluble starch 

Cellulose, starch, and resin 

Ligneous tissue 

Ash (phosphate of lime, silica, alumina, 
iron, magnesia, potash, soda, etc.) 



9-5 
20. 1 
17.8 

2-3 

.8 
26.2 
17.6 



19.6 
18. 1 

3-7 

•9 

20. 7 

22.4 

6.4 



Refined cottonseed oil is a pale-yellow oil of thick consistency, possess- 
ing a bland though pleasant taste and odor. It consists of the glycer- 
ides of oleic, stearic, palmitic, and linoleic acids, and evidently also a small 
content of hydroxyacids, though this has not been investigated as yet. 

On cooling the oil to a temperature below 12° C. particles of solid 
fat will separate. At about 0° to — 5° C. the oil solidifies. When the 
oil is brought in contact with concentrated sulphuric acid, a dark, red- 
dish-brown color is instantly produced. 

U. S. Standards. — Cottonseed oil is the oil obtained from the seeds of 
cotton plants and subjected to the usual refining processes; is free from 
rancidity, has a refractive index (25° C.) not less than 1.4700 and not 
exceeding 1.4725; and an iodine number not less than 104 and not 
exceeding no. 

" Winter-yellow " cottonseed oil is expressed cottonseed oil from which 
a portion of the stearin has been separated by chilling and pressure, and 
has an iodine number not less than no and not exceeding 116. 

Cottonseed Stearin. — This product, used as an adulterant of lard 
as well as a substitute therefor, is obtained as a by-product in the manu- 
facture of winter-yellow cottonseed oil. It is a light yellow fat, resembling 
butter in consistency. 

Bechi's Silver Nitrate Test. — Hehner^s Modificaiion. — Two grams of 
silver nitrate are dissolved in 200 cc. of 95% alcohol free from aldehyde, 
40 cc. of ether are added, and the reagent made very slightly acid with 
nitric acid. 

In applying the test, a small quantity of the melted fat or oil is mixed 
in a test-tube with half its volume of the above reagent, and the tube is 
immersed in boiling water for fifteen minutes. With proper precautions 



* V'egetable Fats and Oils, p. 223. 



5lS FOOD INSPECTIOM AND ANALYSIS. 

the presence of cottonseed oil is indicated by a more or less strong reduc- 
tion of the silver, while an oil or fat free from cottonseed oil causes 
no appreciable reduction. 

Certain oils free from cottonseed that have become rancid or decom- 
posed, as well as fats that have been subjected to a high temperature, 
sometimes show a slight reduction with Bechi's test. In cases of doubt 
it is well to apply the test on the fatty acids as follows: 

MiUiau's Modification oj Bechi's Test* — Heat 20 grams of the 
sample with 30 cc. of alcohoHc potash' solution (20% potassium hydroxide 
in 70% alcohol), shaking at intervals till saponification is complete. 
Continue the heating for some minutes afterward until the alcohol is 
driven off, and dissolve the soap in 250 cc. of hot water. Add a slight 
excess of 10% sulphuric acid, and wash the separated fatty acids three 
times by decantation with water. Then proceed with a portion of the 
fatty acids as in Bechi's test. 

Halphen's Test. — This is a much more delicate test for cottonseed 
oil than either of the preceding, as little as 2% of cottonseed oil being 
rendered apparent in olive oil. A mixture is made of equal volumes 
of amyl alcohol and carbon bisulphide in which 1% of sulphur has been 
dissolved. From 3 to 5 cc. of melted fat are mixed with an equal volume 
of the above reagent in a test-tube, loosely stoppered with cotton, and 
heated in a bath of boiling saturated brine for fifteen minutes. If 
cottonseed oil is present, a deep-red or orange color is produced. In 
its absence little or no color is developed. 

Previous heating of the oil diminishes the delicacy of the Halphen 

test, and Holde and Pelgry t state that if cottonseed oil has been heated 

at 250° for ten minutes, it will fail to respond to the test. Fulmer finds 

that it is necessary to heat to 265 to 270° to render it wholly inactive to 

the test. 

SESAME OIL. 

Sesame or benne oil is pressed from the seeds of Sesamum indicum 
and S. orientale, both of which are now regarded as varieties of the same 
species, and S. radiatwn. These plants are native to southern Asia, but 
now cultivated in nearly all tropical countries. The larger portion of 
commercial sesame oil is manufactured in England, France, Germany, 
and Austria. 

The seeds are yellow to dark brown, and in some cases black, inclined 
to the oval in form, the average longest diameter being about 4 mm. 

*Monietur Scientifique, 1888, p. 366. f Jour. Soc. Chem. Ind., 18, 1899, p. 711. 



EDIBLE OILS AND FATS. 



519 



The seeds are commonly subjected to cold pressure once, and after- 
wards twice pressed when warm, thus yielding three grades of oil. From 
47 to 60 per cent of oil is contained in the seeds. 

According to Brannt* the composition of sesame seeds is as follows: 





Sesamum 
Orientale. 


Sesamum 
Indicum. 


Oil 

Organic substances 

Protein therein 

Nitrogen therein 

Ash 


55-63 
30-95 

2I-42 

3-39 

7-52 

3-90 


50-84 

35-25 

22-30 

3-56 
6.85 
7.06 


Water 




100 -GO 


100.00 



Sesame oil consists of the glycerides of oleic, stearic, palmitic, and 
myristic acids. It is golden yellow in color, free from odor, and pos- 
sesses a delicate and characteristic flavor, on account of which the 
highest grades are by some considered equal to olive oil as a condiment. 
It is accordingly sold to some extent as an edible oil. It was formerly 
used as an adulterant of olive oil, but has of late years been largely dis- 
placed by cheaper oils for purposes of adulteration. When cooled to 
— 3°C., sesame oil congeals to a yellowish- white mass. Concentrated 
sulphuric acid converts it into a brownish-red jelly. 

U. S. Standards. — Refractive index (25°) 1.4704 to 1.4717; iodine 
number 103 to 112. 

Adulterants to be looked for in sesame oil are cottonseed, poppy- 
seed, corn, and rape oils. 

Tocher's Test.f — One gram of pyrogallic acid is dissolved in 15 cc. 
of concentrated hydrochloric acid and mixed with 15 cc. of the sample 
in a separatory funnel. After standing for a minute, the aqueous solu- 
tion is withdrawn and boiled. If sesame oil is present, the solution 
showT; a red coloration by transmitted, and blue by reflected, light. 

Baudouin's Test. J — Dissolve o.i gram of cane sugar in 10 cc. of hydro- 
chloric acid (specific gravity 1.20) in a test-tube, and shake thoroughly 
with 20 grams of the oil to be tested for one minute. Then allow the 
mixture to stand. The aqueous solution quickly separates from the oil, 
jind in the presence of 1% or more of sesame oil will be colored deep red. 

Certain pure Tunisian and Algerian olive oils have been found to 
£ause a slight coloration with this test, but of a different shade from sesame. 
Moreover, if the test is applied to the fatty acids, no coloration in the case of 
olive oil is produced, while with sesame the color is the same as with the oil. 



* Vegetable Fats and Oils, p. 251. f Chem. Zeit. Rep., 5, i^ 

J Zeits. angew. Chem., 1892, p. 509. 



)i,P- 15- 



520 



FOOD INSPECTION AND ANALYSIS. 



Villivecchia and Fabris Test.* — This test was suggested on account 
of the fact that the color reaction in the Baudouin test was attributed to 
the agency of the levulose produced by the inversion of the sugar by 
hydrochloric acid. As furfurol is the chief product of the reaction between 
levulose and hydrochloric acid, it was substituted as follows: Dissolve 2 
grams of furfurol in ico cc. of 95% alcohol, and shake o.i cc. of this solu- 
tion in a test-tube with 10 cc. of the oil to be tested and 10 cc. of hydro- 
chloric acid (specific gravity 1.20) for half a minute. The aqueous 
layer, on settling out, will be colored deep red, if sesame is present. 

Or 0.1 cc. of the alcohol furfurol solution is mixed with 10 cc. of 
oil and i cc. of hydrochloric acid in a separatory funnel, shaken well, 
and the separation aided by the addition of chloroform, which causes 
the aqueous layer, showing color with sesame oil, to float. 

Since furfurol produces with hydrochloric acid alone a violet colora- 
tion, it is necessary to use it in dilute solution as above. 

RAPE OIL. 

Rape or colza oil is expressed from the seeds of the Brassica or rape- 
plant, of which there are three principal varitics, Brassica napus, B. cam- 
pestris, and B. rapa, one or another of which are cultivated in nearly 
every country of Europe, excepting Greece. Large amounts are also 
grown in India and China. The seeds arc small, round grains, from 
2 to 2.5 mm. in diameter, yielding from 30 to 45 per cent of oil. The 
seeds, according to Brannt,t have the following average composition: 





Fresh Seeds. 


Old Seeds. 


Oil 


36.80 
49-30 

2.50 

4.80 

9.10 


38-50 
53-25 

3-II 

3-90 

4-35 


Organic substances 

Nitrogen therein 

Ash 


^Vater 




100.00 


100.00 



In the process of preparation the seeds are first crushed, and the oil 
removed by pressing or extraction. The crude oil is of a brownish- 
yellow color, and when fresh is almost free from taste and smell, so that 
it serves, when cold pressed, as an edible oil, or an adulterant of such 
oils. It develops a disagreeable and peculiar taste and odor on long 
standing, due to the presence of certain albuminous and mucilaginous 
substances which it contains. These may be removed by refining, usually 
by treatment with sulphuric acid, but the refined oil has an unpleasant 
taste and odor. 



* Jour. Soc. Chem. Ind., 1894, pp. 13-69. 



t Vegetable Fats and Oils, p. 240. 



EDI BLR OILS AND FATS. 



521 



The principal components of rape oil are the glycerides of stearic, 
oleic, erucic, and rapic acids. The chief adulterants are cottonseed 
and poppyseed oils. 

Palas Test for Rapeseed Oil.* — Mix in the cold 30 cc. of a 1% solu- 
tion of fuchsin, 20 cc. of sodium bisulphite (specific gravity 1.31), 200 cc. 
of water, and 5 cc. sulphuric acid. If the sample of oil to be tested be 
shaken with the reagent, a rose-red coloration is obtained in the presence 
of rape oil, said to be delicate to the extent of detecting 2% of the oil in 
mixtures. 



CORN OR MAIZE OIL. 

Com oil is derived from the seed of the American grain Zea mays, or 
Indian com, the constitution of the yellow and white varieties of which 
is, according to Andes,t as follows: 





Yellow a,rn. White O^rn, 
Per Cent. Per Cent. 


Organic matter 

Starch 

Albuminoids 


82.93 

61.95 
10.71 
1.32 

9-50 
6.25 


80.76 

62 . 23 
9.62 
1.04 
10.60 
7.60 

100.00 


Ash 


Water 


Oil 




100.00 



Nearly all the oil is contained in the germ of the seed, the oil con- 
stituting in fact over 20% of the germ. Corn oil consists chiefly of the 
glycerides of palmitic and oleic acids. There is some doubt as to the 
presence of stearin. It is golden yellow in color, and possesses a pleasant 
odor and taste, resembling in flavor freshly ground grain. 

It is prepared by suVjjecting to hydraulic jjressure the germ separated 
in the manufacture of starch and of glucose, the germs yielding about 
15% of pure oil. While most of the oil of commerce is a by-product 
from starch and glucose factories, a small amount is recovered from the 
residue of fermentation vats in the manufacture of alcohol. Com oil is 
coming to be used more and more as an adulterant of olive oil, and, 
according to Lewkowitsch, of lard. 

It Is claimed by Hopkins, | by Hoppe-Seyler, and others, that com oil^ 

* Analyst, XXII, p. 45. 

f Vegetable Fats and Oils, p. 131. 

X Jour. Am. Chem. See., 1898, 20, p, 948. 



522 



rOOD lNSVECT;Ohl y^ND ANALYSIS. 



unlike most vegetable oils, contains cholesterol. Olive oil was long 
supposed to be unicjue as a vcgetaljle oil in containing this substance. 
Hopkins, on the assum[)tion that cholesterol occurs in corn oil, sug- 
gested that a test for corn oil as an adulterant of certain vegetable oils 
lay in the identification of cholesterol. 

Gill and Tufts * claim that, while the alcohol of corn oil is not phytos- 
tcrol. neither is it cholesterol, ])ut a tliird sul)stance, known as sitosterol,! 
occurring in wheat and rye. 

There arc no color reactions identifying corn oil as such. Its pres- 
ence in other oils is indicated only l)y lis influence on the various con- 
stants, the iodine number and refractometric reading especially being 
much higher than those of other edible oils. 

PEANUT OIL. 

Peanut or arachis oil is obtained from the seeds of the Arachis hypo- 
gcp.a (peanut, ground nut, or earth nut) cultivated in most tropical coun- 
tries, notably in South America, China, India, and Japan. The plant 
is a creeping herb, developing its blossoms in the axes of the leaves. The 
fruit buds grow down into the earth, where the fruit is ri])ened, forming 
the well-known peanuts of commerce, the composition of which, accord- 
ing to Brannt, is as follows: 





Per Cent. 


Per Cent. 


Oil 


37-48 
52.86 

27.25 

2.43 

7-37 


to 4T.63 
" 53-12 

27.85 
" 2.50 
" 2.75 


Organic substances 

Albumin therein 


Ash 


Water 




100.00 


100.00 



Peanut oil is composed chiefly of the glycerides of oleic, palmitic, 
hypogreic, and arachidic acids. The oil is extracted ])y pressure, the 
first cold-drawn oil being practically colorless, and possessing a pleasant 
taste suggestive of kidney beans. It is esi)ccially adapted for use as 
a salad or table oil. A second pressure of the moistened residue from 
the first yields an inferior oil, yellowish in color, also somewhat used 
for edible puq)oses, and sometimes commercially called "butterine oil." 

U. S. Standards. — Refractive index (25°) 1.4690 to T.4707; iodine 
number 87 to too. 

* Jour. Am. Chem. Soc, XXV, 1903. f Burian, Monatsh. Chcm., iS, 1897, p. 551. 



EDIBLE OILS AND EATS. 523 

Adulterants of peanut oil arc coUonsccd, jjoppysecd, rape, and 
sesame oils. Very little pure peanut oil is found in commerce in the 
United States. It is to be looked for as an adulterant of French and 
Italian olive oils. 

Characteristic Tests.— Peanut oil, when pure or nearly jjure, may 
as a rule be readily identified from other oils. When present in large 
admixture in other oils it is not difficult to detect, but when only a small 
amount is j)resent, in oli\'e oil for instance, its detection becomes a more 
troulilesome matter. 

This difficulty arises from the fact that the constants of peanut oil 
are nearly the same as those of olive, with the single exception of the 
refractometric reading. Furthermore, there is no readily applied color 
test identifying peanut oil. 

All the other common adulterants of olive oil, as cottonseed, sesame, 
corn, poppyseed, and rape oils, are readily identilied, when present in 
small amounts, either by special color tests, or by reason of the fact that 
certain of their constants (Hffer \'cry widely from those of olive oil. Much 
more care and j)recaution are necessary in dealing with small admixtures 
of peanut oil than with almost any other adulterant. 

The Renard Test * has long been in use for detecting and estimating 
peanut oil in mixtures. In its original form this test (hd not give entirely 
satisfactory results, and earlier led to some erroneous conclusions. In 
recent years, however, it has been so modified and imjjroved as to be 
capable of quite ]X)silivc results when carefully carried out. While 
arachin is said to occur in minute traces in olive oil, its presence is not 
sufficiently marked to interfere with the use of the Renard method in 
detecting any decided admixture of peanut oil. 

The following modification of the Renard method, devised by Tolman,t 
has been adopted by the A. O. A. C'.: 

Twenty grams of the oil are saponified in a 250-cc. I'>lenmeyer flask 
with 200 cc. of alcoholic ])otassium hydroxide (40 grams potassium 
hydroxide in 1 liter of 95% redistilled alcohol). Neutralize with dilute 
acetic acid, using phenol[)hthalein as an indicator, and wash into a 500-cc. 
flask containing a boiling mixture of 100 cc. water and 120 cc. 20% 
solution of lead acetate. 

l>()il for a minute and cool the contents of the flask by immersing 
in cold, or, jjreferably, ice water, whirling the flask occasionally so that 

* Comp. Reml., 73, iSyr, [). 1,150- 

t U. S. I)l'j>1. of Agri( ., Hur. of Choni., Hul. 65; also liul. 77, and Bui. 107 (rev.). 



524 FOOD INSPECTION AND ANALYSIS. 

the soap when cold adheres to the sides of the flask. The water and 
excess of lead acetate can then be poured out, leaving the soap in the 
flask. Wash by shaking and decantation, first with cold water and 
then with 90% alcohol. Add 200 cc. of ether, cork the flask, and allow 
to stand with occasional shaking till the soap is disintegrated, after which 
boil on a water-bath under a reflux condenser for five minutes. Cool 
the soap solution down to a temperature between 15° and 17°, and allow 
it to stand for about twelve hours. 

Filter and thoroughly wash the precipitate with ether, after which the 
soap in the filter is washed back into the original flask with a stream of 
hot water acidulated with hydrochloric acid. 

Add an excess of dilute hydrochloric acid, partially fill the flask with 
hot water, and heat until fatty acids form a clear oily layer. Fill the flask 
with hot water, allow the fatty acids to harden and separate from the 
precipitated lead chloride, wash, drain, repeat washing with hot water, 
and dissolve the fatty acids in 100 cc. of boiling 90% by volume alcohol. 
Cool to 15° C, shaking thoroughly to aid crystaUization. 

From 5 to 10 per cent of peanut oil can be detected by this method, as 
it effects a complete separation of the soluble acids from the insoluble, 
which interfere with the crystallization of the arachidic acid. Filter, 
wash the precipitate twice with 10 cc. of 90% alcohol, and then with 70% 
alcohol. Finally dissolve off the precipitate with boiling absolute alcohol, 
evaporate to dryness in a tared dish, dry and weigh. To the weight add 
0.0025 gram for each 10 cc. of 90% alcohol used in the crystallization and 
washing, if done at 15° C, and 0.0045 gram for each 10 cc. if done at 
20°. The approximate amount of peanut oil is found by multiplying the 
weight of arachidic acid by 20. 

Arachidic acid crystals thus obtained should be examined micro- 
scopically. The melting-point should lie between 71° and 72° C. 

Methods of J. Bellier.* — Qualitative Test. — Saponify i gram of the 
oil with 5 cc. of an alcoholic potash solution containing 85 grams po- 
tassium hydroxide per liter of strong alcohol, conducting the saponi- 
fication in a small Erlenmeyer flask on the water-bath. After saponi- 
fication, boil for two minutes, neutrahze with dilute acetic acid, using 
phenolphthalein as an indicator, and cool by setting the flask in Avater 
at a temperature of from 17° to 19°. x\fter a short time, a precipitate 
nearly always comes down. Then add to the solution 50 cc. of 70% 
alcohol, containing 1% by volume of strong hydrochloric acid (specific 

* Ann. Chim. Anal., 1899, 4, p. 49; Zeits. fiir untersuch. Nahr., 1899, 2, p. 726. 



EDIBLE OILS AND FATS. 525 

gravity 1.20). Cork the flask, shake vigorously, and again cool by setting 
the flask in the above cooling-bath. In the absence of a precipitate, the 
oil may be pronounced free from peanut. If 10% or more of peanut oil 
is present, a more or less characteristic precipitate forms, and often with 
less than 10% a cloudiness in the solution is perceptible after standing 
between 17° and 19° for half an hour. Pure oHve oil remains perfectly 
clear as a rule. 

A few varieties of olive oil from Tunis especially high in solid fat 
acids, as well as cottonseed oil and sesame oil, give similar turbidity on 
the addition of the 70% alcohol. To distinguish between these oils 
and peanut oil, heat the mixture on the water-bath till complete solution 
takes place, and again cool to 17° to 19°. In the case of peanut oil the 
cloudiness or precipitate again occurs to the same extent as before, while 
in the other cases the solution should remain clear or nearly so. 

Quantitative Determination. — Saponify 5 grams of the oil with 25 cc. 
of the above alcohoHc potash solution in a 250-cc. Erlenmeyer flask, 
neutralize exactly with acetic acid, and cool quickly in water. After 
standing an hour, pour upon a 9-cc. filter and wash the precipitate with 
70% alcohol containing 18% by volume of hydrochloric acid, the tem- 
perature of the solution being not less than 16° nor more than 20°. Con- 
tinue the washing till the wash water no longer shows turbidity when 
diluted with water. 

Dissolve the precipitate in 25 to 30 cc. of hot 95% alcohol, dilute with 
water until the alcohol is 70%, let stand in water at 20°, filter, wash with 
70% alcohol, dry at 100°, and weigh. 

Bellier states that he has recognized with certainty as small an admix- 
ture as 2% of peanut oil by this method. 

MUSTARD OIL. 

The fixed oil of mustard is a by-product expressed from the seeds 
of the black and white mustard {Sinapis nigra and S. alba) in the process 
of preparation of mustard flour as a spice. The seeds contain from 
25 to 35 per cent of oil. 

Mustard oil somewhat resembles rape in composition, containing 
glycerides of erucic, behenic, and probably rapic acid. 

Black mustard oil is brownish yellow in color, having a mild flavor, 
and an odor but sUghtly suggestive of mustard. White mustard oil is 
golden yellow, and has a somewhat sharp taste. 



526 



FOOD INSPECTION /1ND ANALYSIS. 



Mustard oil is an alleged adulterant of edible oils, though by no means 
a common one. 



POPPYSEED OIL. 

This oil is obtained from the seeds of the opium poppy {Papavcr 
somnijerum), native in the countries east of the Mediterranean, and cul- 
tivated extensively for opium and for oil in all parts of Europe, Asiatic 
Turkey, Persia, Egypt, India, and China, \losi of the oil of commerce 
comes from France and Germany. 

There arc two chief varieties of poppy, the black (P. nigrum) and 
the white (P. album), the finest oil being produced from the white. The 
seeds arc somewhat flattened in form and kidney-shaped, yielding from 
40 to 60 per cent of oil. According to Brannt the seeds have the follow- 
ing composition: 





WhitL' P.ipi.y- 
secd. 


Black Poppy- 
seed. 


Oil 


55-62 
32.11 

16 89 

3-42 

8.85 

100.00 


51-36 
35-14 

17-50 
4.00 

9-50 


Organic substances 

Protein therein 

Ash 

Water 




100.00 



The oil is obtained by crushing the seeds and applying pressure. 
The best grade of cold-drawn oil is pale yellow in color, possessing a 
pleasant taste when fresh, and being practically free from odor. Lower 
grades shade into deeper yellow and even reddish color, possessing a 
strong taste and odor. Poppyseed oil is much used in Europe as a table 
oil, and does not readily turn rancid. It is composed of the glycerides of 
stearic, palmitic, and linoleic acids. Poppyseed oil has been used to some 
extent as an adulterant of olive oil. It is itself not infrequently adulter- 
ated with sesame oil. 



SUNFLOWER OIL. 



Sunflower oil is derived from the seed kernels of the plant of the same 
name {H elianthus annuus), originally grown in Mexico, but now culti- 
vated most extensively on a commercial scale in southern Russia. 



EDIBLE OILS yIND FATS. 



sn 



According to S. M. Babcock * the composition of sunflower seeds 
is as follows: 





Air-flry. 


Dried. 


Water 


12.68 

3.00 

15.88 

2Q.2I 
18.71 
20.52 


3-43 
18.19 

33-45 
21-43 
23-50 


Ash 


Albuminoids (N X 6.25) 

Crude iibcr 


Nitrogen-free extract 

Fat (ether extract) 


100.00 


100.00 



The seeds arc long, black, and oval in shape, yielding from 18 to 28 
per cent of oil. The liquid fatty acids of sunflower oil consist for the 
most part of linolcic, but little oleic acid being found. 

The seeds are first shelled, then crushed, and finally submitted to 
pressure both cold and hot. 

Sunflower oil is pale yellow in color, has a mild, pleasant taste, and 
is nearly free from odor. The cold-drawn oil is the variety most used 
for edible and cuhnary purposes in Russia, and as an adulterant of olive 
oil. Its use as an adulterant is, however, limited, and the writer has no 
knowledge of its having been found in olive oils used in the United States. 



ROSIN OIL. 

Rosin oil is prepared by the distillation of common rosin, and is an 
alleged adulterant of olive oil. It may be detected when present by 
shaking i to 2 cc. of the sample with acetic anhydride while warming. 
Cool, remove the anhydride by a pipette, and add a drop of sulphuric 
acid (specific gravity 1.53). Rosin oil gives a fugitive- violet color. f 

Cholesterol also responds to this color reaction. 

Renard's Test for Rosin Oil. — Prepare a solution of stannic bromide 
by allowing dry bromine to fall drop by drop upon tin in a dry, cool flask, 
and dissolving the product in carbon bisulphide. 

Add a drop of this reagent to i cc. of the oil. In presence of rosin 
oil a violet color will be produced. 

Polarization Test for Rosin Oil.f — The oil is dissolved in definite 
proportion in petroleum ether, and polarized in a 200-mm. tube. Rosin 



* The Sunflower Plant, its Cultivation, Composition, and Uses. 
Div. of Chem., Bui. 60, p. 18. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 32. 



U. S. Dept. of Agric, 



528 



FOOD INSPECTION /tND /IN A LYSIS. 



oil polarizes from + 30 to + 40 on the cane sugar scale, while other oils 
have a reading between + 1 and — i. 



COCOANUT OIL. 

Cocoanut oil is the fat expressed from the kernels of the cocoanut 
or fruit of the cocoa palm {Cocos nucljera), indigenous to the South Sea 
Islands and to the East-Indian archipelago, but grown in many tropical 
countries. 

It is sometimes known as "copra oil," from the copra or pulp, which 
contains from 60 to 70 per cent, of fat. According to Brannt, the com- 
position of the pulp is as follows: 



Indian Copra. 



Oil 

Organic substances 

Albuminous substances 

Ash 

Water 



68.7s 
23-65 

r-45 
6-15 



9.16 



African Copra. 



66.80 

25-25 

1-50 
6.45 



In the preparation of the oil the moist copra is separated from the 
shell, crushed in mortars and subjected to pressure, yielding a milky 
mass. This is then heated in boilers, and the oil which rises to the sur- 
face is removed by skimming. 

In some localities the pulp is first dried and then pressed. 

Cocoanut oil is usually white and possesses a mild taste and pleasant 
odor. The cold-drawn Malabar oil is of greenish color, and is used by 
the natives as an edible oil or substitute for butter. This variety is seldom 
found in commerce. 

Cocoanut oil contains, besides palmitin and olein, large proportions 
of myristin and laurin. Unlike the other vegetable oils, it contains also 
notable quantities of the glyceridcs of the volatile fatty acids caproic, 
capric, and caprylic, hence the high saponification value and Reichert 
number. The most characteristic constant is the Polenske number. 
The oil is rarely adulterated. 

Cocoanut oil easily becomes rancid. According to Andes, crystals of 
cocoanut oil appear under the microscope as a thick network of long 
needles. 



EDIBLE OILS /iND FATS. 529 

COCOA (CACAO) BUTTER. 

This preparation is not, properly speaking, in itself an edible fat. It 
is a by-product in the manufacture of cocoa, being removed by pressure 
from the crushed and ground cocoa nibs. The fat in cocoa beans varies 
from 36 to 50 per cent. The expressed fat is yellowish white, of a tallow- 
like consistency, has a pleasant taste and an odor suggestive of chocolate. 
It keeps a long time without turning rancid. In composition it consists 
of the glycerides of stearic, palmitic, and lauric acids, with traces of the 
glycerides of arachidic and butyric acids. 

Its demand for pharmaceutical purposes is, however, sufficiently great 
to render the use of cocoa-butter as an adulterant of food-fats extremelv 
rare. It should be borne in mind as a possible adulterant in examining 
various oils. 

It is subject to adulteration with paraffin, tallow, and cottonseed 
stearin. 

TALLOW. 

The rendered fats of various animals, especially the cow and sheep, 
constitute what is generally known as tallow. The untreated fatty tis- 
sues are more properly known as suet, the tallow being the clear fat 
separated entirely by heat from the cellular material. 

Tallow consists almost entirely of olein, palmitin, and stearin. Mut- 
ton tallow is usually, but not always, harder than beef tallow. 

Excepting in the manufacture of material for oleomargarincj wherein 
the heart and caul fats of beef are almost exclusively used, the fats from 
different parts of the animal are not, as a rule, separated. 

Fresh tallow has very little free fatty acid, but when it becomes rancid, 
the fat contains sometimes as high as 12% of free acid, reckoned as oleic. 

Tallow is of chief interest to the food analyst in connection with its 
use as an adulterant of lard. 

BUTTER. 

Nature and Composition. — Butter is the product obtained by the 
churning of cream or milk, whereby the fat particles are caused to adhere 
together into a compact mass, inclosing a certain portion of the casein, the 
excess of milk serum being subsequently largely removed by washing and 
mechanical working. 



530 



FOOD INSPECTION AND ANALYSIS. 



Butter fat is of extremely complex composition, containing a larger 
variety of glycerides than any other fat. Besides olein, })almitin, and 
stearin, the usual glycerides of the insoluble or fixed fatty acids found 
in most fats, butter contains notable quantities of the glycerides of a 
number of the volatile fatty acids, chief among which are butyrin, caproin, 
caprin, and capr\'lin, to which arc due its distinctive taste, and which 
by exposure to light and air readily become decomposed into their fatty 
acids — butyric, caproic, capric, and capr>dic, respectively. This decom- 
position in butter causes, or, more properly speaking, accompanies, what 
is commonly known as "rancidity." 

The process of separation of butter fat into its component glycerides 
is a matter of extreme difliculty, and results obtained by different chemists 
vary widely. Separation has been attempted by fractional distillation, 
by methods depending on the difference in chemical affinity of the various 
acids, and on the difference in solubility of the various lower homo- 
logues in water at different temperatures.* 

According to Hrowiu', the composition of butter fat is as follows: 



Acid 

Dioxvstearic. . 

Oleic 

Stearic 

I'ainiitic 

Myristic 

Laurie 

Capric 

Capryiie 

Caproic 

Butyric 

Totals . . . . 



Percentage of 
Acid. 



Percentage of 
Triglycerides. 



I.OO 
32.50 

1.83 
38.61 

9.89 

2-57 
0.32 
0.49 
2.09 
5-45 

94-75 



1 .04 

33-95 
1.91 
40.51 
10.44 
2-73 
0-34 
0-S2, 
2.32 
6.23 



Upwards of 300 analyses of butter are summarized by Konig in the 
following table: 





Water, 
Per Cent. 


Fat, 
Per Cent. 


Casein, 
Per Cent. 


Milk, 
Per Cent. 


Sugar, 
Per Cent. 


Lactic Acid, 
Per Cent. 


Salts, 
Per Cent. 


Minimum 

Maximum 

Mean 


4-15 
35-15 
13-59 


69.96 
86.15 
84-39 


0.19 
4.78 
0.74 


0.50 


0.45 
1. 16 


0.12 


0.02 

i=;.o8 

0.66 







* Browne, \ Contribution to the Chemistry of Butter Fat, Jour. Am. Chem. Soc., 21, 
1899, p. 807. 



F.DIBLR OILS AND FATS. 531 

Effects of Feeding Oil Cakes on the Composition of Butter. — Experi- 
ments have shown that the substance which causes cottonseed oil to respond 
to the Halphen test passes into the milk fat on feedingcows with cottonseed 
cake, but the substance that gives the Baudouin reaction is never carried 
into the milk on feeding with sesame cake. A number of investigators 
have found that feeding with cocoanut cake raises somewhat the Polenske 
number of the milk fat. There is good evidence, however, that, while 
the addition of vegetable oils to butter introduces phytosterol, as detected 
by Bomer's phytosterol acetate test, this substance can not be introduced 
into the milk fat b)- feeding. These facts should be borne in mind in the 
examination of butter for foreign fats, 

ANALYSIS OF BUTTER, 

Preparation of the Sample, — A. O. A. C. Method* — If large quan- 
tities of butter are to be sampled, a butter-trier or sampler may be used. 
The portions thus drawn, about 500 grams, are to be perfectly melted 
in a closed vessel at as low a temperature as possible, and when melted, 
the whole is to be shaken violently for some minutes till the mass is homo- 
geneous, and sufficiently solidified to prevent the separation of the water 
and fat. A portion is then poured into the vessel from which it is to be 
weighed for analysis, and should nearly or quite fill it. This sample 
should be kept in a cold place till analyzed. 

Water.— ^. O. A. C. Method. — About tw^o grams of the sample are 
weighed in a flat -bottomed platinum dish, such as is used for determining 
water in milk, and the dish and its contents kept in contact with the live 
stream of a water-bath till a constant weight is attained. 

Patrick's Rapid Method.-^ — This method is es])ecially suited for the 
use of dairymen, inspectors and others not provided with laboratory 
facilities. 

Ten grams of the thoroughly mixed butter are weighed into a 250-cc. 
aluminium beaker, which, together with a glass rod has been previously 
tared, and boiled over (but not in) the flame of an alcohol lamj) provided 
with a conical asbestos chimney, holding the beaker by means of a wire 
clamp in a nearly horizontal jjosition to avoid loss from spattering or 
foaming, and whirling constantly to prevent overheating. The rod 
serves to break up lumps of curd which form, thus facilitating the drying. 



* U. S. Dept. of Agric, Bur. of Chein., Bui. 46, p. 43; Bui. 107 (rev.), p. 123. 
t Jour. Am. Chem. Sor., 28, 1906, p. 161 1; 29, 1907, p. 1126. 



53-' 



FOOD INSPECTION AND ANALYSIS. 



The heating should be so conducted as to avoid any considerable dis- 
coloration of the curd. With suit- 
able heating the water may be re- 
moved in less than 15 minutes, 
after which the beaker is cooled in 
water and weighed. A balance 
sensitive to 10 milligrams, such 
as is used in weighing cream for 
testing by the Babcock method, is 
sufiicicntly accurate for weighing 
the butter. 

Gray's Method.'^ — i. The Spe- 
cial Apparatus for this method, 
shown in Fig. 100, consists of a flask 
{A) connected by a close-fitting 
rubber stopper {B) with a gradu- 
ated tube (C), and this in turn 
with a condenser jacket (£) by a 
rubber stopper {D). The tube C 
is closed by a glass stopper, the 
zero mark being the end of the 
stopper. Each mark of the grad- 
uation represents 0.02 cc. or, when 
10 grams of butter are used, 0.2%. 
2. Process. — Weigh 10 grams 
of the well mixed butter on a 
piece of parchment paper 13 cm. 
square, introduce into the flask, 
and add 6 cc, of a mixture of 5 
parts of amyl acetate and i part 
of amyl valerianate, free from 
water-soluble impurities. Connect 
the apparatus as shown in Fig. 
100, fill the condenser jacket with 
cool water to within 2.5 cm. of the 
top, and remove the glass stopper 
F. Heat the flask over a Bunsen 
burner, thus melting the butter and boiling the water. Watch the con- 




FiG. 100. — Gray's Apparatus for the Rapid 
Determination of Water in Butter. 



* U. S. Dept. of Agric, Bur. of Animal Ind., Circ. loo. 



EDIBLE OILS AND FATS. 533 

densation of the steam in the graduated part of the tube C, and do not 
allow the steam to get higher than the 15% mark. In case of continued 
foaming, allow the mixture to cool, add 2 cc. of the amyl reagent, and 
continue heating. After the water in the sample has boiled out, the 
temperature rises and the amyl reagent boils, driving the last traces of 
water and water-vapor from the flask and bottom of the stopper. Some 
of the amyl reagent is carried into the tube C with the steam, and some 
is boiled over after the water has been driven off. This amyl reagent 
in the tube is no disadvantage. When the mixture in the flask becomes 
a brown color and all the crackling noises in boiling cease, which usually 
requires 5 to 8 minutes, it is safe to conclude that all water has been 
driven from the flask. 

Disconnect the flask A from the stopper B, place the glass stopper F 
in the tube C, giving it a turn to insure its being held firmly; invert the 
tube C, first being sure that the mouth of the small tube inside the bulb 
is held upwards, pour the water from the condensing jacket E, and remove 
the jacket. When the tube C is inverted, the water and reagent flow 
into the graduated part of the tube. To separate these and to get the 
last traces of water down into the graduated part, the tube C is held with 
the bulb in the palm of the hand, and the stoppered end aw^ay from the 
body, raised to a horizontal position, and swung at arm's length sharply 
downward to the side. This is repeated a number of times until the 
dividing line between the water and reagent is very distinct, and no reagent 
can be seen with the water or vice versa. The tube should then be held 
a short time with the stoppered end downward, and the amyl reagent in 
the bulb agitated in order to rinse down any adhering water. 

The reading should not be taken until the tube and contents have cooled 
so Httle warmth is felt. When 10 grams of butter are used, the percentage 
is read directly at the lower meniscus. 

With butter very low in moisture it may be desirable to use 15 grams, 
and with butter very high, 5 grams. 

Fat. — This may be determined either directly or indirectly. For 
the direct determination, a weighed amount of the sample, from 2 to 3 
grams, is first dried at 100° in sand or asbestos, contained in a thin and 
fragile round-bottomed evaporating-shell (Hoffmeister's Schalchen). If 
desired, the moisture may be determined in this connection by loss in 
weight after drying. The shell is afterwards inclosed in a piece of fat-free 
filter-paper, and crushed in pieces between the fingers in such a manner 
as to avoid loss. The pieces are gathered in a mass and folded together 



534 FOOD INSPECTION AND ANALYSIS. 

in the filter-paper to form a packet of a size readily transferable to a 
Soxhlet extractor, in which the fat is removed in the usual manner and 
weighed, after drying, in a tared flask. 

Or, the fat may be indirectly determined by subtracting the sum of 
the water, casein, and ash from too. 

Casein. — The residue from the determination of water by the 
A .0. A. C. method is stirred with i)ctroleum ether until the fat is dissolved, 
and transferred to a tared Gooch crucible. After thorough washing with 
petroleum ether, the crucible is dried at ioo°, cooled, and weighed, thus 
obtaining the casein and ash. The loss on ignition at a dull red heat 
represents the casein. 

If desired nitrogen may be determined in the residue after removal of 
the fat with petroleum ether, and casein calculated from the nitrogen, 
using the factor 6.37. 

Ash. — The residue left on the Gooch crucible after ignition, obtained 
as described in the preceding section is the ash. It consists largely of 
salt, which may be calculated from the percentage of chlorine determined 
by titration. 

Milk Sugar and Lactic Acid compose most of the undetermined 
matter remaining after deducting from the total solids the sum of the 
fat, casein, and ash. Determine milk sugar, if desired, in an aqueous 
extract of the butter by Fehling's solution. 

Determination of Salt. — In a tared dish or beaker weigh out about 
5 grams of butter, taking a gram or so at a time from different parts of 
the sample. Add hot water to the weighed pari, and after it has melted, the 
contents of the dish are poured into a separatory funnel, shaken and 
allowed to stand till the fat collects at the top, after which the underlying 
aqueous solution is drawn off into an Erlenmeyer flask, leaving the fat 
in the funnel bulb. Hot water is again added, and from ten to fifteen 
extractions are made, using about 20 cc. of water each time, all the water 
being collected in the Erlenmeyer flask. 

A few drops of a solution of potassium chromate are then added for 
an indicator, and the sodium chloride volumetrically determined by a 
standard silver nitrate solution. 

Salted butter contains from 0.5 to 6% of salt. 

Examination of Butter Fat. — The butter fat is best obtained free 
from curd and salt by filtering when hot, the sample being best melted 
in a beaker on the water-bath. The water, with the curd and salt, will 
settle to the bottom. The clear fat is then filtered at a temperature not 



EDIBLE OILS AND FATS. 535 

exceeding 50° C, and subjected to such examination as may be desired 

to determine its purity. 

U. S. Standard Butter Fat has a Reichert-Meissl number not less 

40° 
than 24 and a specific gravity not less than 0.905 at — 5 C. 

40 

ADULTERATION OF BUTTER. 

The artificial coloring of butter is an art practiced for so many years, 
and is so far in accord with the popular demand, that it can hardly be 
considered as an adulteration. The most recent custom of adding pre- 
servatives other than salt to butter is, however, very properly considered 
in most localities as reprehensible, unless the character and amount of 
the preservative be made clear to the purchaser by a suitable label. 

The most common and time-honored sophistication is the substitu- 
tion in whole or in part of foreign fat, as in the case of oleomargarine, 
and, more recently, in the fraudulent sale of renovated or process butter 
for the freshly made article. 

U. S. Standard Butter is butter containing not less than 82.5% of 
butter fat. By acts of Congress approved August 2, 1886, and May 9, 
1902, butter may also contain added coloring matter. 

Artificial Coloring Matter in Butter.— Formerly carrot juice 
and annatto were used almost entirely as butter colors. The carrot furnished 
\o the farmer a ready means of coloring his dairy butter, and its use was 
long in vogue for this purpose, before the commercial butter colors were 
available. Other vegetable colors, such as turmeric, marigold, saffron, 
and safflower, are vsaid to have been used for this purpose, but, with the 
possible exception of turmeric, the writer is not aware of authentic cases 
in which they have been found in recent years. While annatto as a butter 
cclor is still in use, it is rapidly giving place to various oil-soluble, azo coal- 
tar colors, which are admirably adapted to the purpose. All butter 
colcrs are now put on the market in solution in oil, usually cottonseed 
in this country and sesame in Europe. 

Detection. — Martin^ devised a general scheme, applicable for the 
detection of various colors in butter. His reagent consists of a mixture of 2 
parts of carbon bisulphide with 1 5 parts of ethyl or methyl alcohol. 25 cc. of 
this solution are shaken with about 5 grams of the butter to be tested, and, 
after standing for some minutes, the mixture separates into two layers, of 

* Analyst, 12, p. 70. 



5j6 FOOD INSPECTION AND /IN A LYSIS. 

which the lower consists of the fat in solution in the carbon bisulphide, 
while the upper is the alcohol, which dissolves out and is colored by the 
artificial dye employed. If saffron is present, the alcoholic extract will be 
colored green by nitric acid and red by hydrochloric acid and sugar. 

Coal-tar dyes, if present, may be fixed on silk or wool by boiling bits 
of the fiber in the alcoholic extract, diluted with water and acidulated 
with hydrochloric acid. 

Turmeric is to be suspected, if ammonia turns the alcoholic extract 
brown; marigold, if silver nitrate turns it black, and annalto, if on evapo- 
rating the alcoholic solution to dryness and applying to the residue a drop 
of concentrated sulphuric acid, a greenish-blue coloration is produced. 

Turmeric is further tested for in the residue from the alcoholic extract 
as above obtained, by boiling the residue in a few cubic centimeters of 
a dilute solution of boric acid (or a solution of borax acidulated with 
hydrochloric acid), and soaking a strip of filter-paper therein. On drying 
the paper, if it assumes a cherry-red color, turning dark olive by dilute 
alkali, the presence of turmeric is assured. 

Carrotin (the coloring matter of the carrot root) does not impart its 
color to the alcohol layer in Martin's test. Moore * has pointed out 
this exception, and shown that while with carrotin present the alcohol 
layer in Martin's test remains colorless, as in the case of uncolored butter, 
that when, however, a drop of very dilute ferric chloride is added, and the 
test-tube shaken, if carrotin be present, the alcohol will gradually absorb 
the yellow color from the butter. Care must be taken to avoid an excess 
of ferric chloride, as very little of this reagent will suffice. 

Allen states that a butter color commercially known as "carrotin" 
consists in reality of i part of annatto in 4 parts of oil. 

Detection of Annatto in Butter. — Treat 2 or 3 grams of the melted 
and filtered fat (freed from salt and water) with warm, dilute sodium 
hydroxide. After stirring, pour the mixture while warm upon a wet 
filter, using to advantage a hot funnel. If annatto is present, the filter 
will absorb the color, so that, when .the fat is washed off by a gentle stream 
of water, the paper will be dyed straw color. It is well to pass the warm 
alkaline filtrate two or three times through the fat on the filter to insure 
removal of the color. 

If, after drying the filter, the color turns pink on application of a 
drop of stannous chloride solution, annatto is assured. 

* Analyst, ii, p 163. 



EDIBLE OILS AND F/ITS. 537 

Detection of Coal-tar Colors in Butter. — Geislefs Method.'^ — A few 
drops of the clarified fat are spread out on a porcelain surface and a pinch 
of fullers' earth added. In the presence of various azo-colors, a pink 
to violet-red coloration will be produced in a few minutes. Some varieties 
of fullers' earth react much more readily with the azo-dyes than do others. 
In fact some do not respond at all. When once a satisfactory sample of 
this reagent is obtained, a large stock should be secured of the same variety. 

Low^s Method.^ — ^A small amount of material to be tested is melted 
in a test-tube, an equal volume of a mixture of i part of concentrated 
sulphuric acid and 4 parts of glacial acetic acid are added, and the tube 
is heated nearly to the boiling-point, the contents being thoroughly mixed 
by shaking; the tubes are set aside, and after the acid solution has settled 
out it will have been colored wine-red in the presence of azo-color, while 
with pure butter fat, comparatively no color will be produced. 

Doolittle's Method for Azo-colors and Annatto.f — The melted sample 
is first filtered. Two test-tubes arc taken and into each are poured about 
2 grams of the filtered fat, which is dissolved in ether. Into one test- 
tube are poured i or 2 cc. of dilute hydrochloric acid, and into the other 
about the same volume of dilute potassium hydroxide solution. Both 
tubes are well shaken and allowed to stand. In the presence of azo- 
dye, the test-tube to which the acid has been added will show a pink 
to wine-red coloration, while the potash solution in the other tube will 
show no color. If annatto has been used, on the other hand, the potash 
solution will be colored yellow, while no color will be apparent in the 
acid solution. 

Cornelison's Test for Artificial Colors. § — Melt 10 grams of the clear, 
dry fat, and shake well in a separatory funnel with 10 to 20 grams of 99.5% 
acetic acid. If the materials are too hot, the fat will dissolve, but at 
about 35° it separates cpiickly and almost completely. Draw oii the clear 
acid, and after noting its color, test by adding to one portion of 5 cc. a few 
drops of concentrated nitric acid, and to another portion a few drops of 
concentrated sulphuric acid. 

Natural yellow butter gives by this test a colorless extract, which 
remains colorless on adding nitric or sulphuric acid. The acid extracts of 
annatto, curcumin, and carrot are various shades of yellow, both before 

* Jour. Am. Chcm. Soc, 20, 1898, p. 110. 

t Ibid., 20, p. 889. 

X U. S. Uept. of Agric, Bur. of Chem., Bui. 65, p. 152. 

§ Jour. Am. Chem. Soc, 30, 1908, p. 1478. 



538 FOOD INSPECTION AND ANALYSIS, 

and after addition of nitric acid, while with sulphuric acid they take on 
a pink coloration on standing, which in the case of curcumin is very decided. 
Soudan I and butter yellow give pink extracts, which remain ]:)ink on 
adding the stronger acids, while cerasine orange G, yellow O.B., yellow 
A.B. and certain other coal-tar dyes give extracts of various shades of 
yellow, which on treatment with the heavy acids in some cases remain 
colorless, but in others become pink, while the oil globule which separates 
remains colorless or takes on a pinkish color according to the dye. 

PRESERVATIVES AND THEIR DETECTION. — Fresh or unsalted butter 
and renovated butter are often found with an added preservative, the 
one most commonly used for this purpose being the so-called " boric 
mixture " (borax and boric acid) already discussed under milk adultera- 
tion. Salted butter is occasionally, though not so often, found preserved. 
Other preservatives used in butter are formaldehyde, and salicylic and 
sulphurous acids. These latter are, however, rarely found. 

Boric Acid. — This, if present, is best detected in the aqueous solution 
that settles to the bottom when butter is melted at the temperature 
of the boiling water bath, the supernatant fat being decanted off. 
Richmond* claims to be able to distinguish free boric acid from borax 
as follows: If on applying turmeric-paper directly to the aqueous liquid 
the paper turns red, the color being especially evident on drying, free 
boric acid is indicated. As a confirmatory test the reddened turmeric- 
paper is treated with dilute caustic alkali, whereupon it turns a dark olive- 
green if boric acid is present. 

In the absence of a red color by the above test, or when this color is 
faint, the aqueous solution is acidified slightly with hydrochloric acid 
and the turmeric-paper applied as before. If borax be present to an 
appreciable extent, the red color will now be quite marked, even though 
not appealing before. In other words, testing with turmeric-paper with- 
out acidifying with hydrochloric acid shows, according to Richmond, 
a slight coloration due to the free acid alone, while the more intense color 
formed by first acidifying is due to the combined acid, or borax. 

Determination 0} Boric Acid. — Ten grams of the butter fat are 
weighed in a beaker and transferred with hot water to a separatory funnel 
in which the fat is extracted with 10 to 15 portions of hot water as 
described on page 534* The combined aqueous extract is evaporated 
to dryness in a platinum dish, the residue made alkaline, and ignited at 

* Dairy Chemistry, p. 254. 



EDIBLE OILS AND FATS. 



539 



a dull red heat. Boil the ash with water, filter, and wash with hot water, 
keeping the volume of the fihrate under 60 cc. Make sure that the solu- 
tion is perfectly neutral to methyl orange by treatment, if necessar}-, 
with sulphuric acid and tenth-normal alkali, add 30 cc. of glycerin, a 
few drops of the phenolphthalein indicator, make up to 100 cc, and 
titrate ^^-ith tenth-normal sodium hydroxide according to Thompson's 
method fp. ^27,). 

Butter being practically free from phosphates, the preliminar)- treat- 
ment for removing phosphoric acid in Thompson's method mav be 
omitted. 

Formaldehyde. — The aqueous solution from which the fat of the 
butter meked at low temperature has been poured off, is added to some 
milk previously found free from formaldehyde, and the test for the latter 
with hydrochloric acid and ferric chloride is tried directly in the milk. 

Salicylic Acid. — Detection. — See method Xo. 2 for detection in milk 
page 183. 

Determination 0} Salicylic Acid. — Method oj the Paris Municipal 
Laboratory. — Repeatedly exhaust 20 grams of butter in a separatory 
funnel vdxh a solution of s.odium bicarbonate, thus obtaining soluble 
sodium salicylate, if salicyHc acid be present. Acidulate the aqueous 
extract with dilute sulphuric acid, and extract with ether. Evaporate 
the ether, and to the residue add a little mercuric nitrate, forming a pre- 
cipitate nearly insoluble in water. Filter this off, wash the precipitate 
with water, and decompose into free salicylic acid with dilute sulphuric 
acid. Redissohe in ether, evaporate the solvent as before, and dr\' the 
residue at a temperature of 80° to 100°. Extract the residue ^^-ith petroleum 
ether, dilute the ethereal Hquid with an equal volume of 95% alcohol 
and titrate with tenth-normal alkah, using phenolphthalein as an indicator. 

I cc. of tenth-normal alkali =0.0138 gram salicylic acid. 

Sulphurous Acid.— The aqueous hquid, separated from the butter fat, 
is distilled, and the distillate treated with bromine water and barium 
chloride. A precipitate on the addition of the latter reagent indicates the 
presence of sulphurous acid or a sulphite in the butter. 

Glucose in Butter.*— Crampton states that glucose has been found by 
him in butter intended for export to tropical countries, added to pre- 

* Jour. Am. Chem. Soc, 20, 1898, p. 201. 



S40 FOOD INSPECTION AND ANALYSIS. 

vent decomposition. In one sample made for export to Guadeloupe 
he found over io% of glucose. 

For its detection or estimation lo grams of the sample are weighed 
out and transferred to a separatory funnel with hot water, and shaken 
out with successive portions of hot water. These are combined, and 
the aqueous extract made up to 250 cc. The reducing sugar may be 
determined by Fehling's solution or by polarization, using in the latter 
case alumina cream as a clarifier. While a slight reduction should be 
disregarded, any considerable reduction may be undoubtedly ascribed 
to glucose. 

BUTTER "FILLED" WITH WATER.— Various preparations have been 
placed on the market to aid in incorporating water with butter. So called 
" black pepsin " has been used for this purpose. By churning the butter 
with water and a certain amount of the preparation in such a manner 
as to destroy the grain, it is possible to introduce two or three times the 
normal amount of water. 

RENOVATED OR PROCESS BUTTER. 

This product is also variously termed " boiled," " aerated," and 
" sterihzed " butter. There are various modifications of the process of 
manufacture, but the object is to melt up and treat rancid butter in such 
a manner that for a time at least it is sweet. The following manner of 
treatment is typical, and shows in the main the necessary steps in carrying 
out the process, though details of manipulation tary in different localities. 

The butter is melted in large tanks surrounded with hot water jackets 
at a temperature varying from 40° to 45° C. By this means the curd 
and brine settle to the bottom, whence they are drawn off, while the lighter 
particles rise to the top in the form of a froth or scum and are removed 
by skimming. 

The clear butter fat is then, as a rule, removed to other jacketed 
tanks, and, while still in a molten condition, air is blown through it, which 
removes the disagreeable odors. The melted fat is then churned with 
an admixture of milk (more often skimmed) till a perfect emulsion is 
formed, after which it is rapidly chilled by running into ice cold water, 
with the result that it becomes granular in form. It is then drained 
and " ripened " for some hours, after which it is worked free from excess 
of milk and water, salted, and packed. 

Under some state laws this product, to be legally sold, must conform 
to rules of labeling as strict as those prescribed for oleomargarine. In 



EDIBLE OILS AND FATS. 541 

Other localities it may be sold with impunity. Not infrequently it is 
sold as choice creamery butter, and sometimes at the same price. 

U. S. Standard Renovated or Process Butter should contain not 
more than 16% of water, and at least 82.5% of butter fat. 

OLEOMARGARINE. 

According to the U. S. revenue laws, artificial butter composed wholly 
or in part of fat other than butter fat must be branded oleomargarine. 
The name butterine, although used in advertising matter, docs not have 
the sanction of the government. The product is commonly known in 
England as margarine. As a rule the oleomargarine of commerce is 
composed of refined oleo oil, usually churned up with neutral lard, milk, 
and a small amount of pure butter, the whole being salted and sometimes 
colored to resemble butter. Cottonseed oil and other vegetable oils arc 
also used to some extent. 
; Oleo oil is prepared from the fat of b^ef cattle somewhat as follows:* 
Immediately after the animals are killed the fresh intestinal and caul 
fat are removed and placed in tanks of water at a temperature of about 
80° F. From this water they are transferred to other tanks of cold w^ater 
and chilled until all animal heat is removed. The fat is then cut or 
hashed into small pieces and melted at about 150° F. in jacketed steam 
kettles, until the clear oil is separated from the connective tissue. 

This oil is then drawn off into vats, which, on account of the appear- 
ance of the oil on cooling, are called graining or seeding vats, where it 
is allowed to stand for twenty-four hours or more at a temperature of 
about 85° F. From these vats the semi-solid emulsion of oil and stearin 
is dipped into cloths, which are folded and placed in a press between sheets 
of metal and subjected to powerful pressure. By this means the oil 
is separated from the stearin, and is drawn into casks for export or for 
manufacture into oleomargarine. Large quantities are annually exported 
to Holland, where oleomargarine is manufactured, and either sold for 
consumption in that countr}', or re-exported to other countries in Europe. 

The oleo oil thus expressed is a mixture of olein and palmitin. When 
first prepared, it is a clear amber-colored fluid, free from odor or fatty 
taste. It is packed in tierces, and, when opened at ordinary temperature, 
is a light-yellow^ solid. 

The further process of manufacture of oleomargarine consists in 

* Report on Oleomargarine, Its ^lanufacture and Sale, 19th An. Report, Alass. St. Bd. 
of Health, 1887. 



542 FOOD INSPECTION AND ANALYSIS. 

the main of mixing the olco oil as above obtained with varying pro])or- 
tions of neutral lard, milk, and genuine butter, with or without added 
coloring matter, and churning the mixture at a temperature ab()\e the 
melting-point of the fats, the neutral lard having previously l)een cured 
for at least forty-eight hours in salt brine. Occasionally small (juantities 
of other vegetable oils, as cottonseed, peanut, or sesame, are included in 
the above mixture. After the churning, the whole mass is cooled by 
contact with ice water. The chilled mass is drained, and afterwards 
salted, worked, and given much the same treatment as butter. 

The com])osition of commercial oleomargarine varies loelween the 
following limits: 

Oleo oil 20 to 25% 

Neutral lard 40 " 45% 

Butter JO " 25% 

Milk, cream, salt, etc 5 " 30% 

Coloring of Oleomargarine. —The artificial coloring matters employed 
are the same as in the case of butter, and are similarly tested for. 

In many states oleomargarine cannot be k'gall\- sold when colored 
to resemble butler. Under other state laws coloring matter is allowable. 
The federal law and most state laws prescribe the most rigid rules for 
marking jmckages containing oleomargarine, with a view to affording 
the utmost protection to the producer of butter against the fraudulent 
sul)stitutit)n lliercfor. 

Crampton and Simon's Tests for Palm Oil.* -So called " butter 
oils," consisting of cottonseed oil to which has been added 2 to 5 per 
cent of palm oil are used to color oleomargarine. Tlie following tests 
serve for the detection of \)i\\m oil. 

Preparation of Sample. — The sample sliould be kept in a cool, dark 
place until tested, as exposure to air and liglit, or the presence of water, 
alcohol, ether or similar reagents interfere with the tests. Immediately 
before testing, the sample is filtered as (piickly as ])ossible at a temi)erature 
not exceeding 70° C. 

First Method. — Dissolve 100 cc. of the fat in 300 cc. of petroleum ether, 
and shake out with 50 cc. of 0.5% potassium hydroxide. Draw olT the 
watery layer, make distinctly acid with hydrochloric acid, and shake out 

* Jour. Am. Ctiem. Soc, 27, 1905, p. 270. 



EDIBLE OILS /1ND F/ITS. 543 

witli 10 cc. of colorless C. P. carbon letrachloridc. Separate the carbon 
lelrachloride solution, transfer a portion to a porcelain crucible, add 
2 cc. of a mixture of one part of colorless, crystallized C. P. phenol and 
2 parts 01 carbon tetrachloride, then 5 drops of hydrobromic acid (sp. gr. 
1. 19), and mix by gentle agitation.* 

The almost immediate develoj^ment of a Vjlui.sh-green color is indicative 
of palm oil. 

Second Me/hod. — Shake 10 cc. of the melted and filtered fat with an 
equal volume of colorless C. P. acetic anhydride, add one drop of sulphuric 
acid (sj). gr. 1.53), and shake a few seconds longer.f 

If palm oil be present, the lower layers on .settling out will be found 
to be colored blue with a tint of green. The color in this as in the preceed- 
ing test is transient. 

Of the edible oils only sesame and mustard oils give a similar color 
reaction. Sesame oil, after repeated extractions with alcohol, will not 
give the blue color, but cotton.seed oil containing as little as 1% of palm 
oil still responds to the test. 

Adulterants of Oleomargarine. — This product is liable to adultera- 
tion not only by the u.se of inferior and unwholesome fat, but bv the admix- 
ture in some cases of paraffin. J This .sophistication is made manifest, 
if an appreciable amount of the adulterant has been used, by the high 
melting-point and the low saponification number, as well as by the low- 
specific gravity. If a clear saponification is impossible under ordinary 
conditions, paraffin is to be suspected. It may be separated and quanti- 
tatively determined as described on j). 1510. 

Heaithfulness of Oleomargarine. — Under the directions of the Mas- 
sachusetts Board of Health, § a large number of artificial digestion experi- 
ments were made to show the relative nutritive value of butter and oleo- 
margarine, and at the same time the wholesomeness of oleomargarine 
as a food was carefully investigated. The general conclusions reached 
were that, when comparing the best grades of both products, there is 
little if any difference between butter and oleomargarine on grounds of 
digestibility, while a good oleomargarine is much to be preferred to a 



* Halphen uses a similar reagent to fletect rosin oil in mineral oil. Jour. Soc. Chem, 
Ind., 21, 1902, p. 1474. 

t The reagents are the same as used in the Liebermann-Stort h test for rosin oil. 

X Geissier, Jour. Am. Chem. .Soc, 21, 1899, p. 605. 

§ 19th An. Report, Mass. State Board of Health, 1887, p. 248. 



544 



FOni) INSrilCTION /IN!) ANALYSIS. 



poor butter from a nutritive standpoint. As to its wholesomeness, a 
large number of experts consulted were unanimous in expressing their 
favorable o[)inions of oleomargarine as a healthful article of food. 

When sold on its own basis in accordance with the law, it forms an 
excellent cheap substitute for butter. It is only when fraudulently sold 
as buKer or in violation of the various state and federal laws, that it 
comes wilhin the province of the health autliorities to condemn it, and, 
unfortunately, by reason of its close resemblance to the dairy product 
the temptation to sell it for what it is not is always great. 

Distinguishing Oleomargarine from Butter. — The two i)roducts, 
made uj) as they are of mixtures of the same fats, and differing for the 
most part only in the ])crcentage comjjosilion of these fats, show many 
jjropcrtics in common. T'or instance, the melting- j)oinl is so nearly the 
^ame for both ])r()ducts as to be of no use as a distinguishing indication. 
Other physical characteristics, as of taste and smell, are very similar in 
bo!]i products, except in llie hands of the expert. The microscope is 
of limited value, excepl in so far as it indicates that the fat has first been 
melted and af:,erwards solidified. 

From the fact that olco oil and nculnd lartl form by far the larger 
j)oriion of the mixture known as oleomargarine, the glycerides that make 
up the fat of the latter are chiefly those of the insoluble fatty acids, stearic, 
oleic, and palmitic. The percentage of volatile fatty acids present in 
oleomargarine is very small, and the presence of these volatile acids is 
due entirely to the adinixlurc of butter which it contains. This furnishes 
the most ready means of distinguishing chemically between the two 
products, and, as indicated by the Reicherl number, is the chief reliance 
of the analyst for couri evidence. 

Incidentally, as will be seen by the accompanying table, the refrac- 

CONSTANTS OF BUTTER FAT AND OLEOMARGARINE. 



Butter fat: 

Maximum. . 

Minimum . . , 
OlcomarKarine. 

Maximum. . 

Minimum . . 



0.8705 
.867§ 

.86255 
.8s8si 



:i.69J 
9-341 






89 . 6ot 

85 -Oat 



95 •451 
02.40 



S.94 
3.005 



51; I. .61 



S.62t 
0.00 J 

3.64t 
2-391 



875t 

3S0t 
3o63t 



2« 



3-iot 
0.49J1 



23.^ S 

222§ 



t' 



2038 
92S 



O H 

a; 

i5.8t 
12.4T 



S-Sl 
o.Sl 



A S C 

Sort 
+j rt cu 



* Number f){ cubic centimeters N/io alkali neutralizing volatile acids in 2.5 grams fat. 

t From analyses inade in Mass. State Board of Health laboratory. 

\ From analyses made in laboratory of U. S. Dcpt. of AKric, Bur. of Chem. 

i From analyses by A. H. Allen. 



EDIBI.R OILS AND FATS. 



545 



tomctcr reading, the iodine number, the saponification equivalent, and 
the specific gravity are all useful constants in indicating points of difler- 
cnce between the two fats, it being understood that in oleomargarine, 
as in butter, the fat for examination is melted and separated by filtra- 
tion or otherwise from the curd, salt, and other constituents. 

The constants for varying mixtures of butter wilh foreign fat as found 
by Villiers and Collin * are tabulaterl below. 

Odor and Taste, — It is easy with a little practice to become so 
accustomed to the odor and taste of oleomargarine, as to be able to pass 
judgment with considerable confidence by these senses alone, whether 
a sample in question is oleomargarine or butter. The distinction is 
rendered more apparent by melting a j)ortion of the sample on the water- 
bath. If the product is butter, either fresh or renovated, the butyric 
odor of the melted fat is very characteristic, while the melted oleomargarine 
not only is lacking in the butyric odor (a negative property), but possesses 
a distinctive "meaty" smell. peculiar to itself, which, while not unpleasant, 
is unmistakable. The flavor of oleomargarine to one experienced in dis- 
tinguishing between the two products is very apparent. This flavor, 
slight though it is, might be compared to that of cooked meat. 







Hehner's 


Soluble 


Koottstorfer's 


V-.latilc 






Number. 


Acids. 


Efjuivalcnt. 


Acids. 


Pure butter 


88 


5 


224 


26 


Butter, 95%; 


foreign fat, 5% 


88.35 


4.8 


222.6 


24.7 


" 90% 


'• " TO%.... 


88.70 


4.5 


221.2 


23-4 


" 85% 


" " 15%---- 


89.05 


4-3 


219.8 


22.2 


" 80% 


" " 20%.... 


89.40 


4.1 


218.4 


20.9 


" 75% 


" " 25%---- 


89-75 


3-9 


217 


19.6 


" 70% 


" " 30%.... 


90.10 


3-6 


215.6 


18.3 


" (>f/o 


" " 35%-- -■ 


90-45 


3-4 


214.8 


17.1 


" 60% 


" " 40%.... 


90 . 80 


3-2 


212.8 


15.8 


" 55% 


" " 45%---- 


91-15 


3 


211.4 


14-5 


" 50% 


" " 50%---- 


91-50 


2-7 


2ro 


13.2 


"• 45% 


" " 5S%---- 


91.85 


2-5 


208.6 


12 


" 40%. 


" " 60%.... 


92 . 20 


2-3 


207.2 


10.7 


" 35% 


" " 65%.... 


92-55 


2.1 


205.8 


9-4 


" 30% 


" " 70%.. •- 


92.90 


1.8 


204.4 


8.1 


" 25% 


" " 75%---- 


93-25 


1.6 


203 


6.9 


" 20% 


" " 80%.... 


93.60 


1-4 


201.6 


5-6 


" 15% 


" " 85%..-. 


93-95 


1.2 , 


200.2 


4-3 


" 10% 


" " 90%.... 


94-30 


0.9 


198.8 


3 


5/0 


" " 95%-- •• 


94-65 


0.7 


197.4 


1.8 


Foreign fat. , 




95 


0-5 


196 


0.5 








* Les Substances Alimcntaires, p. 731. 



546 FOOD INSPECTION ^ND ^N^ LYSIS. 

DISTINGUISHING BETWEEN BUTTER^ PROCESS BUTTER, AND 
OLEOMARGARINE. 

With the increased occurrence in the market of the commercial product 
known as " process " butter, especially in localities where its sale is 
restricted or regulated by law, it becomes incumbent on the analyst to 
distinguish it from the other products which it resembles. 

As a rule, the tests, chiefly physical, that are applied on the edible prod- 
uct as a whole (i.e., without separation of the curd, salt, etc.), such as the 
foam test, the milk test, the microscopical examination, and the appear- 
ance of the melted sample, distinguish broadly between pure fresh butter 
on the one hand, and oleomargarine on the other. In other words, al- 
though there are those skilled in making the above tests who claim to 
be and doubtless are able to note distinguishing features between oleo- 
margarine and process butter, yet these two products respond alike, 
though perhaps in varying degrees, to these tests, and are classed together 
as distinguished from pure butter. 

On the other hand, such tests as depend upon the refractometer, 
the Reichert number, and, indeed, all the so-called chemical constants, 
which are applied to the separated fat, freed from other substances, will 
serve to distinguish between oleomargarine and butter, whether "pro- 
cess" butter or otherwise, since the "processing" or "renovating" of 
butter does not change the character of its fat sufficiently to materially 
alter these constants. 

It is best, therefore, for purposes of routine preliminary separation 
to submit all samples to the "foam" test and to examine them by the 
butyro-refractometer.* These tests alone, which are very quickly and 
readily applied, will rarely fail to separate into the three classes, butter, pro- 
cess butter^ and oleomargarine, the products under examination, after which 
such confirmatory tests as are desired are made on adulterated samples. 

The Butyro-refractometer. — This instrument, as its name implies 
was primarily intended by Zeiss for the examination of butter, and, while 
its use has been extended for work with other fats and oils, its construc- 
tion is such as to show particularly a distinction between butter and 
oleomargarine by the appearance of the critical line of the fat. This 
mode of differentiation is due to the peculiar construction of the double 

* Out of the large number of samples of butter and oleomargarine examined on the 
butyro-refractometer in the author's laboratory during eight years, he has never found a 
single instance where the instrument failed to show the difference between the two products. 



EDIBLE OILS AND FATS. 547 

prism, which shows differences of dispersive power by different appear- 
ances of the critical line. The prisms are so constructed that the 
critical line of pure butter is colorless, while margarine and artificial 
butter, which have greater dispersive powers than natural butter, show 
a blue-colored critical line. But anomalies in the color, both with pure 
butter and mixtures, are more or less observable, which render it im- 
possible to draw a sharp line between adulterated and genuine butter. 
The appearance of a blue fringe may, however, be a useful factor in 
cases of suspected adulteration. 

The following particulars respecting the application of the refractom- 
eter for analysis of butter are contained in a paper of Dr. R. Wollny of 
Kiel,* who assisted in the construction of the instrument. The readings 
of the refractive indices of a large number of butter samples taken at 
25° C. by Dr. Wollny have been directly reduced to scale divisions and 
yield the following equivalents: 

Natural butter. . .(1.4590 — 1.4620): 49. 5 — 54.0 scale divisions 
Oleomargarine. . .(1.4650 — 1. 4700): 58. 6 — 66.4 " " 

Mixtures (artificial 
butter) (1.4620 — 1. 4690): 54. — 64. 8 " " 

Limit 0} Scale Reading for Pure Butter. — Whenever in the refracto- 
metric examination of butter at a temperature of 25° C. higher values 
than 54.0 are found for the critical line, these samples will, according 
to Wollny, by chemical analysis always be found to be adulterated; but 
with all samples in which the value for the position of the critical line 
does not reach 54.0 chemical analysis may be dispensed with, and the 
samples may be pronounced to be pure butter. Wollny suggests, as a 
means of removing all chances of adulterated butter escaping detection, 
that the above limit be placed still lower, and that all samples exhibiting 
values exceeding 52.5 (at a temperature of 25° C.) be set aside for chemi- 
cal analysis. 

In calculating the position of the critical line for other temperatures 
than 25° C. allow per 1° C. variation of temperature a mean value of 

* Dr. R. Wollny, Schlussbericht iiber die Butteruntersuchungsfrage, Milchwirthschaft- 
licher Verein, Korrespondenzblatt, No. 39, 1891, p. 15. 

Older papers on butter tests by refraction of light will be found in: Mueller, Rep. d. 
anal. Chemie, 1886, pp. 346, 366. Skalweit, Milchzeitung, 1886, 15, p. 462. Wollny, Ueber 
die Kunstbutterfrage, Leipzig, 1887, p. 50. 



548 



FOOD INSPECTION AND ANALYSIS. 



0.55 scale division.* The following table, which has been compiled 
in this manner, shows the values corresponding to various temperatures, 
each value being the upper limit of scale divisions admissible in pure 
butter: 



Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


45° 


41-5 


40° 


44-2 


35° 


47-0 


30° 


49.8 


44° 


42.0 


39° 


44-8 


34° 


47-5 


29° 


50-3 


43° 


42.6 


38° 


45-3 


^f 


48.1 


28° 


50.8 


42° 


43-1 


37° 


45-9 


32° 


48.6 


27° 


51-4 


41° 


43-7 


36° 


46.4 


31° 


49-2 


26"^ 


51-9 


40° 


44-2 


35° 


47.0 


30° 


49-8 


25° 


52.5 



If, therefore, at any temperature between 45° and 25° values be 
found for the critical line which are less than the values corresponding 
to the same temperature according to the table, the sample of butter may 
safely be pronounced to be natural, i.e., unadulterated butter. If the 
reading shows higher numbers for the critical line, the sample should be 
reserved for chemical analysis. 

Note. — Dr. Eichel of Metz has suggested that instead of comparing 
the scale divisions at the same temperature, the position of the critical 
line may be determined at the moment when the butter begins to set. 
In this case he gives fifty-four as the highest admissible number for the 
critical line of pure butter. 

No sharp distinction is apparent between pure and renovated butter 
on the refractometer. 

Special Thermometer for the Butyro-refractometer. — Instead of em- 
ploying the ordinary thermometer, as shown in Fig. 36, a special ther- 
mometer (Fig. loi) has been devised for work both with butter and 
with lard. This instrument has two scales, arranged side by side, one 
for butter and one for lard, each of which indicates at once the highest 
allowable reading for the pure fat, corresponding to the temperature 
at which the observation is made, which, however, need not be noted. 

If the scale reading of the instrument, as observed through the tele- 
scope, differs materially from the reading of the special thermometer, 
the fat under examination is undoubtedly adulterated, or, in the case 
of butter, a higher reading indicates oleomargarine. The special ther- 
mometer thus indicates the highest permissible number for pure butter. 



* With natural butter this number is, as a rule, somewhat less (0.53), with oleomargarine 
a little greater (0.56). 



EDIBLE OILS /IhlD FATS. 



549 




The Reichert or Reichert-Meissl Number * is by far the most impor- 
tant single determination in establishing proof of the character of the 
sample, whether butter or oleomargarine, for evidence in Q 

court, and in such cases this determination is indispensable. 
The result is conclusive, excepting in those rare instances 
where the admixture of foreign fat is so small as to cause 
the Reichert number to approximate that of pure butter. 
In common instances of creamery butter and commercial 
oleomargarine the Reichert number shows a very marked 
distinction (see table, p. 544). 

It is difficult to fix a minimum figure below which, in 
doubtful cases, a sample may be pronounced imjjure by 
reason of admixture with foreign fat. In general, how- 
ever, a Reichert number under 10 would be almost sure 
to show adulteration, though instances are on record where 
butter of known j)urity has shown a Reichert number even 
lower than this. It is in fact rare that pure butter has 
a Reichert number under 12. 

Stebbins t gives the maximum, minimum, and average 
of the Reichert number obtained by him on 317 samples 
of unadulterated butter, some of which were of low grade, j,^^^^^_gj^j 
as follows: Maximum, 18.2; Minimum, 11.2; Average, 14.7. Butyro-refrac- 

As a rule little difference is apparent between pure tomcter Ther- 

1 1 • -r. • 1 mometcr for 

and renovated samples as regards their Reichert Butter and 
number. Lard. 

Vieth has shown that the Reichert number of butter is generally a 
trifle lower after it becomes rancid. 

Specific Gravity. — Skalweit has shown that the specific gravity of 
butter and oleomargarine relative to each other varies \\'ith the temper- 
ature at which it is taken, the difference between the two growing less 
and less as the temperature increases above 35°. The greatest variation 
being at 35°, he recommends this temperature as the best at which to 
make the determination. 

The Foam Test, also known as the "boiling" or "spoon" test.f 
This, though originally intended as a household test, is in reality one of 

* The writer prefers to carry out this process on 2.5 grams of the butter fat, expressing 
thus the Reichert number, this being practically half the Reichert-Meissl number, which is 
based on the use of 5 grams. 

t Jour. Am. Chem. Soc, 21, 1899, p. 939. 

X Farmer's Bulletin, No. 131. 



550 . FOOD INSPECTION AND ANALYSIS. 

the very best laboratory methods of separating pure butter samples from 
renovated butter and oleomargarine. A small lump of the sample (from 
3 to 5 grams) is heated in a large spoon over a Bunsen flame, turned 
ver>' low, stirring constantly during the heating. Genuine butter, under 
these conditions, will boil quietly, but with the production of consider- 
able froth or foam, which will often swell up over the sides of the spoon, 
when, just after boiling, the latter is raised from the flame. Renovated 
butter or oleomargarine, under this treatment, will bump and sputter 
noisily like hot grease containing water, but will not foam.* Another 
point of difference is that on removing the spoon from the flame and 
observing the character of the curdy particles, in the case of genuine 
butter these particles of curd will be very small and finely divided in 
the melted fat, being indeed hardly perceptible, while with oleomargarine 
and renovated butter, the curd will gather in somewhat large masses or 
lumps. 

The test may be carried out in a test-tube if desired. 

The Waterhouse or Milk Test.f — This test is based on the assump- 
tion that butter fat, which is in itself exclusively the product of milk, 
will mingle intimately with the milk when added thereto in a melted 
condition and cooled therein, whereas oleomargarine, being foreign to 
milk fat, will, under like conditions, refuse to diffuse itself naturally 
in milk as a medium. 

About 50 cc. of well-mixed sweet milk are heated nearly to boiling 
in a beaker, and from 5 to 10 grams of the fat sample are added. The 
mixture is then stirred, preferably with a small wooden stick, until the 
fat is melted. The beaker is then placed in a dish of ice cold water, and 
the stirring continued till the fat reaches the solidifying-point, at which 
period, if the sample is oleomargarine, the fat can readily be collected 
by the stirrer into one lump or clot, but, if butter, it cannot be so collected, 
but remains in a granulated condition, distributed through the milk 
in small particles. It is not necessary to keep up the stirring through 
the entire term of cooling, but to begin stirring before the fat starts to 
solidify, which should require from ten to fifteen minutes after the mixture 
is placed in cold water. 

This test, if carefully carried out, shows a marked distinction between 
butter, whether pure or renovated, and oleomargarine. Under certain 
conditions, as when the cooling is too rapid, samples of renovated butter 

* A very slight foam is sometimes observable with occasional renovated samples, but 
nothing like the abundant amount produced by the genuine product. 
t Parsons, Jour. Am. Chem. Soc, 23, 1901, p. 200. 



EDIBLE OILS AND FATS. 55 1 

fat will sometimes show a slight tendency to clot together as in the case 
of oleomargarine, but to no such extent as the latter. 

The author's experience with this test has shown it to be \Qvy reliable 
not only in identifying oleomargarine from butter, but in nearly every 
case renovated butter can be distinguished from genuine. As a rule, 
genuine butter fat, even after cooling to the solidifying-point, shows the 
greatest tendency to emulsionize with the milk when stirred, without 
adhering to the wooden rod, and is slow to come to the surface when 
the stirring is stopped. Renovated butter fat, when stirred in the cold 
milk, almost instantly gathers in a film on the surface of the milk when 
the stirring is stopped, without emulsionizing. It does not clot together 
like oleomargarine, but it tends to adhere to the wooden rod. 

Patrick * recommends the use of skimmed or partially skimmed 
milk, and heats to the boiling-point after the fat has been introduced 
into the hot milk. 

Examination of the Curd. — The curd of genuine butter is made up 
largely of such of the milk proteins as are insoluble in water and hence 
pass into the cream when separated. These proteins form a gelatinous 
mass in the butter, readily clotting together when the fat is melted. On 
the other hand, the curd of process butter, which is, as it were, artificially 
derived from the entire or skim milk used in its manufacture (in order 
to replace the natural curd which has been removed in the "purifying" 
process), differs from the proteins of cream in that it is granular and 
flaky, consisting chiefly of coagulated casein. Hence the distinction 
noted as to the appearance of the curd in the foam test. 

For the same reason, if beakers containing pure and renovated butter 
are melted on the water-bath, the curd of the pure sample will settle at 
once, or in a very few minutes, to the bottom after melting, leaving a 
comparatively clear supernatant fat. The renovated sample will nearly 
always fail to settle out clear, even after standing on the water-bath for 
half an hour or more, but will still be cloudy throughout the mass, due 
to particles of non-cohesive, floating curd. 

In the case of oleomargarine, the curd of which is composed partly 
of pure butter curd (from cream proteins) and partly of the proteins 
of the milk with which it is churned, the cloudiness of the fat on melting 
depends on the relative proportion of milk proteins, and in general is not 
especially characteristic. 

* Farmer's Bulletin, Xo. 131. 



552 FOOD INSPECTION AND ANALYSIS. 

Identification of the Source of the Card.* — Half fill a small beaker 
with the sample and melt on the water-bath. Decant as much as possible 
of the fat and pour the rest, consisting largely of the water, salt, and 
curd, upon a wet filter. Acidify the filtrate, which contains the salt 
and soluble proteins, with acetic acid and boil. If the sample is pure 
butter, only a slight milkiness is found, indicating absence of albumins, 
whereas, in the case of process butter, a white, flocculent albuminous 
precipitate is produced. 

Apply to the filtrate also Liebermann's test for albumin; i.e., add 
strong hydrochloric acid. If a violet coloration is produced, the sample 
is presumably "process" butter. 

Microscopical Examination of Butter. — Considerable information may 
in general be gained by an examination of the sample under ordinary 
light and with a rather low power, say from 120 to 150 diameters. For 
examination in this way a bit of the sample on the edge of a knife blade 
is placed on the glass slide, and simply pressed lightly into a thin film 
by the cover-glass. A very characteristic difference between genuine 
and renovated butter is at once seen in the relative opacity of the fields. 
The fat film, in the case of fresh, pure butter, is much more transparent 
than that of the renovated. Again, the curd is so finely divided through- 
out the mass of genuine butter fat that the field is much more even than 
that of the renovated, wherein often large and opaque patches of curd 
are frequently distributed throughout the field. 

When a renovated butter sample, mounted as above, is viewed hy 
reflected light, for which purpose the microscope mirror is turned so as 
not to transmit light through the instrument, one sees a very dark and 
scarcely perceptible field; but the opaque patches of curd above referred 
to are strikingly apparent as white masses against a dark background. 

With Polarized Light. — It has already been stated that the micro- 
scope is useful in showing whether or not a fat has been melted, the 
crystalline structure of the fat once melted and afterward cooled being 
rendered apparent, especially when viewed by polarized light. This 
fact has long been known and put to practical use in the identification 
microscopically of butter and oleomargarine. f 

When viewed by polarized light between crossed Nicols under a 
low magnification, pure butter not previously melted should show no 

* Hess and Doolittle, Jour. Am. Chem. Soc, 22, 1900, p. 151. 
t Hummel, ibid., 22, p. 327; Crampton, loc. cit., supra, p. 703. 



EDIBLE OILS AND F/I'rs. 553 

crystalline structure, being uniformly bright throughout, and, if the 
selenite plate be used, should present an evenly colored field, entirely 
devoid of fat crystals. On the other hand, with process butter or oleo- 
margarine, both of v^hich have been melted and subsequently cooled^ 
the crystalline structure should be marked, showing with polarized light 
a more or less mottled appearance, and a play of colors with the seleni.e. 

Various conditions enter in to affect the reliability of the polarized light 
test. It is nearly always possible in cold weather to observe these dis- 
tinctions in practice, as above described, in a sharp and striking manner. 
Figs. 269, 270, and 271, PI. XXXVIII, show typical fields of the three 
products with crossed Nicols and selenite plate. The appearance of pure 
butter is perfectly blank, while oleomargarine presents a much more 
mottled appearance than renovated butter. Such well-defined points 
of variation as are shown in Plate XXXVIII are not always to be seen 
in practice, even in the hands of an expert. Pure butter sometimes 
exhibits a somewhat mottled field, due to a slight crystallization at some 
period in its history. In the summer-time, for instance, when butter 
melts so easily at ordinary temperature, these distinctions between pure 
and adulterated samples as shown by polarized light are by no means 
as satisfactory as in the winter. 

Great care should be taken on this account, on the part of the col- 
lector of samples as well as the analyst, to keep the sample from melting 
under ordinary conditions before it is examined. 

Hess and Doolittle's Method of Examining the Curd.* — A convenient 
portion of the sample of suspected butter is melted in a beaker, as much 
of the fat as possible is decanted off, and the remaining curd, washed 
free from fat with ether, is poured out on a glass plate and dried. A 
sample of pure butter is treated in like manner by way of comparison- 
When examined under a very low magnification of from 3 to 6 diameters, 
the curd from the pure sample will be seen to be non-granular 
and amorphous in appearance, while, in the case of renovated butter, 
the curd will appear very coarse grained and mottled. 

Zega's Test for Oleomargarine.t— A portion of the filtered fat is 
poured into a test-tube and kept for two minutes in a boiling water-bath. 
1 cc. of this fat is then measured with a hot pipette into a 50-cc. tube con- 
taining 20 cc. of a mixture of 6 parts ether, 4 parts alcohol, and i part 

glacial acetic acid. The tube is stoppered, shaken well, and cooled in 

. . j 

* Jour. Am. Chem. Soc, 22, 1900, p. 151. 

t Chem. Zeit., 1899, 23, 312; Abs. Analyst, 24, p. 206. 



554 FOOD INSPECTION AND ANALYSIS. 

water at 15° to 18° C. In the case of pure butter fat, the solution remains 
clear for some time, a slight deposit being apparent only after standing 
an hour or more. With oleomargarine, a deposit is evident in a very 
short time, and in ten minutes a heavy precipitate comes down. With 
10% of oleomargarine in butter, a separation occurs in about fifteen 
minutes. Wlien a few solid particles have separated out, they are with- 
drawn and examined under the microscope. With genuine butter, long 
narrow rods appear, sometimes pointed at the ends, often bent, and grouped 
as a rule centrally in star-shaped bundles. Oleomargarine presents an 
appearance of bundles of fine needles, closely packed to form masses 
frequently resembling sheaves and dumb bells in shape. 

Identification of Various Oils and Fats. — Cottonseed oil may be 
recognized, if present in butter or its substitutes, by the Halphen test, 
and sesame oil by the Baudouin test. Peanut oil is tested for by the 
Bellier or Renard test. 

Cocoanut oil is sometimes said to be present in butter substitutes. 
It has a higher Reichert number than most adulterants, and hence a 
larger admixture of this than of other foreign fats could be used, without 
lowering the Reichert number of the whole below the allowable limits 
of pure butter. Its presence would, however, be rendered apparent by the 
low iodine and refractometer numbers and the high Polenske number. 

LARD. 

Nature and Composition. — Lard is the fat of hogs, separated by heat 
from the scraps or containing tissues. The choicest or highest grade of 
lard is known as leaf lard, and is derived from the fat which surrounds 
the kidneys. A comparatively small part of the lard of commerce is, 
however, strictly speaking, pure leaf lard. Most of it is derived from 
the whole fat of the animal by rendering, by the aid of steam under 
pressure, either in open kettle or in closed tanks, the former being used 
more often for rendering lard on a small scale, and the latter being the 
most common commercial method. 

Next to the leaf, the fat from the hog's back is considered the best 
in quality, after which is graded, in the order named, the fat from the 
head, the region of the heart, and the small intestines, the last two grades 
constituting what is commonly known as "trimmings." 

Good lard is white and granular, having the consistency of salve. It 
has an agreeable, characteristic odor and taste. 

The leaf or kidney fat furnishes also the source of the so-called neutral 
lard, already mentioned as an ingredient of oleomargarine. The leaf, 



EDIBLE OILS AND FATS. 



555 



being first chilled and finely ground, is placed in the kettle and ren- 
dered at a temperature of from 40° to 50° C, at which heat only a portion 
of the lard separates. This portion is, while melted, washed with water 
containing salt or dilute acid, and forms the neutral lard, a product 
almost entirely free from odor. The remainder of the leaf is then trans- 
ferred to the closed tank and subjected for some hours to steam under 
pressure at a temperature of 230° to 290° F., the resulting lard being 
graded as pure leaf lard. 

The composition of the mixed fatty acids of lard is thus calculated 
by Twitchell: 

Linoleic acid 10. 06% 

Oleic acid 49 . 39% 

Solid acids (by difference), stearic and palmitic .. 48.55% 

Lewkowitsch * gives the following constants for American lards made 
from fat from different parts of the animal : 





Specific 

Gravity 

at 100° C. 

(Water at 

iS°C. = i.) 


Iodine 
Value. 


Maumen^ 

Number at 

40° c. 


Melting-point, Bense- 
mann'st Method. 


Refractive 
Index. 


Fat from 


Temp. C. 

of Incipient 

Fusion. 


Melted to 
a Clear 
Drop. 


Butyro- 

refractom- 

eter at 

40° c. 


Head 


0.8637 
0.8629 
0.8631 
O.8611 
0.8621 
0.8616 
0.8637 
0.8615 
0.8700 
0.8589 
0.8641 
0.8615 
0.8628 


66.2 
66.6 

65.0 
61.5 
65.0 
65.1 
62.2 

59-0 
63.0 
68.8 
68.4 
66.6 
68.3 


?>3 
32 
34 
37 
35 
38 

30 
38 


24 
24 
24 
28.5 

28-5 

31-5 

26 

29 

28.5 

24 

26 

26 

26 


44-8 
44.8 
45 -o 
48.5 
48.5 
46 

45 
44 

44-5 
40 

45 
44 
44.5 


52.6 

52-5 
52.0 

52-4 
51-8 

51-9 
51-4 

50.2 
52.0 
44-8 
51-9 
51-9 
53-0 


Back 


Leaf 


Foot 


Ham 




Ham (German) 


0.8597 


55-0 


30 


32 


46 


49.2 



Lard Oil. — This oil is obtained by subjecting lard contained in woolen 
bags to hydraulic pressure in the cold. The lard oil (chiefly olein) 
thus expressed constitutes nearly 60% of the whole, and the residue 
is known as lard stearin. 

Lard oil is a thin fluid, pale yellow in color, and with varying specific 

*Oils, Fats, and Waxes, 1904, p. 781. 

t Bensemann distinguishes between the temperature at which the fat begins to Hquefy 
and that at which it becomes completely transparent. 



556 FOOD INSPECTION AND /IN A LYSIS. 

gravity, due to varying conditions of pressure and temperature. It has 
a pleasant, though somewhat bland taste, and is used to some extent as 
an edible oil. It is used in France as an adulterant of olive oil, and 
with the Maumene, elaidin, and nitric acid tests, it behaves much like 
olive oil. 

According to the U. S. Pharmacopoeia, the specific gravity of lard oil 
should be from 0.910 to 0.920 at 15° C. 

At a temperature a little below 10° C. it should form a semi-solid 
white mass. 

When it is brought in contact with concentrated sulphuric acid, a 
dark reddish-brown color should instantly be produced. 

Lard oil should not respond to the Bechi test for cottonseed oil. 

If 5 cc. of the oil, contained in a small flask, be mixed with a solution 
of 2 grams of potassium hydroxide in 2 cc. of water, then 5 cc. of alcohol 
added, and the mixture heated for about live minutes on a water-bath 
with occasional agitation, a perfectly clear and complete solution should 
be formed, which, on dilution with water tathe volume of 50 cc, should 
form a transparent, light-yellow liquid, without the separation of an 
oily layer (absence of appreciable quantities of paraffin oils). 

Adulterants of lard oil are cottonseed and corn oils. 

Compound Lard. — The article so extensively made and sold under 
this name is a mixture consisting usually of lard stearin, beef stearin, 
and cottonseed oil. Sometimes no lard whatever is present, but only 
a mixture of beef and cottonseed stearins. 

Lard stearin is the residue left in the cloths after the lard oil has been 
removed by pressure (p. 555). 

Beef stearin is, similarly, the residue from which oleo oil has been 
expressed (p. 541). The cottonseed oil used is highly refined, and finally 
decolorized by mixing with fullers' earth and filtering. 

U. S. Standards. — Standard Lard and Standard Leaf Lard are lard and 
leaf lard respectively, free from rancidity, containing not more than 1% 
of substances other than fatty acids, not fat, necessarily incorporated 
therewith in the process of rendering, and standard leaf lard has an iodine 
number not greater than 60. 

Adulteration of Lard. — The mixture known as "compound lard'^ 
is quite commonly fraudulently sold for pure lard. Indeed, the adul- 
terants of lard usually met with are cottonseed oil or stearin and beef 
stearin. Other oils said to have been used as adulterants are peanut, 
sesame, corn, and cocoanut. Formerly water was incorporated into 



EDIBLE OILS AND FATS. 557 

the fat to such an extent as to materially cheapen it, but this sophistica- 
tion is now rare. ^Moisture is determined as in the case of butter. 

The Butyro-refractometer Reading. — The refracting degree of cotton- 
seed oil on the butyro-refractometer is about 8.9 in excess of the standard 
refraction of lard, while that of beef tallow is about 3.8 less than the 
standard. If, therefore, the refractometer reading is unusually low, the 
presence of beef stearin is to be suspected; if unusually high, cottonseed 
oil should be looked for. A mixture of the two adulterants with pure 
ly.rd such as is found in "compound lard," may sometimes, though not 
often, be found to give refractometric readings within the limits of pure 
lard. 

Detection of Foreign Oils. — Cottonseed oil is best detected by the 
Halphen test. A very slight color reaction should not be taken as proof 
positive of the admixture of cottonseed oil, since it has been found that 
the fat of hogs fed on cottonseed meal gives a slight reaction with both 
the Bechi and the Halphen tests. Sesame and peanut oils are detected 
by their special tests. Corn oil is indicated by the abnormally high 
refractometric reading and iodine number, Qocoanut oil by the high 
Rcichert number, the high saponification equivalent, and especially the 
high Polenske number. 

Beef stearin is difficult to identify chemically, but is usually distin- 
guished by a microscopical examination of the fat after cr}'Stallization 
as follows : 

The Microscopical Examination of Lard. — From 2 to 5 grams of 
the fat are dissolved in 10 to 20 cc. of ether * in a test-tube, and the solu- 
tion allowed to stand 12 hours or over night at about 20° C, the test- 
tube being loosely stoppered with cotton. The cr)'stals obtained vary 
considerably with, the condition of heat, amount of solvent, rate of cr}'^s- 
tallization, etc., so that the operator had best vary these conditions till 
he is satisfied that the best possible results have been obtained. It is 
often advantageous to separate the crj'stals first obtained by filtration 
from the mother liquor, and to redissolve in ether and recr}'stallize in 
a second test-tube. The crj'stals formed at the bottom of the test-tube 
are, for the purpose of thus purifying, separated from the mother liquor 
by filtration through a small filter, and the precipitate washed several 
times with ether. The washing wdth ether should not be continued 
so long that the cr}^stals are perfectly freed from mother liquor and olein, 
for in this case they are so dr)- and pulverulent as to require a mountant 
when on the slide for microscopical examination. The writer prefers 

* Some analysts get better results with a mixture of ether and alcohol. 



558 FOOD INSPECTION AND ANALYSIS. 

to have them sHghtly oleaginous, so that when applied to the slide nO' 
mountant need be used. In this case the crystals seem to stand out in 
wider contrast to the background than when cottonseed oil, the usual 
medium, is used. 

If the crystals are, however, in a pulverulent condition, a drop of 
alcohol can be used as a mountant, or oil, as preferred. Mounted under 
a cover-glass they are examined under various powers of the microscope. 

Figs. 272 and 273, PL XXXIX, show the typical appearance of 
pure lard stearin from a leaf lard of known purity, and Figs. 276, 277^ 
and 278 illustrate beef stearin. These figures show distinctive crystal- 
lization of each form under the best conditions. The lard stearin 
crystals when thus obtained are flat rhomboidal plates cut off obhquely 
at one end, and are grouped irregularly, as if thrown carelessly together. 
The beef stearin crystals, on the other hand, are cylindrical rods or 
needles, often curved, with sharp ends, and are arranged as shown in fan- 
shaped clusters. Conditions of crystallization are frequently such as not to 
show the sharp distinctions noted above. Both forms of crystals are at 
times apt to gather in -clusters that at first sight appear somewhat 
similar, and are often misleading as to their true character. It is found 
almost invariably that the beef stearin crystals gather in clusters, radiat- 
ing from a common center or point, often with a peculiar twisted appear- 
ance, breaking up into little fans. Lard crystals, it is true, do not always 
lie flat in irregular groups as shown in Fig. 272, but, as in Fig. 274, form 
clusters that, unless studied carefully, might at first sight be considered 
as identical with the fan shapes of the beef stearin already described. 
It will be seen, however, that if the best possible conditions are attained, 
the crystals of lard, instead of radiating from a point, are arranged more 
like feathers or alternate leaves on a branch, each crystal being given forth 
from another close at hand. Moreover, the lard crystals are themselves 
straight and not curved, the apparent curve in the appearance of the 
clusters being, on careful examination, especially under high power, 
seen to be chiefly due to several of these straight crystals arranged at 
angles to each other. 

Even when the highest powers of the microscope are applied to the 
beef stearin crystals, they will always appear as cylindrical, sharp- 
pointed rods, some straight, others curved; while with the lard crystals 
they should be capable of showing the thin, flat, oblique-ended structure 
when examined with higher powers, even when they are arranged in the 
feathery clusters, the apparently pointed ends of some of the cr>'stals 



EDIBLE OILS AND FATS. 



55^ 



being due to the fact that the plates are viewed edgewise. This is apparent 
in Fig. 275, in which the crystals are magnified to 480 diameters. 

According to Belfield, who was one of the earliest to employ the micro- 
scope for identification of foreign fat in lard, it is possible to detect well- 
defined crystals of both lard and beef stearin in mixtures crj^stallized 
out in the above manner from ether. Later investigators, however, find 
difficulty in getting both kinds of crystals in the final deposit, it being 
the more common experience that the character of the final crystals from 
a mixture of the two fats more often tends to one or the other forms of 
crystallization. Repeated crystallizations may change the character of 
the crystals and a number of such crytallizations should therefore be 
made before final judgment is passed. 

The Iodine Number (p. 487). — This test is generally prefigured by 
the refractometer. Cottonseed oil will absorb about 108% of its weight 
of iodine, while beef fat will absorb about 37%. 

ANALYSES OF SAMPLES ILLUSTRATING TYPES OF LARD, LARD SUBSTI- 
TUTES, AND MIXTURES. 



A 
B 
C 
D 
E 
F 
G 
H 
I 

J 
K 
L 

M 

N 



Nitric Acid Test. 



Slight color. 
Red 

Slight color 



Very slight color 
Deep-brown red 

Red 



Very slight color 
Deep brown 



Red. 



Crystallization. 



Lard stearin 



Beef stearin 
Few small 

bunches 
Lard stearin 

Lard and 

beef stearin 
Lard stearin 



Lard and 
beef stearin 



Bechi Reac- 
tion. 



None 



Deep color 
<( ti 

None 

Deep color 

i' tt 
< <( 



Butyro-refrac- 
tometer. 






42-5 
42 

41-5 

43 

41-3 

42 

42 

50 
42 

43 
43 
43-5 

43-7 

43-5 



Pil 



49-7 

50 

50.1 

50 

51 

50-5 

49-7 

41.2 

58-7 
50-5 
48.5 
51 

50.1 
49.1 



.SES 



-fo.i 

4-0.2 
-l-o.o 

-t-0.6 
-1-0.8 
-f 0.7 

— O. I 

-3-8 
-^8.9 

+ 1-3 

-0.7 

4-1. 1 

+ 1-3 
+ 0-3 



58.1 
59-9 
58.7 
63-7 
64.6 
64.8 
56-4 
37-3 



69-5 

55-2 

71.4 

66.7 
54-7 



Conclusion. 



Lard 



Leaf lard 
Beef tallow 
Cottonseed oil 

Lard and cotton- 
seed oil 

Lard and beef 
tallow 

Lard and cotton- 
seed oil 
Ditto 

Lard, beef tallow, 
and cottonseed 
oil 



Notes on the Above Table. — It will in general be noted that adultera- 
tion of lard with cottonseed oil alone is indicated by an abnormally high 



56o FOOD INSPECTION AND /IN A LYSIS. 

refractometer number, while the presence of tallow will result in an 
abnormally low refraction. But both adulterants may be present and 
a normal refraction result. In such a case the positive detection of one 
of them, such as the cottonseed oil by the Bechi or Halphen test, will 
indirectly show the presence of the other (tallow), and this indirect proof 
will be confirmed by crystallization. 

Samples A, B, and C give reactions corresponding to normal, pure 
lard. D, E, and F show somewhat high refractometer and iodine 
numbers, but give no direct reaction for cottonseed oil by the Bechi test. 
G, although showing low iodine and refractometer numbers, gives no 
evidence of the presence of tallow by crj-^stallization. In fact, the cr}'s- 
tals from this sample proved under all circumstances to be most clearly 
typical of pure lard, broad and flat plates with obliquely cut ends. 

This sample was, in fact, pure leaf lard. It is generally true that a 
stiff, strictly pure leaf lard, which both by its consistency and by its low 
iodine and refractometer numbers might suggest the presence of beef fat, 
shows on crystallization much more definitely characteristic lard stearin 
than does a whole-hog lard, whose iodine and refractometer numbers 
are more nearly the normal standard. 

In distinction from such leaf lard, a sample which may have a similar 
consistency and iodine and refractometer numbers, but which is composed 
of a whole-hog lard of a comparatively high iodine number, together 
with beef fat, gives unmistakable proof of its adulteration by its crystal- 
lization. 

Effects of Feeding Hogs on Oil Cakes. — Fulmer,* Emmett and 
Grindleyt and other investigators have found that feeding cottonseed 
meal to hogs causes the lard from these hogs to give a color with the 
Halphen test, but TolmaD,| Farnsteiner§ and Polenske|| have shown 
that the lard does not contain phytosterol when examined by Bomer's 
phytosterol acetate method. 

Lard from hogs fed on sesame cake has been shown to respond to the 
Baudouin test, but not to the phytosterol acetate test. 

* Jour. Am. Chem. Soc, 26, 1904, p. 837. 

t Ibid., 27, 1905, p. 263. 

t Ibid., p. 589. 

§ Zeits. Unters. Nahr. Genuss., 11, 1906, p. i. 

II Arb. Kaiserl. Gesundheitsamt., 22, 1905, p. 568. 



EDIBLE OILS AND FATS. $bl 

REFERENCES ON EDIBLE OILS AND FATS. 

Andes, L. E. Animal Fats and Oils. 

Vegetable Fats and Oils. London, 1897, 

Arnold, W. Beitriige zur Analyse der Speisefette. Zeits. Unters. Nahr. Genuss., 

10, 1905, p. 201. 

Beitrage zum Ausbau der Chemie der Speisefette. Ibid., 14, 1907, p. 147. 

Benedikt, R. Analyse der Fette und Wachsarten. Berlin, 1892. 

Beau\7SAGE, G. Les Matieres Gras. Paris, 1891. 

Bock AIRY, L. Huiles Comestibles. Analyse des Matieres Alimentaires (Girard et 

Dupre), p. 401. Paris, 1894. 
Bornemann, G. Die Fetten Oele des Pflanzen und Thierreiches. Weimar, 1889. 
Brannt, W. T. Animal and Vegetable Fats and Oils. Phila., 1888. 
Cannizzaro, S., and Fabris, G. Reliability of Tests for Determining the Purity of 

Olive Oil. Rome, 1891. 
Dunlap, F. L. The Preparation of Aldehyde-Free Ethyl Alcohol for Use in Oil and 

Fat Analysis. Jour. Am. Chem. Soc, 28, 1906, p. 395. 
Farnsteiner, K. Vorschlage des Ausschusses zur Abanderung des Abschnittes 

" Speisefette und Oele " der Vereinbarungen. Zelts. Unters. Nahr. Genuss., 

10, 1905, p. 51. 
Fischer, K., und Peyan, H. Beitrage zur Kenntnis des Baumwollsamenoles und der 

Halphen'schen Reaktion. Zeits. Unters. Nahr. Genuss., 9, 1905, p. 81. 
Gill, A. A Short Handbook of Oil Analysis. Phila., 1900. 
Hanus, J., und Stekl, L. Die Aethylesterzahl, eine neue Konstante Zum Nachweise 

Cocosfettes. Zeits. Unters. Nahr. Genuss., 15, 1908, p. 577. 
Hehner, O., and Mitchell, C. A. On the Determination of Stearic Acid in Fats. 

Analyst, 21, 316. 
Hopkins, E. H. The Oil Chemists' Handbook. New York, 1901. 
Hunt, F. W. A Comparison of Methods used to Determine the Iodine Values of Oils. 

Jour. Soc. Chem. Ind., 1902, 454. 
Lewkowitsch, J. Chemical Analysis of Oils, Fats, and Waxes. 3d ed. London, 

1904. 

■ Laboratory Companion to Fats and Oils Industries. London, 1901. 

Lichtenberg, C. Die Fettwaaren und fetten Oele. Weimar, 1880. 

Lythgoe, H. C. Readings on the Zei.ss Butyro-refractometer of Edible Oils and Fats. 

Technology Quarterly, 16, 1903, p. 222. 
Macfarlane, T. Olive Oil. Can. Inl. Rev. Dept., Bui., 67. 
M.areille, R. Die Bildung der freien Saure und das Ranzigwerden der Olivenole 

Seifensieder Ztg., 31, 1904, pp. 630, 656, 671, 691. 
McPherson, W., and Ruth, W. A. Corn Oil — Its Possibilities as an Adulterant in 

Lard and its Detection. Jour. Am. Chem. Soc, 29, 1907, p. 921. 
PoLENSKE, E. Beitrage zur Untersuchung von Schweineschmalz und Butter. Arb. 

Kaiserl. Gesundh. Amt., 22, 1905, p. 557. 
Rae & Co. Prima Arborum. The Olive Tree and its Fruit. New York, 1887. 
Schadler, C. Die Untersuchung der Fette, Oele, Wachsarten, etc. Leipzig, 1889. 
Die Technologie der Fette und Oele des Pflanzen und Thierreichs. Leipzig, 1892. 



^62 POOD INSPECTION AND ANALYSIS. 

Thalmann, F. Die Fette und Oele. Leipzig, 1881. 

ToLMAN, L. M. Edible Oils and Fats. U. S. Dept. of Agric, Bur.of Chem., Bui. 65, 

p. 20. 
Report of Cooperative Work on the Dalican Titer Test. U. S. Dept. Agric, Bur. 

Chem., Bui. 81, p. 65. 

Report on Fats and Oils. Ibid. Bui. 90, p. 69. 

ToLMAN, L. M., and Munson, L. S. Use of the Bechi Test in Olive Oils. Jour. Am. 

Chem., Soc. 24, 1902, 397. 

Refractive Indices of Salad Oils. Jour. Am. Chem. Soc, 24, 1902, 754. 

Iodine Absorption of Oils and Fats. Jour. Am. Chem. Soc, 1903, 244. 

Olive Oil and its Substitutes. U. S. Dept. of Agric, Bur. of Chem., Bui. 77. 

Villon, A. M. Les Corps Gras. Paris, 1890. 

VuLTE, H. T., and Gibson, H. W. Nature and Properties of Corn Oil. Jour. Am. 

Chem. Soc, 23, 1901. p. i. 
Wright, A. C. Analysis of Oils and Allied Substances. New York, 1903. 
Wright, C. R. A. Animal and Vegetable Fixed Oils, Fats, Butters, and Waxes. 

London, 1894. 
California Exp. Sta. Buls. 104, 123, 129, 137, et al., on California Olives and Olive 

Oils. 
California Exp. Sta. An. Reports, 1892 et seq. 
Connecticut Exp. Sta. An. Report, 1897, p. 44. 

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Alvori), H. E. Composition and Characteristics of Butter. Penn. Dept of Agric. 

An. Rep., 1898, p. 558. 
BocK.'URY, L. Beurre, Analyse des Matieres Alimentaires (Girard et Dupre), p. 351. 

Paris, 1894. 
Brackett, E. G. Healthfulness of Oleomargarine as an Article of Food. Mass. State 

Board of Health An. Rep., 1887, p. 248. 
Browne, C. A., Jr. A Contribution to the Chemistry of Butter Fat. Jour. Am. 

Chem. Soc, 21, 1899, pp. 612, 807, 975. 
Cochran, C. B. Butter and Butter Adulterants. Jour. Frankl. Inst., 147, 1899, p. 85. 

Butter and Butter Adulterants. Penn. Dept. of Agric. An. Rep., 1898, p. 616. 

Detection of Foreign Fats in Butter. Jour. Am. Chem. Soc, 19, p. 796. 

CoRNW.ALL, H. B. E.xamination of Butter Colors. Chem. News, 55, p. 49. 
Crampton, C. A. The Composition of Process or Renovated Butter. Jour. Am. 

Chem. Soc, 25, 1903, p. 358. 
Fritzsche, M. Die bisherigen Erfahrungen und Urteile iiber die Poienske'sche Zahl 

und ein Beitrag zur Kenntnis derselben bei hollandischer Versandbutter. 

Zeits. Unters. Nahr. Genuss., 15, 1908, p. 193. 
Geissler, J. F. A Delicate Test for Color in Butter. Jour. Am. Chem. Soc, 20, 

p. no. 
Genth, F. a. The Necessity for a Butter Standard. Penn. Dept. of Agric. An. Rep., 

1897, p. 549- 
Girard et Brevans. Le Margarin et le Beurre Artificiel. Paris, 1889. 



EDIBLE OILS ^ND FATS. 563 

Gray, C. E. A Rapid Method for the Determination of Water in Butter. U. S. 

Dept. Agric, Bur. Animal Ind., Circ. Xo. 100. 
Harris, F. W. The Estimation of Cocoanut Oil in Butter Fat. Analyst, 31, 1906, 

P- 353- 
Hehner, O., and Angell, A. Butter, its Analysis and Adulteration, London, 1877. 
Hess, W. H. and Doolittle, R E. Methods for the Detection of Process or Reno- 
vated Butter. Jour. Am. Chem. Soc, 22, 1900, p. 150. 
HT3IMEL, J A. Examination of Brown and Taylor's Official Method of Identif)'ing 

Butter. Jour. Am. Chem. Soc. 22, 1900, pp. 327, 703 
Lang, V. Fabrikation von Kunstbutter. Leipzig, 1885. 
Low, A. W. Testing for a Yellow Azo-Color in Fats. Jour. Am. Chem. Soc, 20 

1898, p. 889. 
Macfarlane. T. Butter. Can. Inl. Rev. Dept., Bui. 16. 
Martin, E. W. Detection of Artificial Coloring Matter in Butter, Oleomargarine, 

etc Analyst, 12, 1887, p. 70. 
Moore, R. W. A Test for Carrot Color in Butter. Analyst, 11, 1886, p. 163. 
Patrick G. F. The Rapid Determination of Water in Butter. Jour Am. Chem. 

Soc, 28, 1906, p. 1611; 29, 1907, p. 1126. 
Polenske, E. Eine neue Methode zur Bestimmung des Kokosfettes in der Butter. 

Zeits. Unters. Xahr. Genuss., 7, 1904, p. 273. 
VON Ryn, J. J. L. Composition of Dutch Butter. London, 1902. 
DE ScH^VEiNiTZ and Emery. L'se of the Calorimeter in Detecting Adulterations of 

Butter. Jour. Am. Chem. Soc, 18, 1896, p. 174. 
Sell, E. Ueber Kunstbutter, ihre Herstellung, etc. Berlin, 1886. 
Stebbins, J. H. On the Reichert Figure of Butter. 
Zane, A. J. General Analyse des Beurres. Paris, 1892. 
Farmer's Bulletin 12. Nostrums for Increasing the Yield of Butter. 
" " 57. Butter Making on the Farm. 

" " 92. Pasteurization in Butter Making. 

" "131. Household Tests for the Detection of Oleomargarine and 

Renovated Butter. 
Minnesota Exp. Sta. Bui. 74. Digestibility and Food Value of Butter. 
Xew York Exp. Sta. (Ithaca) Bui. 118. Butter Increasers. 
North Carolina Exp. Sta. Bui. 166. Butter, its Composition, Artificial Imitation, and 

Adulterants. 
Storrs, Conn. Exp. Sta nth An. Rep., page 85. Bacteriology in Butter Making. 



REFERENCES ON LARD. 

Cochran, C. B. Detection of Foreign Fats in Lard and Butter. 

CoNROY, M. Lard, its Adulteration with Cottonseed Oil and Detection Thereof. 

Analyst, 13, 203. 
Farnsteiner, K. Kendrich, K, .und Buttenberg, P. Zusammensetzung des Fettes 

von Stark mit olhaltigen Futtermitteln gefiitterten Schweinen. Zeits. Unters. 

Nahr. Genuss., 11, 1906, p. i. 



S(>\ /■()()/) INSI'liCriON ,-1NI) /IN. ^ LYSIS. 

FULMICR, E. Some Notes Conrcrninj^ If,'il[)hcn's 'F'cst for Cottonseed Oil. Jour. 

Am. Chcm. Soc, 24, 1902, p. 1149. 
On Reaclion.s of L.inl from ("olton.secfl Meal-fed Hog.s with Halphen'.s Reagent. 

11)1(1. 26, r(;04, J). H37. 
(ji,Ai>iiiN(;, T. S. Examination of l-ard for Adulteration. Analy.st, 14, 1889, |). 32. 

Micro.scopit Detection of Heef I'at in Lard. Jour. Am. Chem. Soc., 18, p. 189. 

IIkhnkk, C). On Helfield'-s Te.st for ikef Stearin in Larfl. Analyst, 27, 1902, \). 247. 
KoNic, J., iiiid S( ifi.iiKKEniKR, J. Ucbcr fien Einfluss des Futtcrfettes auf das Korpcr- 

fctl Ixi S(l)wein(!n mit l)e.sonderer lierljeksiehtigunj^ des Verbleibs des Phytos- 

tcriiis. Z(;its. (Jnt(;rs. Nahr. (/(;nuss., 15, 1908, p. 641. 
MACf'ARt.ANK, 'I". Lard. Canadian Fnl. R(rv. I)e|)t., liul. 7. 

Stock, W. V. K. On the Estimation of JJeef F-'at in Lard. Analy.st, 19, 1894, p. 2. 
Tennitj;, O. V. Determination of Solid Eats in Compound Lard. Jour. Am. Chem. 

Soc, 19, [897, p. 51 
Toi.MAN, L. M. FOxaminalion of F,;ird from (Cottonseed Mealfcd FFogs, by F'hytos- 

terol Acetate Mel hod of |{r)nner. Jour. Am. Chem. Soc,, 27, 1905, p. 589. 
Wr.ssf)N, F). F'',xamin;itioii of Lard for Fmpurities. Jour. Am. Chem. Soc., 17, 1895, 

l>- 72,^- 
Wii.i.v, II. VV. <.)ii;inlil;itivc I'lsl iirialion of Adidlcniuls in Lard. Analyst, 14, 1889, 

I'- 7,^ 
F.ard and L;ird Adnllcralions, IJ. S. F)c[)t. of Af^'ric, Div. of ("hem., FJul. 13, 

j.arl 4 
VViiciiiM'., !•'. F)clc(lion of (Cotlon.secd Sicarin in F.;ird. Analyst, 27, 1902, p. 247. 
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Ma.ss. State Floard of FFealth An. F<ep., 1895, j). 668. 



nrAPTisR xjv. 

SUGAR AND SACCIIAIUNF. rRODlKTS. 

Nature and Classification of Sugars. — Of all (lasses of food ma(r- 
rials the sugars from llicir f^rcal solubility arc the inosl readily available, 
and on this arrount arc very valuable as niilrients. As in Ihe natural 
processes of digcslion the starrhes and more difneultly digestible of tlio 
carbohydrates arc converted into sugar and thus rendered assinn'lable,' 
Ko by processes (juite analogous to those that take place In the alinienlaiy 
trad, the chemist converts these same carbohydrates into sugar as an 
end ])oint for ])urj)oses of dcfmiie determination. 

The sugars are eharaclerized by their sweet taste, their readv solu- 
bility in water, their ])ower to rotate the plane of ])olari/,ed light, and 
their insolubility in ether and absolute alcohol. 

'i'he sugars occurring commonly in food naturally divide themselves 
into two groups: First, the Saccharoses, or cane sugar group, ha\ing 
the composition CiJIv/),,, of which the most ])rominent members are 
sucrose, maltose, and lactose; and, second, th(; (ihicoses, or grape sugar 
group, expressed by the formula t'dir,./),,, which includes clcxtrosc, levulosc 
and galactose, besides other less common sugars. 

The members of both grou])s arc intimately related. Thus by the 
ordinary process of so-called inversion sucrose, or cane sugar, belonging to 
grou]) 1, is converted by the action of heat and dilute acid into two sugars, 
dextrose and levulosc, whi( h are members oi group 2, in accordance 
with the following reaction: 

Cane suKiir DcxtroHc LuvuIdsc 

The same formula expresses also the result that takes place when 
lactose, or milk sugar, is heated with dilute acids, breaking up into dextrose 
and galactose. 

565 



566 



FOOD INSPECTION AND ANALYSIS. 



Occurrence. — Sugars occur in roots, grasses, stems of plants, trunks 
of trees, leaves, and fruits, usually in the form of cane sugar, or sucrose, 
and of invert sugar (dextrose and levulose) mixed in varying propor- 
tions. 

The following table from Buignet * shows the kind and amount of 
sugars occurring in some of the common fruits : 



Apricots 

Pineapples 

English cherries. . 

Lemons 

Figs 

Strawberries 

Raspberries 

Gooseberries 

Oranges 

Peaches (green) . . 
Pears (Madeleine) 
Apples 

Prunes 

Grapes (hothouse) 
' ' green 



Cane Sugar. 



6. 



4.22 

.92 

-36 

5.28 

2.19 

5-24 
.00 
.00 



Reducing 
Sugar. 



2.74 

1.98 

10.00 

1.06 



S.42 
8.72 

5-45 

2-43 

17.26 

1.60 



Acid. 



.864 

•547 
.661 
.706 

•057 
•550 
.380 

•574 
• 44S 
.900 

•115 
.148 

•633 
.288 

•345 
■485 



CANE SUGAR, OR SUCROSE. 

Nature and Occurrence. — This, the most common of all the sugars, 
is nearly always understood by the unqualified term of sugar. It crys- 
tallizes in monoclinic prisms. Its specific gravity is 1.595. Its melting- 
point is about 160° C. Its specific rotary power [a]^ in solutions ha\'ing 
a concentration of from 10 to 20 grams in 100 cc. is, according to ToUens, 
66.48°. Sucrose is extremely soluble in water, which, when cold, will 
hold in solution twice its weight of the sugar. 

Cane sugar is ordinarily derived from four sources — the sugar beet, 
the sugar cane, the maple tree, and the sorghum plant. The first two 
sources supply the principal output of commercial cane sugar, about 
two-thirds of the sugar on the market being furnished, according to 
Wiley, by the sugar beet and one-third by the sugar cane. It should be 
understood that the product sucrose, or cane sugar, is chemically the same 
whether derived from either of the above sources and thoroughly refined. 

U. S. Standard Sugar is white sugar containing at least 99.5% of 
sucrose. 



* Ann. Chim. Phys., 59, 233. 



SUGAR AND SACCHARINE PRODUCTS. 



567 



The Sugar Cane (Saccharum officinarum) is cultivated principally in 
Louisiana and other southern states, in Cuba and the West Indies, and 
in the Hawaiian Islands. Its growth and cultivation form an industry 
in nearly all tropical countries. 

Allen * has compiled the following table showing the composition 
of the juice of the sugar cane from different localities: 



Locality and Kind 
of Cane. 


Water. 


Sugar. 


Woody 
Fiber. 


Salts. 


Authority. 


Martinique 


72.1 
72.0 
77.0 

65-9 
69.0 

76-73 
76.08 


18.0 
17-8 
12.0 
17.7 
20.0 

13-39 
14.28 


9-9 

9-8 

II. 

16.4 

10. 

9.07 

8.87 


0.4 

I.O 

-39 

•35 


Peligot 
Dupuy 


Guadaloupe 

Havana 


Cuba 




Mauritius 


leery 

Avequin 

Avequin 


Ribbon cane 

Tahiti 



The composition of raw cane sugar ash according to Monier is as 
follows : 

RAW CANE SUGAR ASH. 

Carbonate of calcium 49 .00 

" " potassium 16.50 

Sodium and potassium sulphate 16 .00 

Sodium chloride 9 .00 

Silica and alumina 9 - 50 



100.00 



Manufacture of Cane Sugar, — ^The process of manufacturing raw 
sugar from sugar cane is briefly as follows: The juice is first extracted 
from the canes by crushing in roll mills and is freed from nitrogenous 
bodies, organic acids, etc., by the process of dejecation, which consists 
in heating to coagulate the albumin, and nearly neutralizing with milk 
of lime, the impurities being removed as a scum. The juice is then 
subjected to evaporation and cr}'Stallization, the raw, or muscovado sugar, 
which contains from 87 to 91 per cent of sucrose, being separated from 
the molasses, which is the mother liquor, by draining or by centrifugal. 

Some of the best grade of muscovado, or raw sugar, is used as ' ' brown 
sugar" without further refining, and much of the molasses is used as a 
table syrup and for cooking, while the lower grades of molasses are used 
in the manufacture of rum. 

* Com. Org. Analysis, i, p. 315. 



5^5 



FOOD INSPECTION /IND JN^ LYSIS. 



The following table from Thorpe * shows the average composition 
of raw and refined sugar: 



Cane 
Sugar. 



Glucose'. 



Water. 



Organic 
Matter. 



Ash. 



RAW SUGAR. 

Good centrifugal 

Poor centrifugal 

Good muscovado. 

Poor muscovado 

Molasses sugar 

Jaggary sugar 

Manilla sugar 

Beet sugar, ist 

Beet sugar, 2d 



REFINED SUGAR. 

Granulated sugar 

White coffee sugar 

Yellow X C sugar 

Yellow sugar 

Barrel sugar , 



96.5 
92.0 
91.0 
82. c 
85.0 

75-0 
87.0 

95-0 
91.0 

99-8 
91.0 
87.0 
82.0 
40.0 



0-75 
2.50 
2.25 
7.00 
3.00 
11.00 

5-50 
0.00 
0.25 



0.20 
2.40 
4.50 
7.50 
2^.00 



1.50 
3.00 
5.00 
6.00 
S-oo 
8.00 
4.00 
2.00 
3.00 



0.00 

5-50 
6.00 
6.00 



0.85 

1-75 
1. 10 

3-50 
5.00 
4.00 
2.25 
1-75 
3-25 



0.00 
0.80 

1-50 

2.50 

10.00 



0.40 

0-75 
0.65 

1-50 
2.00 
2.00 
1-25 
1-25 
2.50 

0.00 
0.30 
1 .00 
2.00 

=; .00 



'The term "glucose" includes sugars which reduce Fehling's solution, but are not necessarily 
optically active. 

The following minimum and maximum figures are taken from analyses 
made by Babington f of twenty-two samples of brown sugar and thirty- 
one samples of molasses. 



BROWN SUGAR. 

Direct polarization 84 to 

Invert " -27 " 

Sucrose by Clerget 83 , 5 '* 

Reducing sugar 3 " 

Moisture 3.5 " 

Ash 0.8 " 

MOLASSES. 

Direct polarization 30 to 

Invert " -10 " 

Sucrose by Clerget 32 " 

Reducing sugar 13 " 

Moisture 29 " 

Ash 0.5 '' 

* Outlines of Industrial Chem., p. 383. 
t Can. Inl. Rev. Dept. Bui. 25. 



87 
29 

91.5 

6 
6 
3-0 



50 
— 21 

52 
24 

32 

4 



SUG^R AND SACCHARINE PRODUCTS. 



569 



The Sugar Beet {Beta vulgaris) is grown chiefly in France and Ger- 
many, and to a lesser extent in Holland and England. The successful 
growth of the sugar beet in the United States is confined mainly to Cali- 
fornia, Utah, and Nebraska, and the entire output of beet sugar in this 
countr}' is comparatively small. 

According to R. Hoffmann, sugar beets have about the following 
composition, three types bemg selected — first, those poor in sugar; second,, 
those having a medium sugar content, and third, those rich in sugar: 



COMPOSITION OF THE SUGAR BEET. 



First Type. 



Second Type. 



Third Type. 



Water 

Sugar 

Nitrogenous compounds 

Non -nitrogenous compounds 

Soluble 

Insoluble (cellulose) 

Ash 



69.20 
4.00 

1. 00 

4-13 

1. 01 
0.66 



83.20 
9.42 
1.64 

3-34 
1.50 
o.go 



75.20 

li^.OO 



4.23 

2.07 

1.30 



The following is the mean composition of ten samples of CalifomicL 
sugar beet : * 

Per cent juice extracted 61 .38 

Specific gravity i .062 to i .075 

Per cent of reducing sugar 0.91 

Per cent of sucrose 14-38 

Total solids calculated 16.58 

Total solids weighed 1 7 . 20 

Per cent of ash o . 994 

The composition of beet sugar ash according to Monier is as follows r 

RAW BEET SUGAR ASH. 

Carbonates of potassium and sodium 82 . 20 

Carbonate of calcium 6 . 70 

Potassium and sodium sulphate and sodium chloride. ... 11 .10 * 



100.00 



Manufacture of Beet Sugar. — In making raw sugar from sugar beets- 
the latter are first washed and sliced by machinery and the juice extracted 

* U. S. Dept. of Agric, Div. of Chem., Bui. 27, p. ao2. 



570 FOOD INSPECTION AND ANALYSIS. 

by diffusion or digestion with warm water. The juice is then clarified 
or defecated in much the same manner as that from the sugar cane, after 
which it is usually bleached* with sulphur dioxide. 

The subsequent evaporation and crystallization are carried out usu- 
ally in vacuum pans, and the sugar separated out by centrifugals. 

Beet sugar molasses is unfit for food, due to the presence of nitroge- 
nous bodies, which give it a ver}^ unpleasant taste and smell. 

Process of Refining. — In refining raw sugar, a syrup is made, which 
is subjected to centrifuging and further defecation, using lime, clay, 
liquid blood, calcium acid phosphate, and other substances as clarifiers. 
The juices are then filtered, first through cloth bags and then through 
bone char, after which they are evaporated and allowed to crystallize, the 
resulting granulated sugar being separated, as in the case of raw sugar, 
by centrifugal machines. 

Granulated Sugar of commerce is without doubt the purest food product 
on the market, being generally 99.8% sucrose. It is usually treated with 
an extremely weak solution of ultramarine to counteract the natural 
yellow color. 

The syrup from which the granulated sugar is separated forms the 
"golden," or "drip," syrup used on the table. Its typical composition 
is as follows: Sucrose, 40%; reducing sugars, 25%; water, 20%; organic 
matter, 10%; ash, 5%. 

The dry sugars, whether white or brown, are rarely subjected to 
adulteration. 

Maple Sap. — The sap of the maple tree, Acer saccharinum, or Acer 
harbatum, furnishes a sugar considerably prized for its peculiar flavor. 
The maple sugar industry is largely confined to the northeastern states 
and to Canada, and the maple sugar season is generally limited to six 
weeks or two months in the spring. 

The following are minimum and maximum figures from the analyses 
of five samples of maple sap made in Massachusetts: 

Specific gravity i .007 to i .015 

Sucrose 0.769 " 2.777 

Reducing sugar '' 0.012 

The ash of maple sap varies from 0.04 to o. i per cent. Albuminoids 
are present in amount varying from 0.008 to 0.03 per cent. 

Maple Sugar and Syrup are made by simply boiling down the sap 
to the proper consistency, usually in open pans, and removing the scum 



SUGAR. AND SACCHARINE PRODUCTS. 



571 



with great care, since this contains nitrogenous matters that would cause 
fermentation in the finished product. Pure cane sugar is never com- 
mercially produced from the maple sap, since the refining process would 
deprive it of the flavor which gives to maple sugar the chief value. 

McGill gives the following as the average analyses of six samples 
of maple syrup of known purity: 





Saccharim- 
eter Invert. 


Cane Sugar 
by Clerget. 


By Copper. 


Ash. 


Water. 




Saccharim- 
eter Direct. 


Reducing 
Sugar. 


Cane Sugar. 


SoUds. 


+ 62.2 


— 21.2 62.4 


-42 


63-36 


•53 


35-70 


64.30 



The variation in the composition of pure maple products is shown 
by the following table compiled by A. H. Bryan * from analyses published 
by Hortvetjt Jones, :{: and Winton§, and some sixty analyses made at 
the sugar laboratory of the Bureau of Chemistry, U. S. Department of 
Agriculture. 



Maple Sugar. 



Mini- 
mum. 



Maxi- 
mum. 



Average. 



Maple Syrup. 



Mini- 
mum. 



Maxi- 
mum. 



Average. 



Water per cent 

Direct polarization " 

Invert sugar " 

Lead number 

Total ash per cent 

Soluble ash " 

Insoluble ash " 

Alkalinity of soluble ash 

Alkalinity of insoluble ash 

Ratio of insoluble to soluble ash 

Iodine reaction 

Polarization at 87° after inversion. . . . °V. 
Malic acid value 



72.6 
1. 16 
1.83 
0.64 

0-33 
0.20 
0.40 



— 2.0 
0.65 



87.4 
8.37 
2.48 
1.32 
0.67 
0.87 

0-95 
1.72 



+ 2.0 
1.67 



2.23 
0.91 
0.46 
0.46 
0.63 
0.94 
1 .00 
none 



Not m 

51-0 
0-34 
1. 19 
0.46 
o. 21 
0.14 
0.26 
0.31 
0.60 



ore tha 


n 32.0 


62.2 




9.17 




2.03 


1-49 


1. 01 


0.60 


0.63 


0.38 


0.56 


0.23 


0.68 


0.50 


0.94 


0.54 



3.20 



■ 2.0 

0.41 



+ 2.0 

1.76 



.78 



Partial ash analyses of maple products and brown sugar have been 
made by Jones il with the following maxima and minima results: 



* U. S. Dept. Agric, Bur. of Chem., Circular No. 40, p. 10. 

t Jour. Am. Chem. Soc, 26, 1904, p. 1523. 

X Vt. Agric. Exp. Sta. Rep., 1904, p. 446; 1905, p. 315. 

§ Jour. Am. Chem. Soc, 28, 1906, p. 1204. 

II Loc. cit., 1905, p. 331. 



:>/ 



FOOD INSPECTION .-IND .4\.4LySIS. 







, 


loo Parts of Ash Contain 




Ratio of 








Nuntber 
















of 
















CaO. 


KsO. 


SOs. 


CaO to KsO 


CaO to Si.X> 


K-O to SOs 














X 1 00. 


\ lOO. 


X lOO, 


Maple syrup: 


Min 


1 


iS.oi 


30.00 


0.68 


150 


3-4 


1.0 




Max. .. 


1 


23.9s 


3S-0S 


= •30 


iSi 


12.7 


7--^ 


Maple sugar: 


Min 


4 i 


21.03 


1S.26 


1.51 


57 


5-- 


5-1 




Max 


o. i 


oi-74 


33-95 


2.42 


153 


10.4 


0-4 


Brv^wn fugar; 


Min 


4* ! 


4.17 


30-72 


4 -58 


-57 


27 


II 




Max 


i 


21. 02 


55-40 


17.78 


940 


157 


5^"^ 



* Including one analysis by Hortvet. 



U. S. Standards for Maple Products. — Maple Sugar is the solid 
product rcsuhing from the cvaporaiion of maple sap, and contains in the 
water-free substance not less than 0.65^^1 of maple sugar ash. 

Maple syrup is syrup made by the evaporation of maple sap or bv the 
solution of maple concrete, and contains not more than ^j^ j of water 
and not less than 0.45' i of maple syrup asli. 

Adulteration of Maple Sugar and Syrup. — The chief adulterants of 
maple sugar are brown, or molasses sugar, and white, or retined sugar, 
the latter being often ustxi in mixture with burnt or inferior maple stock, 
which itself would be abnormally dark in color and of a rank taste. 
Maple syrup is commonly adulterated with a syrup made from refmed 
cane sugar, less often with golden or drip syrup, or molasses. Glucose, 
which formerly was a common adulterant, is now seldom employed. 

Rejined Sugar or retined sugar s}Tup added to maple products, while 
not greatly affecting the polarization, diminishes the percentage of total 
ash and the lead number, as well as the malic acid value and ash constants. 
The ash of maple sugar should not be less than 0.04*^^ and of maple 
s\Tup not less than 0.45^ i, while the lead number of maple sugar should 
not be less than 1.83 and of maple syrup not less than i.iq. 

According to analyses by Jones and Hortvet, brown sugar of various 
grades contains from 0.59 to 4.33*^^1 of total ash, some of the grades with 
low ash content, or s}Tups made from them, not being distinguishable 
from maple sugar or maple syrup respectively by this determination alone; 
the ratio of insoluble to soluble ash, however, is commonly higher in 
brown sugar than in maple products. It is frequently possible to identify 
brown, or molasses sugar, especially when it forms the larger portion 
of the alleged maple sugar or syrup, by the physical sense of taste, ^^'hen 
the perfectly characteristic taste of brown, or molasses sugar, or of ' drip 
S}Tup," so far predominates over the maple tlavor as to be unmistakable. 



SUGAR AND SACCHARINE PRODUCTS. 573 

especially in cases vihere the maple flavor is entirely lacking, one need 
have little hesitation in condemning the product.* 

Glucose in maple products is detected by [xjlarization both before and 
after inversion. A reading of the inverted solution much in excess of 
3 degrees \'entzke at 87*^ C. furnishes evidence of the presence of this 
arjulterajil. 

Sorghum (Andropogon sorghum, \-ariety saccharatus) has for many 
years been grown quite extensively in the southern and western states, 
and used as a source of syrup, but only in recent years has it been found 
practicable to produce crystallized cane sugar from it on account of the 
presence of starch, uncrystallizable sugar, etc. 

Much exjx^rimental work has been done of late along this line by the 
U. S. Department of Agriculture. The sorghum plant is as yet, however, 
a very small factor in the production of cane sugar, though much progress 
is being made. 

The comjxjsition of the juice of the sorghum plant is shown by the 
following results of analyses of eleven varieties made by Hardin :t 

Total solids, . . : 1 5 - 97 to i8 . 7 1 

Specific gravity i .0656 " i .0775 

Solids not sugar 5.02 " 10.63 

Cane sugar 2.81 " 8.01 

Reducing sugars 3.87 " 7.55 

Some varieties of sorghum juice have been known to contain 15 or 
even 17 per cent of sucrose. 

In making syrup from sorghum, the ripe canes are crashed, the juice 
is heated with milk of lime, and the scum removed. The juice is then 
concentrated usually in ojx^n pans to the required consistency. 

GEAPE SUGAR, OR DEXTROSE, 

Dextrose (C6H,206 + H20), designated J-glucose by Fischer and 
known in its commercial form a? starch sugar, occurs in honey with 
le\ailose, and in fruits with both levulose and cane sugar. It is produced 
by the action of dilute acids or of certain ferments on starch, dextrin, 
or cane sugar. Grapes contain about 15% of dextrose. Anhydrous 

* The sense of taste, if properly cultivated, and with its limitations recognized, should 
be entitled to as much consideration as the other senses in forming an opinion. Taste and 
smell are often ver>- useful factors in detecting adulterants, but should of course be used 
with discretion. 

t U. S. Dept. of .^ric, Div. uf Chem., Bui. 37, p. 75. 



574 FOOD INSPECTION AND AN /I LYSIS. 

dextrose is soluble in 1.2 parts of cold water. It is soluble in alcohol, but 
less so than cane sugar. It is much less sweet than cane sugar. 
The specific rotary power of dextrose is 

[«]z5 = 52.3, [a:]y=58. 

A normal solution of dextrose on the Soleil-Ventzke scale polarizes at 
78.6°. For the commercial preparation of dextrose see p. 576. 

U. S. Standards for Various Sugars. — Standard 70 sugar, or brewers* 
sugar, is hydrous starch sugar containing not less than 70% of dextrose, 
and not more than 0.8% of ash. 

Standard 80 sugar, climax, or acme sugar, is hydrous starch sugar 
containing not less than 80% of dextrose, and not more than 1.5% of ash. 

Standard anhydrous starch sugar is anhydrous starch sugar contain- 
ing not less than 95% of dextrose without water of crystallization, and 
not more than 0.8% of ash. 

The ash of these standard products consists almost entirely of chlorides 
and sulphates of lime and soda. 

LEVULOSE. 

Levulose, also known as c?-fructose and /-cJ-fructose, occurs in foods 
as the product of inversion of cane sugar. It is prepared by the action 
of dilute acids on inulin. Normally it is in the form of a syrup, but 
with extreme care pure anhydrous levulose can be obtained. Diabetene 
is a commercial form of dry levulose. Levulose is formed with dextrose 
in the inversion of cane sugar (p. 565), and with dextrose occurs in honey 
and in many fruits. The specific rotary power of levulose varies with 
the temperature. At 15° C. [«]£,= -98.8°, decreasing by 0.6385° for 
each degree increase in temperature. Its left-handed reading on the 
Ventzke sugar scale at 15° C. is equivalent to 148.6°. Levulose is sweeter 
than dextrose. Its reducing power on Fehling's solution is assumed 
to be the same as that of dextrose. 

MALT SUGAR, OR MALTOSE. 

Maltose (CijHjjOjj+HjO) is of little importance from the standpoint 
of the food analyst, excepting as an ingredient of commercial glucose, 
and as being the sugar produced by the action of ptyaline, the ferment 
of the saliva on the starch of food in the ordinary process of digestion. 
When gelatinized starch is subjected to treatment with malt extract at 
55° to 60° C, it is converted into dextrin and maltose as follows: 

CigHgoOiji-l- H2O = CgHioOs-}- C12H2.O11. 

Starch . Dextrin Maltose 



SUGAR AND SACCHARINE PRODUCTS. 575 

In its commercial preparation maltose is separated from dextrin by 
crystallization in alcohol. By the action of weak acids and heat both 
dextrin and maltose are further converted into dextrose. 

Maltose usually crystallizes in minute needles, and its molecule of 
water is expelled at 110° C. It is somewhat less soluble in water than 
dextrose. It is slightly soluble in alcohol, though less than sucrose. So- 
lutions of maltose possess the property of birotation; i.e., when freshly 
prepared they do not at once assume their true optical activity. The 
rotation of a freshly prepared solution of maltose increases on standing, 
requiring several hours to reach its maximum. The specific rotary 
power, according to O'Sullivan, of anhydrous maltose is [a]^= 139.2^ 
[a]y= 154.5. For hydrated maltose [a]^ would thus be 132.2. 

A normal solution of maltose on the Soleil-Ventzke scale should po- 
larize at 198.8°. 

DEXTRIN. COMMERCIAL GLUCOSE. 

Dextrin, (C6Hh)05)„, possesses more the nature of a gum than of a 
sugar, and is sometimes called British gum. It is said to occur naturally 
in the sap of various plants, but this is not definitely assured. 

It undoubtedly occurs in beer and in bread crust, and is one of the 
constituents of commercial glucose. Like starch, it is convertible by 
hydrolysis with acid into dextrose. By treatment of starch with malt 
extract or diastase, starch is converted into dextrin and maltose, these 
two bodies being separated, in the commercial preparations of dextrin, 
by repeated treatment with alcohol. 

Dextrin is an uncrystallized, colorless, tasteless body, capable of 
being pulverized. It is readily soluble in water, slightly soluble in dilute 
alcohol, but insoluble in alcohol of 60% or stronger. It is not colored 
by iodine, and exercises no reducing action on alkaline copper solution.. 
Its specific rotar}'- power is [«]£>= 200, [a]i=22 2. 

Amylodextrin, erythrodextrin and achpoodextrin are intermediate 
products formed in the transformation of starch into dextrose. Amylo- 
dextrin is colored purple and erythrodextrin red by iodine solution, while 
achroodextrin produces no coloration. It is probable that some of these 
dextrins are not simple substances. 

Commercial Glucose, otherwise known as mixing syrup, crystal syrup, 
and starch, or corfi syrup, is a heavy, mildly sweet, colorless, semi-fluid 
substance, having a gravity of 40° to 45° Baume. It is largely used as 
an adulterant of maple syrup, molasses, honey, drip syrup, and jellies 
and jams, and as an ingredient of confectionery. 

In France and Germany it is made from potato starch, but in the United 



576 FOOD INSPECTION ANn ANALYSIS. 

States mainly from corn starch. The conversion is effected by boiling 
with dilute sulphuric or hydrochloric acid, after which the acid is neutral- 
ized with marble dust, or sodium carbonate respectively, the juice is 
filtered through bone black, and finally concentrated by evaporation, 
the degree of conversion and of concentration depending on whether 
the liquid glucose or the solid dextrose is wanted for the final product. 
The end product obtained by complete conversion is the dry commercial 
grape sugar, or dextrose, which is purified by repeated crystallization. 

Commercial glucose is a mixture of dextrin, maltose, and dextrose 
of the following varying composition: 

Dextrin 29.8% 1045-3% 

Maltose 4.6% "19.3% 

Dextrose 34-3% "36-5% 

Ash 0.32% " 0.52% 

Water 14-2% "17.2% 

Calcium sulphate is usually found in the ash if sulphuric acid was used 
for conversion. 

Solid commercial grape sugar, or dextrose, has the following com 
position: 

Dextrin 0% 9- iVo 

Maltose 0% 1.8% 

Dextrose 72% 99-4% 

Ash 0.3% 0.75% 

Water 0.6% 17.5% 

U. S. Standard glucose, mixing glucose, or confectioners^ glucose, is color- 
less glucose, varying in density between 41° and 45° Baume, at a tempera- 
ture of 100° F. (37.7° C). It conforms in density, within these limits, to 
the degree Baume it is claimed to show, and for a density of 41° Baume 
contains not more than 21% of water, and for a density of 45° not more 
than 14%. It contains on a basis of 41° Baume not more than 1% of 
ash, consisting chiefly of chlorides and sulphates of lime and soda. 

Healthfulness of Glucose. — The analyst alleging commercial glucose 
as an adulterant is frequently asked in court as to its healthfulness, so 
that the following conclusions of a committee appointed some years ago 
by the National Academy of Sciences to ascertain among other things 
whether there is any danger attending the use of this product in food are 
in point: "First, that the manufacture of sugar from starch is a long- 
established industry, scientifically valuable and commercially important; 



SUGAR AND SACCHARINE PRODUCTS. 577 

second, that the processes which it employs at the present time are unob- 
jectionable in their character and leave the product uncontaminated; 
third, that the starch sugar thus made and sent into commerce is of excep- 
tional purity and uniformity of composition and contains no injurious 
substances; and fourth, that though having at best only about two- 
thirds the sweetening power of cane sugar, yet starch sugar is in no way 
inferior in healthfulness, there being no evidence before the committee 
that maize starch sugar, either in its normal condition or fermented, has 
any deleterious effect upon the system, even when taken in large quan- 
tities." 

MILK SUGAR, OR LACTOSE. 

Lactose (CijH^jOn+HjO) is prepared commercially from skim- 
milk by coagulating with rennet and digesting the whey with chalk and 
aluminum hydroxide. The insoluble matter is filtered out, and the 
fihrate is concentrated in vacuo to a syrup, which, on standing, yields 
cr}'stals of lactose. The product is purified by repeated crystallization. 

Lactose ordinarily crystallizes in rhombic, hemihedral crystals. Its 
specific gravity is 1.525. Its water of crystallization is lost by drying at 
130° C. It is soluble in 6 parts of cold water, and in 2^ or less of boiling 
w^ater. It is insoluble in absolute alcohol and ether. It has a very slightly 
sweet taste. 

The specific rotary power of milk sugar, after remaining in solution 
long enough to overcome its birotation, is 

[a]/? = 52.5- 

In the ordinary souring of milk the lactose becomes converted into 
lactic acid. 

On heating lactose with dilute acids it undergoes inversion, forming 
dextrose and galactose in accordance with the formula given on p. 565, 
illustrating the inversion of cane sugar. 

Milk sugar is of considerable importance by reason of the large amount 
used of late in the preparation of modified milk for infant feeding. 

Grape sugar and cane sugar are to be looked for as adulterants of 
milk sugar. 

The purity of milk sugar is best established by titrating against Feh- 
ling's solution, 10 cc. of which are equivalent to 0.067 gram of lactose. 

RAFFINOSE. 

Raffinose, CisHgaOieSHjO, is a sugar belonging neither to the saccha- 
rose nor the glucose group, but to the so-called saccharoid group, the other 
members of which do not occur in foods. 



5/8 



FOOD INSPECTION AND ANALYSIS- 



Raffinose occurs in beet root molasses to the extent of from 3 to 4 
per cent. It is a crystalline, slightly sweet substance, soluble in water 
and slightly soluble in alcohol. It does not reduce Fehling's solution, 
but readily undergoes fermentation. On inversion it splits up into 
levulose and melibiose (C12H22O11). 

The melting-point of raffinose is 118° to 119° C. Its specific rotary 
power [a]£)= + 104.5 ^^ a temperature of 20° C. 

THE POLARISCOPE AND SACCHARIMETRY. 

A full discussion of the principles of polarized light and even a detailed 
description of their application to the polariscope will not be given here, 
but the reader who wishes full information along this line is referred to 
the various text-books, and especially to those of Tucker, Spencer, and 
Landolt,* in which various forms of polariscopes are described and their 
underlying principles discussed. 

The Soleil-Ventzke Saccharimeter is the one most commonly used 
in this country, being adopted as the standard for all United States govern- 
ment work. Fig. 102 shows this instrument, known as the half-shadow 




I K)0 f D 



Fig. 102. — Single-wedge Saccharimeter. 

apparatus, in its simplest form with a single movable wedge in its com- 
pensating system. 

An excellent light for work with this instrument is that furnished by 
the Welsbach burner, a convenient form of lamp being shown in Fig. iii, 
in which the burner is inclosed in a sheet-metal chimney of suitable con- 
struction. An argand, gas, or kerosene burner may however be used, 

* See references, p. 651. 



SUGAR AND SACCHARINE PRODUCTS. 579 

and in a late form of Schmidt and Haensch instrument, Fig. 103, a 
specially constructed incandescent electric lamp is supplied. 

The Single-wedge Saccharimeter. — The following description of the 
saccharimeter and directions for its use are from the revised regulations 
of the U. S. Internal Revenue Department. The tub*^ N, Fig. 102, con- 
tains the illuminating system of lenses and is placed next to the lamp; 
the polarizing prism is at O and the analyzing prism at H. The quartz 
wedge compensating system is contained in the portions of the tube marked 
PEG and is controlled by the milled head M. The tube / carries a small 
telescope, through which the field of the instrument is viewed, and just 
above is the reading-tube K, which is provided with a mirror and magnify- 
ing lens for reading the scale. 

The tube containing the sugar solution is shown in position in the 
trough between the two ends of the instrument. In using the instrument 
the lamp is placed at a distance of at least 200 mm. from the polarizing 
end; the observer seats himself at the opposite end in such a manner 
as to bring his eye in line with the tube /. The telescope is moved in or 
out until the proper focus is secured to give a clearly defined image, 
w^hen the field of the instrument will appear as a round, luminous 
disk, divided into halves by a vertical line passing through its center, 
and darker on one half of the disk than on the other, when the com- 
pensating quartz wedge is displaced from the neutral position. If the 
obser\'er, still looking through the telescope, will now grasp the milled 
head M and rotate it first one way and then the other, he will find 
that the appearance of the field changes, and at a certain point the 
dark half becomes light and the light half dark. By rotating the milled 
head delicately backward and forward over this point he will be able to 
find the exact position of the quartz wedge operated by it, in which the 
field is neutral, or of the same intensity of light on both halves. The 
three different appearances presented by the field are sho^vn in Fig. 106, 
opposite page 582, 

One of the compensating quartz wedges is fixed and the other is 
movable, sliding one way or the other according as the milled head is 
turned, so that for different relative positions of the two wedges a different 
thickness of quartz is interposed in the path of the polarized ray. By 
this means the amount of the rotation which the sugar solution or other 
optically active substance examined exerts upon the light polarized by 
the prism at O may be, as it were, counteracted by var>'ing the relative' 
position of the wedges. 



FOOD INSPECTION ANb /tNALYSIS. 



With the milled head set at the point which gives the appearance of 
the middle disk shown in Fig. io6, the eye of the observer is raised to the 
reading tube K, which is adjusted to secure a plain reading of the divisions, 
and the position of the scale is noted. It will be seen that the scale proper 
is attached to the quartz wedge, which is moved by the milled head; 
and attached to the other quartz wedge is a small scale called a vernier^ 
which is fixed, and which serves for the exact determination of the posi- 
tion of the movable scale with reference- to it. On each side of the zero 
line of the vernier a space corresponding to nine divisions of the movable 
scale is divided into ten equal parts. Bv this device the fractional part 
of a degree indicated by the position of the zero line is ascertained in 




Fig. 103. — Single-wedge Soleil-Ventzke Saccharimeter, mounted on Bock Stand and 
provided with Incandescent Electric Lamp. 

tenths; it is only necessary to count from zero until a line is found which 
makes a continuous line with one on the movable scale. 

With the neutral field, as indicated above, the zero of the movable 
scale should correspond closely with the zero of the vernier, unless the 
zero point is out of adjustment. 

Adjusting the Instrument. — If the observer desires to secure an exact 
adjustment of the zero of the scale, or in any case if the latter deviates 
more than one-half of a degree, the zero lines are made to coincide by 
moving the milled head and securing a neutral field at this point by 



SUGAR AND SACCHARINE PRODUCTS. 581 

means of the small key which comes with the instrument, and which 
fits a small nipple on the /e/^hand side of F^ the fixed quartz wedge of 
the compensating system. This nipple must not be confounded with 
a similar nipple on the right-ha.n^ side of the analyzing prism H, which 
it fits as well, but which must never he touched, as the adjustment of 
the instrument would be seriously disturbed by moving it. With the 
key on the proper nipple it is turned one way or the other until the 
field is neutral. Unless the deviation of the zero be greater than 0.5° it 
will not be necessar\' to use the key, but only to note the amount of the 
deviation, and for this purpose the observer must not be content with 
a single setting, but must perform the operation five or six times and take 
the mean of these different readings. If one or more of the readings 
show a deviation of more than 0.2° from the general average they should 
be rejected as incorrect. Between each observation the eye should be 
allowed a moment of rest. 

The Scale usually has no equal divisions on one side of the zero for 
reading right-handed polarization, and 20 equal divisions on the other 
side for left-handed polarization. The scale is an arbitrar)' one, based 
on the plan that a normal aqueous solution of pure cane sugar (26.048 
grams made up to 100 cc.) will read exactly 100° or divisions to the right 
of the zero. 

The accuracy of various portions of the scale may be verified by 
quartz control plates of varying thickness, usually mounted in tubes, 
the correct polariscopic reading of each of which plates has been accurately 
aetermined, this reading being as a rule marked on the tube. As the 
sugar value of such a quartz plate varies with the temperature, the 
temperature at which the particular reading marked thereon applies is 
usually specified, and in many cases a table giving its exact value at 
different temperatures from 10° to 35° accompanies the plate. 

The Double-wedge Saccharlmeter is shown in Fig. 104, the arrangement 
of the optical parts being also shown. 

In this instrument the two sets of wedges employed are of oppo- 
site optical properties, so that extreme accuracy may be arrived at by 
making the readings with both, the inaccuracies of one being compen- 
sated for by the other. Ordinarily in using this form, one movable wedge, 
say the one controlled by the right-hand milled screw head, is set at zero, 
while the reading of the sugar solution or other substance to be polar- 
ized is made with the other movable wedge. 

The Triple-shadow Saccharlmeter. — The latest form of saccharlmeter 



5S2 



FOOD INSPECTION AND ANALYSIS. 




Fig. 104. — Double-wedge, Triple-shade Soleil-Ventzke Saccharimeter. 

is the triple-shadow instrument, the construction of the polarizer being 
shown in Fig. 105. 

In this form the analyzer is the same as in the fore- 
going instruments, but the polarizer consists of one large 
and two small Nicol prisms I, II, and III, the construction 
and arrangement being such that when the compensating 
wedges are at the neutral point, sections i, 2, and 3 of 
the circular field (corresponding respectively to the prisms 
I, II, and III) are evenly lighted, forming a circular 
uniformly colored field, while in any other position of I — 
the wedges section i is dark while 2 and 3 are light or 
vice versa. The accompanying diagram, Fig. 106, shows 
the appearance of the field of this instrument in the three 
positions of the quartz wedge, viz., at the neutral point 
and at both sides thereof. 

The lamp used for illumination should be separated 
from the polariscope on account of the influence of its F^^. 105. 

heat on the readings. This is best accomplished by 
having the lamp in a separate compartment from the polariscope, so 




f 

i 




#■■ ■ j 




Fig. io6. — Appearance of the Field in the Half-shade (above) and Triple-shade (below) 

Saccharimeter. 



SUGAR ANO SACCHARINE PRODUCTS. 



5«3 



that both are on opposite sides of a partition, an opening in which tranS' 
mits the light. In any event some kind of screen should be interposed 
between the two. Best results are obtained if the room in which the 
obser^•ations are made is dark. 

Comparisons of Scales of Various Polariscopes. — Besides the Soleil- 
Ventzke instrument, there are various other forms of polariscope. Amono- 
the best kno\\-n of these are Laurent's, Wild's, and Duboscq's, all of 
which are made with scales reading in circular degrees, while in some 
cases modified forms have scales in which, like the Soleil-Ventzke, per- 
centages of sugar are directly read off. Some instruments are provided 
with double scales reacUng both circular degrees and percentages of sugar, 
and in certain of the Duboscq instruments additional scales for percent- 
ages of milk sugar and diabetic sugar are provided. 

In the Wild, Duboscq, and Laurent instruments the source of light 
is the sodium flame, yielding what is termed a monochromatic light. 
This is produced by fused sodium chloride passing through a Bunsen 
flame, various mechanical devices being employed for making the light 
continuous. In the \>ntzke instrument, as was stated above, the ordinary 
light from a bright gas or oil flame is used. 

For convenience in conversion of readings on one instrument to their 
equivalents on other scales, the following factors can be used: 



1° Ventzke 




=0.3468° 


angular rotation D. 


1° angular rotation 


D 


= 2-8835° 


\'entzke. 


1° Ventzke 




= 2.6048° 


Wild (sugar scale). 


1° Wild ('sugar scale) 


=0.3840° 


\'entzke. 


1° " 




=0.1331° 


angular rotation D. 


i" angular rotation 


D 


=0.7511° 


WUd (^ sugar scale) 


1° Laurent (^ sugar scale) 


=0.2167° 


angular rotation D. 


1° angular rotation 


D 


=4.6154= 


Laurent (sugar scale). 


1° Soleil-Duboscq 




= 0.2167° 


angular rotation D. 


1° " 




=0.2450° 


" j. 


1° " 




=0.620° 


Soleil-Ventzke. 


1° " 




= 1.619° 


Wild. 


1° Soleil-Ventzke 




= 1.608° 


Soleil-Duboscq (old scale). 


1° " 




= 1-593° 


" " (new scale). 


1° WCd 




= 0.611° 


" " (Wild normal weight 10). 


1° " 




= 1.223° 


, .. ■< << 20). 



Normal Weights of Sugar for Different Instruments. — The follow- 
ing normal weights (number of grams in loo cc. at 17.5° C.j are those on 
which the scales of the various instruments are based: Soleil-Ventzke, 
26.048; Soleil-Duboscq 16.35 (formerly 16.19); Wild, usually, 10 or 20; 
Laurent, 16.19. 

The International Commission for Uniform Methods in Sugar Analysis 
has decided to use for the \'entzke scale 26 grams and make up at 20^ C. 
to 100 metric cc, which figures are approximately equivalent to 26.048 
grams made up to 100 Mohr cc. 



584 FOOD INSPECTION y4ND /IN A LYSIS. 

Specific Rotary Power. — This is a theoretical term to express a stand- 
ard by which the various optically active substances may be compared, 
and is understood to mean the amount in angular degrees through which 
the plane of polarization of a ray of light of stated wave length is rotated 
by I gram of a given substance in aqueous solution of i cc. and forming 
a column i decimeter in length. The actual rotary power of a solution 
varies directly with the length of the column traversed by the light, with 
the concentration of the solution, and with the wave length of light, 
hence the need of a purely theoretical basis for purposes of comparison. 

The specific rotary power is usually expressed as [alb or [a\j, the 
letters D or j indicating the character of the light. Thus, D indicates 
the monochromatic light obtained from the sodium flame, named from the 
D line of Fraunhofer in the yellow portion of the spectrum, while j (from 
the French jaune) indicates what is known as the transition tint, the 
rose-purple color produced when ordinary white light passes through 
the polarizer and analyzer, placed with their principal sections parallel 
to each other and with a plate of quartz 3.75 mm. thick interposed between 
them.* 

The specific rotar}^ power is determined as follows: 

r 1 r 1 ^°°^ 

[ajo or [aX = -^, 

where a = observed angular rotation, 

c = grams of the substance in 100 cc. of the solution, and 
/ = length of the observation-tube in decimeters; or, in cases where, 
instead of the grams per 100 cc, the percentage composition is known 
(expressed by ^ = grams of the substance in 100 grams of the solvent), 

and the specific gravity (expressed by d), then [a\o or [0:].= ,, . 

put 

Birotation. — In polarizing solutions of all the common sugars other 
than sucrose the phenomenon of birotation should be taken into account, 
whereby a change in optical activity is shown by standing. Thus, solu- 
tions of dextrose, levulose, and lactose polarize much higher when freshly 
prepared than after long standing, requiring in some instances several 
hours before the lowest or normal figure is reached. Maltose, on the 
other hand, increases in polarization after standing in solution. By 

* Some confusion is caused by the adoption of the characters D and j, since both would 
naturally seem to indicate yellow light. The so-called transition tint above defined is, how- 
ever, complementary to the mean yellow, or jaune moyen, and it is the complementary coloJ 
and not the yellow itself that is indicated by the character / 



SUGAR AND SACCHARINE PRODUCTS. 585 

boiling the solution it may be at once brought to its correct reading. The 
desired result may also be accomplished by adding a few drops of ammo- 
nia, either treatment being resorted to before the solution is made up to 
the required volume. 

ANALYSIS OF CANE SUGAR AND ITS PRODUCTS. 

Qualitative Tests for Sucrose. — (a) Polariscope Test. — The substance 
to be tested, if not already in solution, is dissolved in water, and if the 
solution is not perfectly clear, is clarified by the pddition of alumina 
cream or by subacetate of lead (p. 586) and filtered. An observation 
tube is filled with the clear solution and the polariscope reading note:l. 
A measured portion of the same solution is then treated with one-tenth its 
volume of concentrated hydrochloric acid and is subjected to inversion 
(p. 588), after which the same tube as before is filled with the inverted 
solution and a second reading obtained, one-tenth of the observed reading 
being added for the true invert polariscopic reading. If the two readings 
are virtually the same, sucrose is absent, but, in the presence of sucrose, 
the second reading will be considerably lower than the first or may even 
be to the left of the zero. 

{b) Test with Nitrate oj Cobalt."^ — Prepare a 5% solution of cobaltous 
nitrate, and a 50% solution of potassium hydroxide. If the sugar solution 
to be tested contains dextrin or gums, these should first be removed 
by treatment with alcohol. 15 cc. of the sugar solution to be tested are 
mixed with 5 cc. of the cobaltous nitrate reagent, and 2 cc. of the potas- 
sium hydroxide solution are added. Sucrose produces under these con- 
ditions a permanent amethyst-blue color, while dextrose gives at first a 
turquoise-blue passing over into light green. In a mixture of the two 
sugars the color due to sucrose will predominate. 

According to Wiley, i part of sucrose in 9 parts of dextrose may be 
detected by this test. 

Analysis of Cane sugar. — In the case of commercial granulated or 
loaf sugar the sucrose determination is usually all that is necessary 
to determine its purity, and the same is true, as a rule, of the powdered 
white sugars. A fairly complete analysis of raw or brown sugar con- 
sists in the determinations of moisture, sucrose, invert sugar, ash, organic 
non-sugars, and quotient of purity. Care should be taken that the 
portion subjected to analysis is a fair representation of the whole, and is 
perfectly homogeneous. 

* Wiley, Ag. Anal., p. 189. 



586 FOOD INSPECTION AND ANALYSIS. 

Determination of Moisture.— 2 to 5 grams of the sample are dried 
in a flat, tared metal dish, to constant weight in vacuo, or in a McGill 
oven* in a current of air, at about 7o°C.,at which temperature levulose 
is not decomposed. For ordinary purposes sufficiently accurate results 
may be obtained by the A. O. A. C. method of drying to constant weight 
at 100° C. in a water oven. 

Determination of the Ash. — The residue from the moisture deter- 
mination is burned slowly and cautiously over a low flame until frothing 
has ceased. Afterwards increase the flame and ignite to a white ash 
at a low, red heat. 

In igniting saccharine substances which contain an appreciable amount 
of cane sugar, the contents of the dish will swell up and froth, unless 
great care be taken, to such an extent as to flow over the sides of the 
dish, occasioning loss and inconvenience. Such frothing may be largely 
held in check by directing the flame at first down from above upon the 
pasty mass, instead of from under the dish as ordinarily, till all is reduced 
to a dry char, afterwards continuing the ignition from below in the usual 
manner. 

Organic Non-sugars. — These consist mainly of compounds of organic 
acids, together with gum, coloring matter, albuminous bodies, etc. They 
are determined by difference between 100% and the sum of the sucrose, 
invert sugar, moisture, and ash. 

Quotient of Purity. — By this term is meant the percentage of pure 
■sugar in the dry substance. It is calculated by dividing the per cent 
of sucrose by the percentage of total solids and multiplying the result 
by 100. 

Determination of Sucrose by the Polariscope. — Reagents. — Stihace- 
tate of Lead Solution.^ — This is prepared by boiling for half an hour 430 
grams of normal lead acetate, 130 grams of litharge, and 1000 cc. of 

* A. McGill, Laboratory of Inland Revenue, Ottawa, Canada, has devised a forced- 
draft water-oven for drying at temperatures between 60° and 90° C. The oven is heated 
by means of ordinary gas-burners, and the temperature is controlled by introducing at the 
bottom of the oven a blast of air from a blower run by a small water-motor. Before dis- 
charging into the oven, the air-tube enters the water-chamber and is coiled a number of 
times in order to sufficiently warm the air before it enters the oven. The exit end of ihe 
air-tube is covered with a concavo-convex disk in order to distribute the blast and to pre- 
vent harmful currents. By regulating the burners and the flow of air, a fairly constant tem- 
perature can be obtained. The bottom of the oven is curved instead of flat, to prevent 
bumping when the water is boiling; a perforated plate serves as a false bottom. 

■j" U. S. P. lead subacetate may be used. This is sometimes sold under the name of 
Goulard's extract. 



SUGAR /^ND SACCHAR.INE PRODUCTS. 



587 



water. The mixture is allowed to cool and settle, when the super- 
natant liquid is diluted to 1.25 specific gravity with recently boiled water. 

Alumina Cream is prepared by dividing a cold, saturated, aqueous 
solution of alum into two unequal portions, to the larger of which add a 
slight excess of ammonia. Then add by degrees the remaining portion 
to a faint acid reaction. 

Process. — If the Soleil-Ventzke polariscope is to be used, weigh out 26.048 
grams of the sugar, which may conveniently be done in the German-silver, 
tared tray especially designed for this purpose, and which accompanies the 
Schmidt and Haensch polariscope, Fig. 107. If any other instrument than 




Fig. 107. — German-silver Sugar-tray with Tare. 



the Soleil-Ventzke is employed, weigh out the standard or normal weight 
for that instrument (see p. 583). Transfer the sugar by washing to a 
loo-cc. graduated sugar-flask, and if the solution is perfectly clear, as 
would be the case with a refined sugar, make up to the mark and shake 
to insure a uniform solution. If the solution is slightly turbid, or more 
or less opaque or dark-colored, a clarifier must be added before making 
up to the mark to obtain a clear solution for polarization. The kind 




-A Convenient Sugar-scale. 

and amount of claritier to be used depends on the nature of the sugar 
solution, and experience will soon indicate what is best adapted to given 
conditions. If the turbidity is only slight, from 5 to 10 cc. of alumina 
cream alone will often prove sufficient. In case of a very opaque solution, 
10 cc. of subacetate of lead solution will nearlv alwavs suffice. 



5^8 FOOD INSPECTION ANn ANALYSIS. 

For additional details as to clarification see page 614. under Molasses. 

After adding the clarifier, the flask is filled to the mark with water 
and shaken, the solution being poured upon a dry filter and the first 
few cubic centimeters of the filtrate rejected. A 200- mm. observation- 
tube is filled with the clear sugar solution and the polarization noted. 
If sucrose is the only optically active substance present, the direct read- 
ing on the polariscope will indicate its percentage. 

Process 0} Inversion. — In the presence of invert or other sugars the 
normal solution as above prepared is subjected to inversion as follows: 
Free a portion of the solution from lead by treating with anhydrous 
sodium carbonate, sodium sulphate or potassium oxalate, filter, place 
50 cc. in a loo-cc. flask, add 25 cc. of water and little by little, while 
rotating the flask, 5 cc. of 38.8% hydrochloric acid. Heat in a water 
bath at 70° C, so that the solution in the flask reaches 67° to 69° C. in 
two and one-half to three minutes. Maintain at 69° C. during seven to 
seven and one-half minutes, making a total time of heating of ten minutes. 
Remove the flask, cool the contents rapidly to 20° C, and dilute to 
100 cc. Polarize this solution in a 200-mm. tube provided with a lateral 
branch and a water jacket, passing a current of water around the tube 
to maintain a temperature of 20° C. 

The inversion may also be accomplished by allowing a mixture of 
50 cc. of the clarified solution, freed from lead, and 5 cc. of the acid to 
stand for 24 hours at not less than 20° C. or for 10 hours at not less than 25°. 

The sucrose is obtained by the following formula of Clerget, based on 
the rotation of cane sugar before and after inversion, 

„_ ioo(a — b) 

O — f 

142.66— //2 

where 5 = per cent of sucrose, a = direct polarization, 6 = invert polari- 
zation, and / = temperature. Note that if the direct polarization is to 
the right or positive, and the invert to the left or negative, then a-b would 
be the sum of the two polarizations. 

In many cases where it is almost impossible to obtain a colorless 
solution for polarization in the 200-mm. tube, a loo-mm. tube may be 
employed, and the readings multiplied by 2, or half the normal weight,* 
viz., 13.024 grams, of the sample may be taken and made up to 100 cc, 
the 200-mm. tube employed, and the readings multiplied by 2. 

♦Wherever the term "normal weight" occurs hereafter will be meant, unless otherwise 
noted, the normal weight of sugar for the Soleil-Ventzke polariscope, viz., 26 grams, and 
by a "normal solution" will be meant 26 grams in 100 cc. of water. Clerget's formula, as 
originally worked out by him, was not based on this normal weight, but on 16.35 grams. 
It is, however, applicable to 26 grams:-. . 



SUGAR AID SACCHARINE PRODUCTS. },': ) 

The determination of sucrose by the Clerget formula is apphcable 
to all mixtures of the common sugars excepting those in which lactose, or 
milk sugar, is present. 

Theory of Inversion. — On p. 565 a reaction is given showing that 
when sucrose is subjected to inversion by the action of dilute acids or 
of invertase or yeast it splits up into the two sugars dextrose and levulose, 
forming equal quantities of each. The dextrose is, however, dextro- 
rotary and the levulose lasvorotary. Invert sugar is the term applied 
to the mixture of dextrose and levulose formed by the inversion of sucrose. 
The specific rotary power of sucrose varies so little with the temperature 
as to be regarded for practical purposes as constant. At 87° a solution 
of invert sugar polarizes at zero. This is due to the fact that the rotary 
power of levulose, unlike that of sucrose and dextrose, varies with the 
temperature. At from 87° to 88° the left-handed rotation of the levulose 
balances the right-handed rotation of the dextrose in the invert sugar, 
hence the zero reading. As the temperature decreases from 87°, the 
rotary power of the levulose proportionally increases, till at 0° the normal 
invert sugar solution would polarize 44° to the left of the zero. On these 
facts Clerget's formula (p. 580) is based, assuming that a normal solution 
of pure cane sugar polarizes at -f 100°, while after inversion the reading 
for 0° temperature would be —44° and would decrease half a degree 
for each degree in temperature above 0°. Thus at 20° the invert reading 
would be —34. 

• Detection of Invert Sugar. — Methyl-blue Test. — This test depends on 
the decolorization of methyl blue by invert sugar. 20 grams of sugar are 
dissolved in water and made up to 100 cc. If the solution is not clear, 
sufficient subacetate of lead solution is added to clarify before making 
up to the mark, and the solution is filtered. Add to the filtrate enough 
10% sodium carbonate solution to make alkaline, and filter a second 
time. Take about 50 cc. of the filtrate in a casserole, add 2 drops of a 
1% solution of methyl blue, and boil over a free flame, noticing particu- 
larly the time the solution begins to boil. 

If the color disappears in one minute after boiling, there is present 
at least 0.01% of invert sugar. If it is not completely decolorized by 
three minutes' boiling, no invert sugar is present. 

Determination of Invert Sugar in Cane Sugar Products by the Polar- 
iscope, — While invert sugar is best determined by Fehling's solution as 
described elsewhere, it may be approximately estimated by the polari- 



5QO FOOD INSPECTION AND ANALYSIS. 

scope, though less satisfactorily. On p. 626 a method is given for the 
determination of levulose by polariscopic readings at two different tem- 
peratures. Since invert sugar is composed of equal parts by weight of 
dextrose and levulose, the percentage of levelose multiplied by 2 would 
give that of invert sugar. 

Test for Ultramarine in Sugar.* — A large amount of the sugar is 
dissolved in w^ater and the coloring matter is allowed to settle out, 
washing the residue several times by decantation. On treatment 
with hydrochloric acid, the blue color is discharged if due to ultra- 
marine. 

SUGAR DETERMINATION BY COPPER REDUCTION. 

Various convenient methods of determining sugars depend on the 
readiness with which certain of them, known as reducing sugars, act on 
copper salts, especially on the tartrate of copper, reducing it to cuprous 
oxide. 

This reducing power is exercised in a definite degree under fixed 
conditions, so that the amount of reducing sugar present may be accurately 
determined. Of the common sugars, sucrose is the only one that has 
no direct reducing action, but on undergoing inversion it is converted 
into reducing sugars, which are readily determined. 

Use of Fehling's Solution. — ^There are various well-known mixtures 
of copper sulphate, tartaric acid salts (usually Rochelle salts or cream 
of tartar), and alkalies, called after chemists who have employed them 
in the determination of the reducing sugars, each one possessing certain 
advantages, but none have become so widely adopted as Fehling's solu- 
tion, the use of which in one form or another is now well-nigh 
universal. 

There are a number of methods by w^hich Fehling's solution is employed 
for this purpose, both volumetric and gravimetric. The former are 
simpler and quicker of manipulation, and thus are preferable for com- 
mercial work where extreme accuracy is not required. The gravimetric 
methods are usually considered more delicate and accurate, calling for 
less skill, but more time in arriving at results, and with less of the " per- 
sonal element" than the volumetric. 

Some modifications of the Fehling method, especially as carried out 
gravimetrically, differ for the various reducing sugars to be determined, 

* Leffmann and Beam, Select Methods of Food Analysis, p. 126. 



SUGAR AND SACCHARINE PRODUCTS. 591 

and others are carried out alike, so far as manipulation is concerned, whether 
the particular sugar to be determined be dextrose, maltose, or lactose. 

While, strictly speaking, the reducing power of dextrose, IcAoilose, and 
invert sugar are not identical, it is customary in commercial work to 
regard them as such, and no appreciable error arises in consequence 
except in extreme cases. Thus the term "reducing sugars" is com- 
monly applied indiscriminately to dextrose, le\Tilose, and invert sugar, 
the same factor being used in calculating either, in mixtures wherein 
other reducing sugars, as lactose, maltose, etc., having ^^ddely different 
reducing powers are absent. 

Fehling's solution is made up in two separate parts as follows: 

A. Fehling's Copper Solution. — 34.639 grams of carefully selected 
cr}'stals of pure copper sulphate dissolved in water and diluted to exactly 
500 cc. 

B. Fehting's Alkaline Tartrate Solution. — 173 grams Rochelle salts 
and 50 grams sodium hydroxide are dissolved in water and diluted to 
exactly 500 cc. 

The Fehling solution should be standardized by dissolving 0.5 gram 
of pure anhydrous dextrose in water, and diluting to exactly 100 cc. 10 cc. 
of this dextrose solution should exactly reduce the copper in 10 cc. of 
the Fehling (5 cc. each of solutions A and B) when conducted according 
to the volumetric process described below. 

VOLUMETRIC FEHLING PROCESS. — For determining dextrose, levulose, 
or invert sugar in a raw or brown sugar, make a solution of the sugar of such 
a strength that an accurately weighed amount dissolved in water and 
made up to 100 cc. shall contain not more than 1% of the reducing sugar, 
as nearly as can be guessed at with reference to the class of sugar under 
examination, or from a rough preliminary titration. 

^Measure accurately into a flask of about 250 cc. capacity 5 cc. Feh- 
hng's copper sulphate solution, A, and 5 cc. of the alkali solution, B. 
Add about 40 cc. of water, mix and boil over a free flame, with copper 
gauze beneath the flask. While still boiling, add from a pipette or burette 
a measured quantity of the sugar solution, prepared as above, until the 
copper after three minutes' boiling is all reduced to cuprous oxide. The 
end-point is determined in a variety of ways. Practice Tvill soon enable 
the eye to judge the near approach of the end-point by the changes in color 
that take place in the solution, which turns from a deep blue, first to green, 
then to a dull-red tint, and finally to a bright brick-red. The sugar- 
containing solution may be added from the burette quite rapidly until 



592 



FOOD INSPECTION /IND /IN/f LYSIS. 



the solution reaches the dull-red tint, after which care is taken to add a 
little at a time, keeping account of the total amount added. If the flask 
be removed from the flame, and the bright, diffused light from a window 
viewed through the solution with the eye on a level with the surface, a thin 
film scarcely wider than a line will be observed just below the surface 
(see Fig. 109), which is blue so long as some of the copper in the solu- 
tion remains unreduced. When, however, all the 
copper has been reduced, this film ceases to be 
blue and becomes colorless or yellow. 

If the film is not at once apparent, it may often 
be made quite noticeable by simply diluting the 
solution in the flask with water. At the approach 
of the end-point the sugar-containing solution 
should be added a xery little at a time. The 
exact end-point is best arrived at by decanting a 
few drops of the mixture in the flask through a 
filter, acidifying the filtrate with acetic acid, and 
adding a drop of a solution of ferrocyanide of 
potassium. As long as there is unreduced copper 
present, a precipitate or brown-red coloration will 
appear when the ferrocyanide is added. The 
sugar solution toward the end should be added 
to the contents in the flask in small installments 
(say half a cubic centimeter each time), boiling 
the liquor for at least three minutes after each 
addition, until no brown-red coloration is pro- 
duced by adding the ferrocyanide to a little of the filtered acidified liquid. 
"When the number of cubic centimeters of sugar solution necessary to 
reduce the copper has thus been determined, a second titration should be 
made to verify the first, running the entire amount of sugar-containing 
liquid found necessary in the first case into the second flask. 

The equivalents of 10 cc. of Fehling's solution in the above volumetric 
method are, in terms of the common reducing sugars, as follows: 




Fig. 109. — Flask and Con- 
tents used in Volumetric 
Fehling Determinations. 
Showing layer just be- 
neath the surface, the 
color of which indicates 
the end-point in adding 
the sugar-containing li- 
quid. 



{invert sugar, i 
dextrose, or >- will reduce 10 cc. Fehling's solution, 
levulose ) 
( cane sugar "j 
0.0475 gram of - after in- V will reduce 10 cc. Felihng's solution. 
( version j 



SUGAR AND SACCHARINE PRODUCTS. :^g- 

0.0807 gram of maltose will reduce 10 cc. Fehling's solution. 

0.067 gram of lactose " " 10 cc. " ** 

Suppose, for example, a sample of brown sugar is to be examined 
for invert sugar. This class of sugar has usually from 2 to 6 per cent 
of invert sugar. Hence, if 10 grams of the sample are dissolved in 100 
cc, the resulting solution will contain not more than 1% of invert sugar. 

Suppose 12.9 cc. of this 10% sugar solution were found by the above 
process to reduce 10 cc. of Fehling's solution. 

10 cc. Feliling's solution are equivalent to 0.05 gram invert sugar. 

Therefore 12.9 cc. of the sugar solution contain 0.05 gram invert- 
sugar. 

100 cc. sugar solution contain 10 grams sample, and 12.9 cc. contain 

1.29 grams sample, the equivalent of 0.05 gram invert sugar. 

_-. . 0.05X100 
Hence per cent mvert sugar = = 3.9. 

Gravimetric Fehling Processes.— In determining reducing sugars 
by gravimetric processes, a measured volume of the sugar solution is 
allowed to act upon a measured volume of hot Fehling's solution for a 
fixed time, thus forming cuprous oxide. This may be dried and weighed 
direct, but is more commonly converted either into cupric oxide by ignition, 
or into metallic copper by reduction with hydrogen or by electrolysis. 
In any case the sugar is calculated from the weight of the cuprous oxide, 
the cupric oxide, or the metallic copper (whichever method be used) by 
the employment of the proper factor, or by the use of tables compiled 
for the purpose. 

N'oie. — Much difference of opinion exists as to the best and most 
accurate Fehling gravimetric method to employ. For the determination 
of dextrose, the Association of Official Agricultural Chemists has given 
its approval to the Allihn method, wherein the cuprous oxide deposited 
is further reduced to metallic copper and the dextrose calculated from 
the copper by Allihn's table. 

The author for two reasons prefers the method of O'SuUivan as 
employed by Defren, with the use of the Defren tables, in accordance 
with which the reducing sugar is expressed in terms of its equivalence 
to cupric oxide, first because of its comparative simplicity, involving as it 
does less processes than the Allihn method (each additional process 
introducing a possible source of error), and, second, because the same 
method as carried out is applicable for the determination not only of 
dextrose, but also of maltose and lactose, Defren having worked out 



594 FOOD INSPECTION AND /IN A LYSIS. 

tables adapted for them all. Munsen and Walker* have also devised a 
simple method with accompanying tables, adapted, with a uniform system 
of procedure, to the determination of the various reducing sugars. In 
using the tables for dextrose, maltose, and lactose compiled by Allihn, 
Wein, and Soxhlet, the method employed must in each case be carried 
out in strict accordance to the minutest details adopted by each of the 
above authorities, and they are by no means uniform. 

The Defren-0 'Sullivan Method.t— Mix 15 cc. of Fehling's copper 
solution, A (p. 591), \\'ith 15 cc. of the tartrate solution, B, in a quarter- 
liter Erlenmeyer flask, and add 50 cc. of distilled water. Place the flask 
and its contents in a boiling water bath and allow them to remain five 
minutes. Then nm rapidly from a burette into the hot liquor in the 
flask 25 cc. of the sugar solution to be tested (which should contain not 
more than one-half per cent of reducing sugar). Allow the flask to remain 
in the boiling water bath just fifteen minutes after the addition of the 
sugar solution, remove, and with the aid of a vacuum filter the contents 
rapidly in a platinum or porcelain Gooch crucible containing a layer 
of prepared asbestos fiber about i cm. thick, the Gooch with the asbestos 
having been previously ignited, cooled, and weighed. The cuprous 
oxide precipitate is thoroughly washed with boiling distilled water till 
the water ceases to be alkaline. 

The asbestos used should be of the long-fibered variety, and should 
be specially prepared as follows: Boil first with nitric acid (specific 
gravity 1.05 to i.io), washing out the acid with hot water, then boil with 
a 25% solution of sodium hydroxide, and finally wash out the alkali with 
hot water. Keep the asbestos in a wide-mouthed flask or bottle, and 
transfer it to the Gooch by shaking it up in the water and pouring it 
quickly into the crucible while under suction. 

Dr}^ the Gooch with its contents in the oven, and finally heat to dull 
redness for fifteen minutes, during which the red cuprous oxide is con- 
verted into the black cupric oxide. If a platinum Gooch is used (and 
this variety is preferred by the writer), it may be heated directly over 
the low flame of a burner. If the Gooch is of porcelain, considerable 
care must be taken to avoid cracking the crucible, the heat being increased 
cautiously and the operation preferably conducted in a radiator or muffle. 
After oxidation as above, the crucible is transferred to a desiccator, cooled, 
and quickly weighed. From the milligrams of cupric oxide, calculate 
the milligrams of dextrose from the following table: 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 241. 

t Jour. Am. Chem. See, 18, 1896, p. 749, and Tech. Quart., 10, 1897, p. 167. 



SUGAR. AND SACCHARINE PRODUCTS. 



595 



DEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, 

AND LACTOSE. 



Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


Milligranis 

of Cupric 

Oxide. 


Milligrams 


MiUigrams 


Milligrams 


of Dextrose. 


of Maltose. 


of Lactose, i 


of Dextrose. 


of Maltose. 


of Lactose. 


3° 


13.2 


21.7 


18.8 ; 


80 


35-4 


58.1 


50-5 


31 


13-7 


22.4 


19-5 


81 


35-9 


58.9 


■5I-I 


32 


14. 1 


23-1 


20.1 


82 


36-3 


59-6 


51-7 


33 


14.6 


23-9 


20.7 


83 


36.8 


60.3 


52-4 


34 


15-0 


24.6 


21.4 


84 


37-2 


61. 1 


53-0 


35 


15-4 


25-3 


22.0 


85 


37-7 


61.8 


53-6 


36 


15-9 


26.1 


22.6 


86 


38-1 


62.5 


54-3 


37 


16.3 


26.8 


23-3 


87 


38-5 


63-3 


54-9 


38 


16.8 


27-5 


23-9 


88 


39-0 


64.0 


55-5 


39 


17.2 


28.3 


24-5 


89 


39-4 


64-7 


56.2 


40 


17-6 


29.0 


25.2 


90 


39-9 


65-5 


56.8 


41 


18. 1 


29.7 


25.8 


91 


40.3 


66.2 


57-4 


42 


18.5 


30-5 


26.4 


92 


40.8 


66.9 


58.1 


43 


19.0 


31.2 


27.1 


93 


41.2 


67.7 


58.7 


44 


19.4 


31-9 


27.7 


94 


41.7 


68.4 


59-3 


45 


19.9 • 


32-7 


28.3 


95 


42.1 


69.1 


60.0 


46 


20.3 


33-4 


29.0 


96 


42.5 


69-9 


60.6 


47 


20.7 


34-1 


29.6 


97 


43-0 


70.6 


61.2 


48 


21.2 


34-8 


30.2 


98 


43-4 


71-3 


61.9 


49 


21.6 


35-5 


30.8 


99 


43-9 


72.1 


62.5 


50 


22.1 


36.2 


31-5 


100 


44.4 


72.8 


63.2 


51 


22.5 


37-0 


32-1 


lOI 


44.8 


73-5 


63 -8 


52 


23.0 


37-7 


32-7 


102 


45-3 


74-3 


64-4 


53 


234 


38-4 


33-3 


103 


45-7 


75-0 


65.1 


54 


23.8 


39-2 


34-0 


104 


46.2 


75-7 


65-7 


55 


24.2 


39-9 


34-6 


105 


46.6 


76-5 


66.3 


56 


24.7 


40-5 


35-2 


106 


47-0 


77-2 


67.0 


57 


25.1 


41-3 


35-9 


107 


47-5 


77-9 


67.6 


58 


25-5 


42.1 


36-5 


108 


48.0 


78.7 


68-2 


59 


26.0 


42.8 


37-1 


109 


48.4 


79-4 


68. 9 


60 


26.4 


43-5 


37-8 


no 


48.9 


80.1 


69-5 


61 


26.9 


44-3 


38-4 


III 


49-3 


80.9 


70.1 


62 


27-3 


45.0 


39-0 


112 


49-8 


81.6 


70-8 


63 


27.8 


45-7 


39-7 


"3 


50.2 


82.3 


71-4 


64 


28.2 


46-5 


40.3 


114 


50-7 


83.1 


72.0 


65 


28.7 


47.2 


40.9 


115 


=;i.i 


83-8 


72-7 


66 


29.1 


47-9 


41-6 


116 


51.6 


84-5 


73-3 


67 


29.5 


48. 6 


42.2 


117 


52-0 


85-2 


74.0 


68 


30.0 


49-4 


42.8 


118 


52-4 


85-9 


74-6 


69 


30.4 


50.1 


43-5 


119 


52-9 


86.6 


75-2 


70 


30-9 


50. 8 


44-1 


120 


53-3 


87.4 


75-9 


71 


3^-3 


51.6 


44-7 


121 


53-8 


88.1 


76.6 


72 


31.8 


52-3 


45-4 


122 


54-2 


88.9 


77-2 


73 


32.2 


53-0 


46.0 


123 


54-7 


89.6 


77-9 


74 


32.6 


53-8 


46.6 


124 


55-1 


90-3 


78. 5 


75 


33-^ 


54-5 


47-3 


125 


55-6 


91.1 


79.1 


76 


33-5 


55-2 


47-9 


126 


;6.o 


91.8 


79-8 


77 


34-0 


56.0 


48.5 


127 


56-5 


92-5 


80.4 


78 


34-4 


56-7 


49-2 


128 


56-9 


93-3 


81. 1 


70 


34.9 


57-4 


49-8 


129 


57-3 


94.0 


81.7 



596 



rOOD INSPECTION AND ANALYSIS. 



DEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, 
AND 'L.'K.CTOS^— {Continued). 



Milligrams 

of Cupnc 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


Milligrams 
of Cupric 


Milligrams 


1 
Milligrams 


Milligrams 


of Dextrose. 


of Maltose. 


of Lactose. 


Oxide. 


of Dextrose. 


of Maltose. 


of Lactose. 


130 


57-8 


94-8 


82.4 


180 


80.4 


131. 8 


114. 6 


131 


58-2 


95-5 


83.0 


181 


80.8 


132-5 


115. 2 


132 


58-7 


96.2 


83.6 


182 


81.3 


133-2 


115. 8 


133 


59-1 


97.0 


84.2 


183 


81.8 


134-0 


116.5 


134 


59-6 


97-7 


84-9 


184 


82.2 


134-7 


117. 1 


135 


60.0 


98-4 


85-5 


185 


82. 7 


135-5 


117. 8 


136 


60.5 


99-2 


86.1 


186 


83.1 


136.2 


118. 4 


137 


60.9 


99-9 


86.8 


187 


83-5 


136.9 


119. 1 


138 


61.3 


100.7 


87.4 


188 


84.0 


137-7 


119.7 


139 


61.8 


101.4 


88.1 


189 


84-4 


138.4 


120.4 


140 


62.2 


102. 1 


88.7 


190 


84.9 


139- 1 


121. 


141 


62.7 


102.8 


89-3 


191 


85-4 


139-9 


121.7 


142 


63-1 


103-5 


90.0 


192 


85-9 


140.6 


122.3 


143 


63.6 


104.3 


90.6 


193 


86.3 


141. 4 


123.0 


144 


64.0 


105.0 


91-3 


194 


86.8 


142. 1 


123.6 


145 


64-5 


105.8 


91.9 


195 


87.2 


142.8 


124.3 


146 


64.9 


106.5 


92.6 


196 


87.7 


143-6 


124.9 


147 


65-4 


107.2 


93-2 


197 


88.1 


144-3 


125.6 


148 


6s. 8 


108.0 


93-9 


198 


88.6 


145. 1 


126.2 


149 


66.3 


108.7 


94-5 


199 


89.0 


145-8 


126.9 


150 


66.8 


109.5 


95-2 


200 


89-5 


146.6 


127.5 


151 


67-3 


no. 2 


95-8 


201 


89.9 


147-3 


128.2 


152 


67.7 


III.O 


96-5 


202 


90.4 


148. 1 


128.8 


153 


68.3 


III. 7 


97-1 


203 


90.8 


148.8 


129.5 


154 


68.7 


112. 4 


97-8 


204 


91-3 


149.6 


130. 1 


155 


69.2 


113. 2 


98.4 


205 


91.7 


150-3 


130.8 


156 


69.6 


113-9 


99-1 


206 


92.2 


151. 1 


131-5 


157 


70.0 


114. 7 


99-7 


207 


92.6 


151. 8 


132. 1 


158 


70.5 


115. 4 


100.4 


208 


93-1 


152-5 


132.8 


159 


70.9 


116. 1 


lOI.O 


209 


93-5 


153-3 


133-4 


160 


71-3 


116. 9 


101.7 


210 


94.0 


154-1 


134- 1 


161 


71.8 


117. 6 


102.3 


211 


94-4 


154.8 


134-7 


162 


72-3 


118. 4 


103.0 


212 


94-9 


155-6 


135-4 


163 


72.7 


119. 1 


103.6 


213 


95-3 


156-3 


136.0 


164 


73-2 


119. 9 


104.3 


214 


95-8 


157 -I 


136.7 


16^ 


73-6 


120.6 


104.9 


215 


96-3 


157-8 


137-3 


166 


74-1 


121. 4 


105.6 


216 


96.7 


158.6 


138.0 


167 


74-5 


122. 1 


106.2 


217 


97-2 


159-3 


138.6 


168 


74-9 


122.9 


106.9 


218 


97-6 


160.0 


139-3 


169 


75-4 


123.6 


107.5 


219 


98.1 


160.8 


139-9 


170 


75-8 


124.4 


108.2 


220 


98.6 


161. 5 


140.6 


171 


76.3 


125. 1 


108.8 


211 


99-0 


162.3 


141. 2 


172 


76.8 


125.8 


109.5 


222 


99-5 


163.0 


141. 9 


173 


77-3 


126.6 


no. I 


223 


99-9 


163.7 


142.5 


174 


77-7 


127.3 


no. 8 


224 


100.4 


164.5 


143-2 


175 


78.2 


128. 1 


III. 4 


225 


100.9 


165-3 


143-8 


176 


78.6 


128.8 


112. 


226 


101.3 


166.0 


144-S 


177 


79-1 


129-5 


112. 6 


227 


101.8 


166.8 


145 -I 


178 


79-5 


130-3 


^-^3-2, 


228 


102.2 


167.5 


145.8 


, 179 


80.0 


131. 


113-9 


229 


102.7 


168.3 


146.4 



SUGAR AND SACCHARINE PRODUCTS. 



597 



defren'S table for the determination of dextrose, maltose, 

AND LACTOSE— (Co«c/«(^J). 



Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


Milligrams 
of Cupric 


Milligrams 


Milligrams 


Milligrams 


of Dextrose. 


of Maltose. 


of Lactose. 


Oxide. 


of Dextrose. 


of Maltose. 


of Lactose. 


230 


103. 1 


169. 1 


147.0 


280 


126. 1 


206.8 


179.6 


231 


103.6 


169.8 


147-7 


281 


126.5 


207-5 


180.2 


232 


104.0 


170.6 


148.3 


282 


127.0 


208.3 


180.9 


233 


104.5 


171-3 


149.0 


283 


127.4 


209.0 


181. 5 


234 


105.0 


172. 1 


149.6 


284 


127.9 


209.8 


182.2 


235 


105.4 


172.8 


150-3 


285 


128.3 


210.5 


182.9 


236 


105.9 


173-6 


150.9 


286 


128.8 


211. 3 


183.6 


237 


106.3 


174-3 


151. 6 


287 


129.3 


212. 1 


184.2 


238 


106.8 


175-I 


152.2 


288 


129.7 


212.8 


184.9 


239 


107.2 


175-8 


152-9 


289 


130.2 


213.6 


185.6 


240 


107.7 


176.6 


153-5 


290 


130.6 


214-3 


186.2 


241 


108. 1 


177-3 


154-2 


291 


131. 1 


215. 1 


186.9 


242 


108.6 


178. 1 


154-8 


292 


13I-5 


215-9 


187.6 


243 


109.0 


178.8 


155-5 


293 


132.0 


216.6 


188.2 


244 


109.5 


179.6 


156. 1 


294 


132-5 


217.4 


188.9 


245 


109.9 


180.3 


156.8 


295 


133-0 


218.2 


189.5 


246 


no. 4 


181. 1 


157-4 


296 


133-4 


218.9 


190.2 


247 


no. 9 


181. 8 


158. 1 


297 


133-9 


219.7 


190.8 


248 


III. 3 


182.6 


158-7 


298 


134-3 


220.4 


191-5 


249 


III. 8 


183-3 


159-4 


299 


134.8 


221.2 


192. 1 


250 


112. 3 


184. 1 


160.0 


300 


135-3 


221.9 


192.8 


251 


112. 7 


184.8 


160.7 


301 


135-7 


222.7 


193-4 


252 


113. 2 


185-5 


161. 3 


302 


136.2 


223-5 


194. 1 


253 


II3-7 


186.3 


162.0 


303 


136.6 


224.2 


194.7 


254 


114. 1 


187. 1 


162.6 


304 


137-I 


225.0 


I9S-3 


255 


114. 6 


187.8 


T-(>i-z 


305 


137-6 


225.8 


196.0 


256 


115. 


188.6 


163.9 


306 


138.0 


226.5 


196.6 


257 


iiS-5 


189.3 


164.6 


307 


138.5 


227.3 


197-3 


258 


116. 


190. 1 


165.2 


308 


138.9 


228.1 


197.9 


259 


116. 4 


190.8 


165.9 


309 


139-4 


228.8 


198.6 


260 


116. 9 


191. 6 


166.5 


310 


139-9 


229.6 


199-3 


261 


117-3 


192.4 


167.2 


311 


140.3 


230.4 


199.9 


262 


117. 8 


193- 1 


167.8 


312 


140.8 


231. 1 


200.6 


263 


118. 3 


193-9 


168. 1 


2,-^^ 


141. 2 


231.9 


201.3 


264 


118. 7 


194.6 


169.5 


314 


141-7 


232.7 


202.0 


265 


119. 2 


195-4 


169.8 


315 


142.2 


233-4 


202.6 


266 


119. 6 


196. 1 


170.4 


316 


142.6 


234.2 


203-3 


267 


120. 1 


196.9 


171. 1 


317 


I43-I 


234-9 


203.9 


268 


120.6 


197.7 


171. 7 


318 


143.6 


235-7 


204.6 


269 


121. 


198.4 


172.4 


319 


144.0 


236.5 


205 - 3 


270 


121. 4 


199.2 


173-0 


320 


144-5 


237.2 


205.9 


271 


121. 9 


199.9 


173-7 










272 


122.4 


200.7 


174-4 










273 


122.8 


201.5 


175.0 










274 


123-5 


202.2 


175-7 










275 


123-7 


203.0 


176-3 










276 


124.2 


203.7 


177.0 










277 


124.6 


204.5 


177.6 










278 


125. 1 


205 . 2 


178-3 










279 


125.6 


206.0 


T78.0 








, 



598 FOOD INSPECTION AND ANALYSIS 

Munson and Walker Method.* — i. Preparation of Solutions and 
Asbestos. — Use the copper sulphate solution and alkaline tartate solution 
as given on page 591. Prepare the asbestos, which should be the 
amphibole variety, by first digesting with i -.t, hydrochloric acid for two or 
three days. Wash free from acid, and digest for a similar period with 
soda solution, after which treat for a few hours with hot alkaline copper 
tartrate solution of the strength employed in sugar determinations. Then 
wash the asbestos free from alkali, finally digest with nitric acid for several 
hours, and after washing free from acid, shake with water for use. In 
preparing the Gooch crucible, load it with a film of asbestos one-fourth inch 
thick, wash this thoroughly with water to remove fine particles of asbestos; 
finally wash with alcohol and ether, dry for thirty minutes at 100° C, 
cool in a desiccator and weigh. It is best to dissolve the cuprous oxide 
with nitric acid each lime after weighing, and use the same felts over and 
over again, as they improve with use. 

2. Process. — Transfer 25 cc. each of the copper and alkaline tartrate 
solutions to a 400-cc. Jena or Non-sol beaker, and add 50 cc. of reducing 
sugar solution, or, if a smaller volume of sugar solution be used, add 
water to make the final volume 100 cc. Heat the beaker upon an asbestos 
gauze over a Bunsen burner, so regulate the flame that boiling begins in 
four minutes, and continue the boiling for exactly two minutes. Keep 
the beaker covered with a watch-glass throughout the entire time of 
heating. Without diluting, filter the cuprous oxide at once on an asbestos 
felt in a porcelain Gooch crucible, using suction. W^ash the cuprous 
oxide thoroughly with water at a temperature of about 60° C, then with 
ID cc. of alcohol, and finally with 10 cc. of ether. Dry for thirty minutes 
in a water oven at 100° C, cool in a desiccator and weigh as cuprous 
oxide. 

The number of milligrams of copper reduced by a given amount of 
reducing sugar differs when sucrose is present and when it is absent. 
In the tables on pp. 599 to 607 the absence of sucrose is assumed, except 
in the two columns under invert sugar, where one for mixtures of invert 
sugar and sucrose (0.4 gram of total sugar in 50 cc. of solution), and one 
for invert sugar and sucrose when the 50 cc. of solution contains 2 grams 
of total sugar are given, in addition to the column for invert sugar 
alone. 



* Jour. Am. Chem. Soc, 28, 1906, p. 163; 29, 1907, p. 54;; U. S. Dept. Agric, Bur. 
of Chem., Bui. 107 (rev.), p. 241. 



SUGAR AND SACCHARINE PRODUCTS. 



599 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 
SUGAR, LACTOSE, AND MALTOSE. 

[Weights in milligrams.] 



o 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 





3 
















3 


o 






















CJ 
















d 










V 








a 


^- 






d 




C 


4) 


13 


^ 













-*• 






C4 

X 


•0 

•a 



3 

2 

a 

3 


o 


3 



lU 


BO 
3 
t/2 


H 


.; 


+ 


+ 


^ 


+ 


3 

o 

a 

3 




0. 
0. 





X 





C 3 


ES, 



X 


6 


d 

?! 


6 
X 


i 


o 







6 


« 


C 








6 


c 





lO 


8.9 


4.0 


4.5 


1.6 




3-8 


3-9 


4.0 


5-9 


6.2 


10 


n 


9.8 


4-5 


50 


2 . 1 




4-5 


4.6 


4.7 


6.7 


70 


II 


12 


10.7 


4-9 


5-4 


2.5 




S-i 


5-3 


S-4 


7-5 


7-9 


12 


13 


ii-S 


5-3 


5.8 


30 




5-8 


5-9 


6,1 


8.3 


8.7 


13 


»4 


12.4 


5-7 


6.3 


3-4 




6.4 


6.6 


6.8 


91 


9-5 


14 


IS 


13-3 


6.2 


6.7 


3-9 




7-1 


7-3 


7.5 


9-9 


lO. 4 


IS 


i6 


14.2 


6.6 


7.2 


4.3 




7-7 


8.0 


8.2 


10 . 6 


11.2 


x6 


17 


IS-I 


7.0 


7.6 


4.8 




8.4 


8.6 


8.8 


II .4 


12.0 


17 


i8 


16.0 


7-5 


8.1 


5-2 




9- I 


9-3 


9-5 


12.2 


12.9 


18 


•19 


16 .9 


7-9 


8.5 


5.7 




9-7 


10. 


10. 2 


130 


13-7 


19 


20 


17.8 


8.3 


8.9 


6.1 




10.4 


10.6 


10 . 9 


13-8 


14.6 


20 


ai 


18.7 


8.7 


9-4 


6.6 




1 1 . 


it-3 


II. 6 


14.6 


154 


21 


32 


195 


9.2 


9.8 


7.0 




II .7 


12.0 


12-3 


15-4 


16.2 


22 


23 


20. 4 


9.6 


10.3 


7-5 




12-3 


12.7 


130 


16.2 


17.1 


23 


24 


21.3 


10 .0 


10.7 


7-9 




I3-0 


133 


13-7 


17.0 


17.9 


24 


as 


22 . 2 


10.5 


1 1 . 2 


8.4 




13-6 


14.0 


14.4 


17.8 


18.7 


25 


a6 


23-1 


10.9 


II. 6 


8.8 




14.3 


14.7 


15. I 


18.6 


19.6 


26 


27 


24.0 


1 1. 3 


12 .0 


9-3 




15-0 


iS-3 


15-7 


19.4 


20 . 4 


27 


28 


24.9 


:i.8 


12-S 


9-7 




15-6 


16.0 


16 .4 


20. 2 


21.2 


23 


29 


25.8 


12 . 2 


12.9 


10. 2 




16.3 


16.7 


17. I 


21.0 


22 . I 


29 


30 


26.6 


12.6 


13-4 


10.7 


4.3 


16 .9 


17.4 


17.8 


21,8 


22.9 


30 


31 


27-5 


I3-I 


13.8 


1 1 . I 


4-7 


17.6 


18.0 


18. s 


22 . 6 


23-7 


31 


32 


28.4 


135 


14-3 


II. 6 


5-2 


1S.2 


18.7 


19.2 


23 -3 


24.6 


32 


3i 


293 


139 


14.7 


12.0 


5-6 


18.9 


19.4 


19.9 


24. I 


25-4 


33 


34 


30.2 


14.3 


15-2 


12. 5 


6.1 


19s 


20. I 


20 . 6 


24.9 


26 . 2 


34 


3S 


3I-I 


14.8 


IS. 6 


12.9 


6.5 


20. 2 


20.7 


21.3 


25.7 


27.1 


35 


36 


32.0 


IS-2 


16. 1 


13.4 


7.0 


20.9 


21.4 


22 .0 


26. 5 


27.9 


36 


37 


32.9 


15-6 


16. s 


13-8 


7-4 


21.5 


22.1 


22.7 


27-3 


28.7 


37 


38 


33.8 


16. 1 


16.9 


14-3 


7.9 


22 . 2 


22.8 


233 


28.1 


29.6 


38 


39 


34-6 


16. s 


17.4 


14-7 


8.4 


22.8 


234 


24 .0 


28.9 


30.4 


39 


40 


355 


16.9 


17.8 


IS-2 


8.8 


23-5 


24.1 


24.7 


29.7 


313 


40 


41 


36.4 


17.4 


18.3 


IS. 6 


9-3 


24.1 


24.8 


25-4 


30.5 


32.1 


41 


42 


37-3 


17.8 


18.7 


16.1 


9-7 


24.8 


25-4 


26.1 


31 -3 


32.9 


42 


43 


38.2 


18.2 


19.2 


16.6 


10 . 2 


25.4 


26. 1 


26.8 


32.1 


33-8 


43 


44 


39-1 


18.7 


19 .6 


17.0 


10.7 


26.1 


26.8 


27. S 


32.9 


34-6 


44 


4| 


40.0 


19. 1 


20. 1 


17. 5 


1 1 . I 


26.8 


27. S 


28.2 


33-7 


35-4 


4S 


46 


40.9 


19.6 


20. s 


17.9 


II. 6 


27.4 


28.1 


28.8 


34-4 


36.3 


46 


47 


41.7 


20.0 


21 .0 


18.4 


12.0 


28.1 


28.8 


295 


35-2 


37-1 


47 


48 


42 . 6 


20. 4 


21.4 


18.8 


12. S 


28.7 


29s 


30.2 


36.0 


37.9 


48 


49 


43 -S 


20.9 


21.9 


19-3 


12.9 


29.4 


30.1 


30-9 


36.8 


38.8 


49 


SO 


44.4 


21.3 


22.3 


19.7 


134 


30.0 


30.8 


31.6 


37.6 


39.6 


50 


SI 


45-3 


21.7 


22.8 


20.2 


13-9 


30 -7 


31-5 


32.3 


38.4 


40.4 


51 


52 


46. 2 


22 . 2 


23.2 


20.7 


14.3 


31-3 


32.1 


330 


39-2 


41.3 


52 


S3 


47-1 


22 .6 


23-7 


21 . 1 


14.8 


32.0 


32.8 


33.6 


40.0 


42. I 


S3 


54 


48.0 


23 .0 


24.1 


21.6 


IS-2 


32.6 


33-5 


34-3 


40.8 


42.9 


54 


SS 


48.9 


235 


24.6 


22.0 


157 


33-3 


34-1 


350 


41 . 6 


43-8 


55 


S6 


49-7 


239 


25.0 


22.5 


16.2 


33-9 


34.8 


3S-7 


42.4 


44.6 


56 


57 


50.6 


24-3 


2S-5 


22.9 


16.6 


34-6 


35-5 


36.4 


43-2 


45-4 


57 


S8 


Si-5 


24.8 


25-9 


23-4 


17. I 


35-2 


36.1 


37. I 


44.0 


46.3 


58 


59 


52.4 


25.2 


26. 4 


23.9 


17. 5 


35-9 


36.8 


37-7 


44.8 


471 


59 


60 


53-3 


25.6 


26.8 


24-3 


18.0 


36. 5 


37.5 


38.4 


45-6 


48.0 


60 


61 


54-2 


26.1 


27.3 


24.8 


18. s 


37-2 


38.2 


39.1 


46.3 


48.8 


6r 


62 


SS-i 


26. S 


27.7 


25.2 


18.9 


37.8 


38.8 


39.8 


47.1 


49-6 


62 


^3 


56.0 


27.0 


28.2 


25-7 


19.4 


38. s 


395 


40. S 


47-9 


SO. 5 


63 


64 


S6.8 


27.4 


28.6 


26.2 


19.8 


39-2 


40. 2 


41.2 


48.7 


513 


64 



boo 



FOOD INSPECTION yIND ANALYSIS. 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MKUTOSY.— {Continued). 

[Weights in milligrams.] 



o 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 


d 


S 






















3 


o 







































d 










o 








"a 


_ 




d 




d 


a 


-0 


3 

















K 




X 


"2 


O 
1/i 


6 


M 
3 
CO 




^ 


+ 


+ 


^ 


+ 





3 
p 




I 


u< 




E =3 


q 


6 

?! 





d 


d 


3 



a 

3 


a 



(U 


> 


O' 3 
^--« 


S 3 
0^ 


1 


K 


X 


ffi 


X 


3 


O 





D 




d 


N 


CJ 





<5 


u 





u 


65 


57-7 


27.8 


29.1 


26.6 


20.3 


39.8 


40.9 


41 .9 


49-5 


52.1 


6S 


66 


58.6 


28.3 


29. S 


27.1 


20.8 


40.5 


41 . 6 


42.6 


50 . 3 


53.0 


66 


67 


59-5 


28.7 


30.0 


27. 5 


21.2 


41 . 1 


42.2 


43.3 


51 .1 


53.8 


67 


68 


60. 4 


29.2 


30.4 


28.0 


21.7 


41.8 


42.9 


44.0 


51.9 


54.6 


68 


69 


61.3 


29 . 6 


30.9 


28.5 


22 . 2 


42.5 


43.6 


44.7 


52.7 


55. 5 


69 


70 


62.2 


30.0 


31-3 


28.9 


22.6 


43. 1 


44.3 


45-4 


53.5 


56.3 


70 


71 


63.1 


30. 5 


31-8 


29.4 


23.1 


43.8 


44.9 


46.1 


54.3 


57. I 


71 


72 


64 .0 


30.9 


32.3 


29.8 


23-5 


44-4 


45.6 


46.8 


55-1 


58.0 


72 


73 


64.8 


31-4 


327 


30.^ 


24.0 


45- I 


46.3 


47.5 


55-9 


58.8 


73 


74 


65-7 


31.8 


33-2 


30.8 


24. 5 


45-7 


47.0 


48.2 


56.7 


59.6 


74 


75 


66.6 


32.2 


33-6 


31.2 


24.9 


46.4 


47.6 


48.8 


57.5 


60. 5 


75 


76 


67.5 


32.7 


34-1 


31 .7 


25-4 


47.0 


48.3 


49. S 


58.2 


61.3 


76 


77 


68.4 


33.1 


34. 5 


32.1 


25.9 


47.7 


49.0 


50.2 


59.0 


62 . 1 


77 


78 


69.3 


33.6 


35 


32.6 


26.3 


48.4 


49.6 


50.9 


59.8 


63.0 


78 


79 


70.2 


340 


35-4 


33-1 


26.8 


49 


50.3 


51.6 


60.6 


63.8 


79 


80 


71. 1 


34.4 


35-9 


33-5 


27.3 


49.7 


51.0 


52.3 


61.4 


64.6 


80 


81 


71 .9 


34-9 


36.3 


34.0 


27.7 


SO. 3 


5T.6 


53.0 


62.2 


65.5 


81 


82 


72.8 


35-3 


36.8 


34-5 


28.2 


51.0 


52.3 


53 . 7 


63.0 


66.3 


82 


83 


73-7 


35.8 


37.3 


34.9 


28.6 


51.6 


53.0 


54.4 


63.8 


67.1 


83 


84 


74.6 


36.2 


37-7 


35-4 


29.1 


52.3 


53.7 


55.0 


64.6 


68.0 


84 


85 


75-5 


36.7 


38.2 


35.8 


29.6 


52.9 


54-3 


55-7 


65.4 


68.8 


SS 


86 


76.4 


37-1 


38.6 


36.3 


30.0 


53.6 


55. 


56.4 


66.2 


69.7 


86 


87 


77-3 


37-5 


39-1 


36.8 


30.5 


54-3 


55-7 


57 ■ I 


67 .0 


70.5 


87 


88 


78.2 


38.0 


39-5 


37-2 


310 


54-9 


56.4 


57.8 


67.8 


71.3 


88 


89 


79.1 


38.4 


40.0 


37-7 


31-4 


55-6 


57.0 


58.5 


68.5 


72.2 


89 


90 


79-9 


38.9 


40.4 


38.2 


31.9 


56.2 


57.7 


59.2 


69.3 


73.0 


90 


91 


80.8 


39-3 


40.9 


38.6 


32.4 


56.9 


58.4 


59.9 


70.1 


73.8 


91 


92 


81.7 


39.8 


41 .4 


39-1 


32.8 


57.5 


59.0 


60.6 


70.9 


74.7 


92 


93 


82.6 


40 . 2 


41 .8 


39-6 


33.3 


58.2 


59.7 


61.3 


71 -7 


75.5 


93 


94 


83-5 


40.6 


42.3 


40.0 


33.8 


58.8 


60.0 


61 . 9 


72.5 


76.3 


94 


95 


84.4 


41 .1 


42.7 


40. 5 


34-2 


59.5 


61. I 


62.6 


73.3 


77.2 


95 


96 


85.3 


41.5 


43-2 


41.0 


34.7 


60. 2 


61.7 


63.3 


74.1 


78.0 


96 


97 


86.2 


42 . 


43-7 


41 .4 


35-2 


60.8 


62 .4 


64.0 


74.9 


78.8 


97 


98 


87.1 


42.4 


44. I 


41.9 


35.6 


61.5 


63.1 


64.7 


75.7 


79-7 


98 


99 


87.9 


42.9 


44-6 


42.3 


36.1 


62.1 


63.8 


65.4 


76. S 


80. 5 


99 


100 


88.8 


43.3 


45-0 


42.8 


36.6 


62.8 


64.4 


66.1 


77-3 


81.3 


100 


lOI 


89.7 


43.8 


45-5 


43-3 


37.0 


63.4 


65.1 


66.8 


78.1 


82.2 


lOI 


102 


90 . 6 


44.2 


46.0 


43-8 


37. S 


64. I 


65.8 


67.5 


78.8 


83.0 


102 


103 


91 .5 


44-7 


46.4 


44.2 


38.0 


64. 7 


66.4 


68. I 


79.6 


83.8 


103 


I04 


92.4 


45- I 


46.9 


44.7 


38.5 


65.4 


67.1 


68.8 


80.4 


84.7 


104 


los 


93-3 


45-5 


47.3 


45.2 


38.9 


66.1 


67.8 


69.3 


81.2 


85.5 


loS 


106 


94.2 


46 . 


47.8 


45-6 


39.4 


66.7 


68.5 


70.2 


82.0 


86.3 


106 


107 


95 -o 


46.4 


48.3 


46 . I 


39-9 


67.4 


69 . I 


70.9 


82.8 


87.2 


107 


108 


95.9 


46.9 


48.7 


46.6 


40.3 


68.0 


69.8 


71.6 


83.6 


88.0 


108 


109 


96.8 


47-3 


49.2 


47.0 


40. 8 


68.7 


70.5 


72.3 


84.4 


88.8 


109 


no 


97-7 


47-8 


49-6 


47. 5 


41.3 


69.3 


7 I . I 


73.0 


85.2 


89.7 


no 


III 


98.6 


48.2 


50.1 


48.0 


41 -7 


70.0 


71.8 


73.6 


86.0 


90.5 


III 


112 


99. S 


48.7 


50.6 


48.4 


42.2 


70.6 


72.5 


74.3 


86.8 


91.3 


112 


113 


100. 4 


49. I 


5I-0 


48.9 


42.7 


71.3 


73- I 


75.0 


87.6 


92,2 


115 


114 


loi .3 


49-6 


515 


49.4 


43-2 


71-9 


73-8 


75.7 


88.4 


93.0 


114 


115 


102 . 2 


SO.o 


51.9 


49.8 


43-6 


72.6 


74-5 


76.4 


89.2 


93.9 


115 


116 


103.0 


SO. 5 


52.4 


50.3 


44- 1 


73-2 


75.2 


77.1 


90.0 


94-7 


116 


117 


103.9 


50.9 


52.9 


50.8 


44-6 


73-9 


75.8 


77-8 


90.7 


95-5 


117 


118 


104. 8 


51.4 


53-3 


51.2 


450 


74-5 


76.5 


78.5 


91.5 


96.4 


118 


119 


105.7 


SI. 8 


53.8 


51.7 


45.5 


75.2 


77.2 


79. I 


92-3 


97.2 


119 



SUGAH AND SACCHARINE PRODUCTS 



6oi 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND yiMfTO^Y.— {Continued). 

[Weights in milligrams.] 



o 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 


g 


3 
















^ 


o 







































d 










o 








■^ 


^_ 






C 




d 


u 


"2 
O 


3 





M 
3 




1 




+ 


+ 




+ 


•a 



tf) 







M 


t/3 •! 


3 


^ 


« 


^ 


^ 




3 
P 


u 





u 


2 "i 


la 





q 


% 





c 


3 




D. 


a 




Q 


> 

C 


3 
d 


2 3 

0"3 


c5 


c5 


6 


c 


6 


c 
3 



I20 


106 . 6 


52-3 


54.3 


52.2 


46.0 


75-8 


77-8 


79.8 


93.1 


98.0 


120 


121 


107-5 


52-7 


54-7 


52.7 


46.5 


76. 5 


78.5 


80.5 


93-9 


98.9 


121 


122 


108. 4 


53-2 


55-2 


53.1 


46.9 


77-1 


79-2 


81.2 


94-7 


99-7 


122 


123 


109 -3 


53-6 


SS-7 


53.6 


47.4 


77-8 


79-9 


81 .9 


95.5 


100.5 


123 


124 


no. I 


54-1 


56.1 


54.1 


47-9 


78. 5 


80.5 


82.6 


96.3 


lOI . 4 


124 


I2S 


III .0 


54-5 


S6.6 


54-5 


48.3 


791 


81.2 


83.3 


97.1 


102 . 2 


I2S 


126 


III .9 


550 


57 


55-0 


48.8 


79.8 


81 .9 


84.0 


97.9 


103.0 


126 


127 


112. 8 


55-4 


57-5 


55-5 


49-3 


80.4 


82.5 


84.7 


98.7 


1039 


127 


128 


113-7 


SS-9 


58.0 


55-9 


49.8 


81. I 


83.2 


85.4 


99.4 


104.7 


128 


129 


114-6 


56.3 


58.4 


56.4 


50.2 


81.7 


83.9 


86.0 


100. 2 


105.5 


129 


130 


"5-5 


56.8 


58.9 


56.9 


50.7 


82.4 


84.6 


86.7 


loi .0 


106 . 4 


130 


131 


116.4 


57-2 


59.4 


57-4 


51.2 


83.1 


85.2 


87-4 


loi .8 


107 . 2 


131 


132 


117-3 


57-7 


59.8 


57-8 


51.7 


83.7 


85.9 


88.1 


102 .6 


108.0 


132 


133 


118. 1 


58.1 


60.3 


58.3 


52.1 


84.4 


86.6 


88.8 


103.4 


108. 9 


133 


134 


119. 


S8.6 


60.8 


58-8 


52.6 


85-0 


87.3 


89.5 


104. 2 


109.7 


134 


135 


119. 9 


590 


61.2 


59-3 


53-1 


85.7 


87.9 


90. 2 


105 .0 


1 10 . 5 


13s 


136 


120.8 


59.5 


61.7 


59-7 


53-6 


86.3 


88.6 


90.9 


105.8 


1 1 1 .4 


136 


137 


121 . 7 


60.0 


62 .2 


60 . 2 


S4.0 


87.0 


89-3 


91 .6 


106 . 6 


112.2 


137 


138 


122 .6 


60. 4 


62.6 


60. 7 


54.5 


87-7 


90 .0 


92.3 


107.4 


113.0 


138 


139 


123. S 


60.9 


63.1 


61.2 


55.0 


88.3 


90.6 


93-0 


108.2 


113. 9 


139 


140 


124.4 


61.3 


63.6 


61.6 


55-5 


89.0 


91-3 


93-6 


109 .0 


114.7 


140 


141 


125.2 


61.8 


64.0 


62.1 


55.9 


89.6 


92 .0 


94-3 


109.8 


115. 5 


141 


142 


126. 1 


62 .2 


64.5 


62.6 


56.4 


90.3 


92.6 


95-0 


110.5 


116. 4 


142 


143 


127.0 


62.7 


65.0 


63.1 


56.9 


90.9 


93-3 


95-7 


III. 3 


117.2 


143 


144 


127.9 


63.1 


65.4 


63-S 


57.4 


91 .6 


940 


96.4 


1 12 . 1 


118.0 


144 


I4S 


128.8 


63-6 


65.9 


64.0 


57.8 


92.2 


94-7 


97-r 


112.9 


118.9 


145 


146 


129.7 


64 .0 


66.4 


64-5 


58.3 


92.9 


95-3 


97-8 


113.7 


119.7 


146 


147 


130.6 


64.5 


66.9 


65-0 


58-8 


93-5 


96.0 


98.4 


114.5 


120.5 


147 


148 


131-S 


65.0 


^7.3 


65-4 


59-3 


94-2 


96.7 


99.1 


115.3 


121 . 4 


148 


149 


132.4 


65-4 


67.8 


659 


59.7 


94-8 


97.3 


99-8 


116. 1 


122 . 2 


149 


150 


133-2 


65-9 


68.3 


66.4 


60.2 


95-5 


98.0 


100. 5 


1 16 . 9 


123.0 


150 


151 


I34-I 


66.3 


68.7 


66.9 


60.7 


96. 2 


98.7 


lOI . 2 


117. 7 


123.9 


151 


152 


I35-0 


66.8 


69. 2 


67.3 


61.2 


96.8 


99-3 


loi . 9 


118. s 


124.7 


152 


153 


I3S-9 


67.2 


69.7 


67.8 


61.7 


97-5 


TOO . 


102 .6 


119. 3 


125.5 


153 


154 


136-8 


67-7 


70.1 


68.3 


62.1 


98. I 


100. 7 


103-3 


120.0 


126. 4 


154 


15s 


137-7 


68.2 


70.6 


68.8 


62.6 


98.8 


lOI . 4 


104.0 


120.8 


127.2 


15s 


IS6 


138.6 


68.6 


71. 1 


69 . 2 


63.1 


99-4 


102 .0 


104.7 


12 1 . 6 


128.0 


156 


157 


139-5 


69. 1 


71.6 


69.7 


63.6 


100. I 


102 . 7 


105-3 


122.4 


128.9 


157 


158 


140.3 


69-5 


72.0 


70.2 


64. 1 


100. 7 


103.4 


106.0 


123.2 


129. 7 


IS8 


159 


141 . 2 


70.0 


72.5 


70.7 


64. 5 


lOI .4 


104. I 


106. 7 


124.0 


130.5 


159 


160 


142. 1 


70.4 


73.0 


71.2 


65.0 


102 .0 


104.7 


107.4 


124.8 


131-4 


160 


161 


I43-0 


70.9 


73.4 


71.6 


65. 5 


102 . 7 


I05-4 


108. 1 


125.6 


132.2 


161 


162 


143-9 


71.4 


73.9 


72.1 


66.0 


103 -4 


106. 1 


108.8 


126.4 


1330 


162 


163 


144-8 


71.8 


74-4 


72.6 


66.5 


104 .0 


106. 7 


109-5 


127.2 


133-9 


163 


164 


145-7 


72.3 


74.9 


73 I 


66.9 


104.7 


107.4 


no. 2 


128.0 


134-7 


164 


J6s 


146.6 


72.8 


75-3 


73-6 


67.4 


105.3 


108. 1 


no. 9 


128.8 


1355 


i6s 


166 


147-5 


73.2 


75.8 


74.0 


67.9 


106 .0 


108.8 


in. 5 


129.6 


136.4 


166 


167 


148-3 


73-7 


76.3 


74-5 


68.4 


106. 6 


109.4 


112.2 


130.3 


137-2 


167 


168 


149.2 


74-1 


76.8 


75-0 


68.9 


107.3 


no. I 


112.9 


131.1 


133.0 


168 


169 


150-1 


74-6 


77.2 


75-5 


69-3 


107.9 


110.8 


113.6 


131. 9 


138.9 


169 


170 


151 -o 


75-1 


77.7 


76.0 


69-8 


108.6 


1 1 1 . 4 


n4.3 


132.7 


139.7 


170 


171 


151.9 


75-5 


78.2 


76.4 


70.3 


109. 2 


1 12 . 1 


115.0 


133.5 


140.5 


171 


172 


152.8 


76.0 


78.7 


76.9 


70.8 


109.9 


112 .8 


iiS-7 


134-3 


141.4 


17* 


173 


153-7 


76.4 


79- I 


77-4 


71-3 


no. 5 


II3-5 


116. 4 


135.1 


142 . 2 


173 


174 


154.6 


76.9 


79.6 


77-9 


71 -7 


1 1 1 . 2 

1 


114. I 


117.1 


135.9 


143.0 


174 



602 



FOOD INSPECTION AND /IN A LYSIS. 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MMJTOS^— {Continued). 

[Weights in milligrams.] 



o 








Invert Sugar 
and Sucrose. 


Lactose. 




Maltose. 





J 


cij 






d 


d 




d 


3 


0) 


■p. 

O 

in 
3 


3 


u 


i 









"5 



c5 


+ 

6 


+ 

6 





+ 

6 


•0 

3 





(U 


u 


t 




(3 M 


S3 


?! 


a 


n 


s 


2 


a 

;3 


a 
a 



I 


5; 


2 3 


w 


w 


m 


W 


W 


3 


O 








6 


" 


d 


6 


c5 


6 


6 





175 


iSS-S 


77-4 


80.1 


78.4 


72.2 


III .9 


114.8 


117. 7 


136-7 


143-9 


17s 


176 


1563 


77-8 


80.6 


78.8 


72.7 


112.5 


iiS-5 


118.4 


137-5 


144.7 


176 


177 


157-2 


78.3 


81.0 


79-3 


73-2 


113-2 


1 16. 1 


119.1 


138-3 


145-5 


177 


178 


158.1 


78-8 


81.5 


79-8 


73-7 


113.8 


116. 8 


119.8 


139.1 


146.4 


178 


179 


159.0 


79.2 


82.0 


80.3 


74.2 


114-5 


117-5 


120. s 


139-8 


147.2 


179 


180 


1599 


79-7 


82. s 


80.8 


74-6 


iiS-i 


118.2 


121 . 2 


140.6 


148.0 


180 


181 


160.8 


80.1 


82.9 


81.3 


75-1 


115.8 


118. 8 


121 .9 


141-4 


148.9 


181 


182 


161 . 7 


80.6 


83-4 


81.7 


75.6 


116.5 


119-5 


122.6 


142 . 2 


149-7 


182 


183 


162 .6 


81.1 


83-9 


82.2 


76.1 


117.1 


120. 2 


123.3 


143.0 


150-S 


183 


184 


163.4 


81.5 


84-4 


82.7 


76.6 


117.8 


120. 9 


123-9 


143-8 


151. 4 


184 


i8s 


164.3 


82.0 


84-9 


83.2 


77.1 


118.4 


121.5 


124.6 


144.6 


152.2 


18s 


186 


165.2 


82. s 


85.3 


83.7 


77-6 


119. 1 


122 .2 


125-3 


145-4 


153.0 


186 


187 


166. 1 


82.9 


85.8 


84.2 


78.0 


119. 7 


122.9 


126.0 


146 . 2 


153. 9 


187 


188 


167 .0 


83-4 


86.3 


84.6 


78.5 


120.4 


123.5 


126. 7 


147.0 


154.7 


188 


189 


167.9 


83-9 


86.8 


85.1 


79.0 


121 .0 


124 . 2 


127.4 


147-8 


155-5 


189 


190 


168.8 


84-3 


87.2 


85.6 


79-5 


121 . 7 


124.9 


128. 1 


148.6 


156.4 


190 


191 


169.7 


84.8 


87.7 


86.1 


80.0 


122.3 


125-5 


128.8 


149-3 


157-2 


191 


192 


170. 5 


85-3 


88.2 


86.6 


80,5 


123.0 


126. 2 


129-5 


150. I 


158.0 


192 


193 


171 .4 


8s -7 


88.7 


87.1 


81.0 


123.6 


126.9 


130. I 


150.9 


158-9 


193 


194 


172-3 


86.2 


89.2 


87.6 


81.4 


124-3 


127.6 


130.8 


151-7 


159-7 


194 


19s 


173-2 


86.7 


89.6 


88.0 


81.9 


125.0 


128.2 


131-5 


152-5 


160. 5 


195 


196 


174.1 


87.1 


90. 1 


88.5 


82.4 


125.6 


128.9 


132 .2 


153-3 


161 .4 


196 


197 


175-0 


87.6 


90.6 


89.0 


82.9 


126.3 


129.6 


132.9 


154-1 


162 . 2 


197 


198 


175-9 


88.1 


91 .1 


89 -5 


83-4 


126.9 


130.3 


133-6 


154-9 


163.0 


198 


199 


176.8 


88.5 


91 . 6 


90 . 


83-9 


127 .6 


130.9 


134-3 


155-7 


163.9 


199 


200 


177.7 


89.0 


' 92 .0 


90. 5 


84-4 


128.2 


131.6 


135-0 


156.5 


164.7 


200 


201 


178.5 


89-5 


92-5 


91 .0 


84.8 


128.9 


132.3 


135-7 


157-3 


165-5 


2or 


202 


179-4 


89.9 


93 


91-4 


8S-3 


129-5 


132.9 


136.3 


158.1 


166.4 


202 


203 


180.3 


90.4 


93-5 


91-9 


85-8 


130.2 


133.6 


1370 


158.8 


167 . 2 


203 


204 


181. 2 


90.9 


940 


92.4 


86.3 


130.8 


134.3 


137.7 


159-6 


168.0 


204 


20s 


1 82. 1 


91.4 


94-5 


92.9 


86.8 


I3I-5 


135.0 


138.4 


160. 4 


168.9 


20s 


206 


183.0 


91.8 


94-9 


93-4 


87-3 


132.1 


135.6 


139-1 


161 .2 


169.7 


206 


207 


183-9 


92.3 


95-4 


93-9 


87.8 


132.8 


136.3 


139-8 


162 .0 


170.5 


207 


208 


184.8 


92.8 


95-9 


94-4 


88.3 


133-4 


137-0 


140.5 


162.8 


171-4 


208 


aog 


185.6 


93.2 


96.4 


94-9 


88.8 


134-1 


137-6 


141 . 2 


163.6 


172.2 


209 


210 


186. 5 


93.7 


96.9 


95-4 


89.2 


134-8 


138-3 


141-9 


164.4 


1730 


210 


211 


187.4 


94.2 


97-4 


95-8 


89.7 


135-4 


139-0 


142 -5 


165 . 2 


173-8 


211 


212 


188.3 


94-6 


97-8 


96-3 


90.2 


136.1 


139-6 


143-2 


166.0 


174-7 


212 


213 


189.2 


95-1 


98-3 


96.8 


90.7 


136.7 


140.3 


143-9 


166.8 


175-5 


213 


214 


190. 1 


95-6 


98.8 


97-3 


91 .2 


137-4 


141.0 


144-6 


167.5 


176.4 


214 


215 


191 .0 


96. 1 


99-3 


97-8 


91.7 


138-0 


141-7 


145-3 


168.3 


177-2 


21S 


216 


191. 9 


96.5 


99-8 


98.3 


92.2 


138-7 


142.3 


146 .0 


169. 1 


178.0 


216 


217 


192.8 


97.0 


100.3 


98.8 


92.7 


139.3 


143.0 


146.7 


169.9 


178.9 


217 


218 


193-6 


97-5 


100.8 


99-3 


93-2 


140.0 


143.7 


147.3 


170.7 


179-7 


218 


219 


1 94 -5 


98.0 


loi .2 


99.8 


93-7 


140.6 


144.3 


148.0 


171-S 


180. S 


219 


220 


195-4 


98.4 


lOI . 7 


100.3 


94.2 


141. 3 


145.0 


148.7 


172.3 


181.4 


220 


221 


^96. 3 


98.9 


102 . 2 


100.8 


94.7 


141.9 


145-7 


149.4 


173.1 


182.2 


221 


222 


197-2 


99-4 


102 . 7 


lOI .2 


95.1 


142 .6 


146.3 


150.1 


173.9 


183.0 


222 


223 


198. I 


99-9 


103.2 


101 . 7 


95-6 


143-2 


147-0 


150.8 


174-7 


183-9 


223 


224 


199-0 


100.3 


103 -7 


102 .2 


96. 1 


143.9 


147.7 


151-5 


175-5 


184-7 


224 


22s 


199 9 


100.8 


104. 2 


102 . 7 


96.6 


144.6 


148.4 


152.2 


176.2 


185-S 


22s 


226 


200. 7 


101.3 


104.6 


103.2 


97 I 


145-2 


149.0 


152-9 


177-0 


186.4 


226 


227 


201 .6 


IOI.8 


105.1 


103 -7 


97-6 


145.9 


149.7 


IS3-6 


177-8 


187.2 


227 


228 . 


202.5 


102 . 2 


105.6 


104 . 2 


98.1 


146.5 


150.4 


154-2 


178.6 


188.0 


228 


229 


203.4 


102 . 7 


106. I 


104.7 


98.6 


147.2 


151-1 


154-9 


179.4 


188.8 


229 



SUGAR AND SACCHARINE PRODUCTS. 



603 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MALTOSE— (CoK/j/zwerf). 

[Weights in milligrams.] 



19 








Invert Sugar 
and Sucrose 




Lactose. 




Maltose. 





^1 








d 








3 




•a 
'S 




a 
3 



9' 


u 

CI 

a. 
a 




6 
1 
Q 


u 

DO 

u 

> 

106 . 6 


Is 



3 

d 


13 

2 3 


6 

S! 


4- 

6 



d 

+ 

6 
fi 

c 


6 
X 


d 

+ 
6 

6 


4) 
">< 

3 
fg 

' a 

3 



230 


204.3 


103.2 


105.2 


99-1 


147.8 


151. 7 


155.6 


180.2 


189.7 


230 


231 


205 . 2 


103 -7 


107 . I 


105-7 


99-6 


148.5 


152-4 


156.3 


181. 


190.5 


231 


232 


206. 1 


104. I 


107 . 6 


106. 2 


100. 1 


149.1 


I53-I 


157.0 


181. 8 


191.3 


232 


233 


207 .0 


104 . 6 


108. I 


106 . 7 


100 . 6 


149-8 


153-7 


157.7 


182.6 


192 .2 


233 


234 


207.9 


105 . I 


108.6 


107 . 2 


lOI . I 


150-5 


154-4 


158.4 


183.4 


193.0 


234 


23s 


208.7 


105.6 


109 . I 


107.7 


loi . 6 


151-1 


155-1 


159. 1 


184.2 


193.8 


235 


236 


209.6 


106 .0 


I09S 


108.2 


102 . 1 


151.8 


155.8 


159.7 


184.9 


194.7 


236 


237 


210.5 


106.5 


IIO.O 


108.7 


102 .6 


152.4 


156.4 


160 . 4 


185.7 


195.5 


237 


238 


211 . 4 


107 .0 


no. 5 


109. 2 


103. 1 


I S3 -I 


157. 1 


161 . 1 


186. 5 


196.3 


238 


239 


212.3 


I07-S 


1 1 1 .0 


109 . 6 


103.5 


153-7 


157.8 


161.8 


187.3 


197.2 


239 


240 


213.2 


108.0 


III. 5 


1 10. 1 


104.0 


154.4 


158.4 


162.5 


188.1 


198.0 


240 


241 


214. 1 


108. 4 


1 12 .0 


no. 6 


104. s 


155.0 


159. I 


163.2 


188.9 


198.8 


241 


242 


215.0 


108. 9 


112. 5 


in . I 


105.0 


155.7 


159-8 


163.9 


189.7 


199.7 


242 


243 


215.8 


109.4 


113. 


I II .6 


105.5 


156.3 


160. 5 


164.6 


190.5 


200.5 


243 


244 


216.7 


109.9 


II3-S 


112 . 1 


106 .0 


157.0 


161 . I 


165.3 


191. 3 


201.3 


244 


24S 


217.6 


no. 4 


114. 


112.6 


106.5 


157.7 


161. 8 


166.0 


192 . 1 


202 . 2 


245 


246 


218. 5 


no. 8 


114-5 


113-1 


107 .0 


158.3 


162.5 


166.6 


192.9 


203.0 


246 


247 


219.4 


III. 3 


115 .0 


113-6 


107.5 


159.0 


163.1 


167.3 


193.6 


203.8 


247 


248 


220.3 


III. 8 


II5-4 


114- 1 


108.0 


159.6 


163.8 


168.0 


194.4 


204.7 


248 


249 


221.2 


112. 3 


iiS-9 


114. 6 


108.5 


160.3 


164.5 


168.7 


195.2 


205.5 


249 


250 


222 . 1 


112. 8 


116. 4 


115. 1 


109.0 


160. 9 


165.2 


169.4 


196.0 


206.3 


250 


251 


223 .0 


113. 2 


116. 9 


115-6 


109. 5 


161. 6 


165.8 


170 . 1 


196.8 


207 . 2 


251 


252 


223.8 


113-7 


117-4 


116. 1 


IIO.O 


162 . 2 


166. 5 


170.8 


197.6 


208.0 


252 


253 


224.7 


114. 2 


117. 9 


116.6 


110.5 


162 .9 


167 . 2 


171. 5 


198.4 


208.8 


253 


254 


225.6 


114. 7 


118. 4 


117. 1 


III .0 


163. 5 


167.9 


172 .2 


199.2 


209.7 


254 


2SS 


226.5 


115.2 


118. 9 


117 .6 


111.5 


164 . 2 


168.5 


172.8 


200.0 


210. 5 


255 


2S6 


227.4 


II5-7 


119. 4 


118. I 


112.0 


164.8 


169. 2 


173.5 


200. 8 


211.3 


256 


257 


228.3 


116. I 


119. 9 


118. 6 


112 . 5 


165. 5 


169.9 


174.2 


201 .6 


212.2 


257 


258 


229. 2 


116. 6 


120 . 4 


ng. I 


113.0 


166.2 


170.5 


174-9 


202.3 


213.0 


258 


259 


230 . 1 


117. 1 


120 . 9 


1 19.6 


II3-S 


166.8 


171.2 


175-6 


203.1 


213.8 


259 


260 


231-0 


117 .6 


121. 4 


120. 1 


114.0 


167.5 


171.9 


176-3 


203.9 


214.7 


260 


261 


231.8 


118. I 


12 I . 9 


120.6 


II4-S 


168. 1 


172. 5 


177.0 


204.7 


215.5 


261 


262 


232.7 


118. 6 


122 .4 


121 . 1 


115 .0 


168.8 


173.2 


177-7 


205 -S 


216.3 


262 


263 


233-6 


119. 


122 .9 


121 .6 


115.5 


169.4 


173.9 


178-3 


206.3 


217.2 


263 


264 


234-5 


119-5 


123.4 


122 . 1 


116. 


170. 1 


174-6 


179.0 


207. 1 


218.0 


264 


26s 


235-4 


120.0 


123-9 


122.6 


116.5 


170.7 


175-2 


179-7 


207-9 


218.8 


26s 


266 


236.3 


120 . 5 


124.4 


123. 1 


117.0 


171.4 


175-9 


180.4 


208.7 


219.7 


266 


267 


237.2 


121 .0 


124.9 


123.6 


117.5 


172 .0 


176.6 


181. 1 


209.5 


220.5 


267 


268 


238.1 


121. 5 


125-4 


124. 1 


118. 


172.7 


177.2 


181. 8 


210.3 


221.3 


26S 


269 


238.9 


122.0 


125-9 


124 .6 


118-S 


173-3 


177-9 


182. 5 


2ir .0 


223. I 


269 


270 


239.8 


122. s 


126.4 


125.1 


119. 


174.0 


178.6 


183.2 


211.8 


223.0 


270 


271 


240-7 


122.9 


126.9 


125.6 


119-5 


174-6 


179-2 


183.8 


212 .6 


223.8 


271 


272 


241 .6 


123.4 


127.4 


126.2 


120.0 


175.3 


179.9 


184.5 


213-4 


224.6 


272 


273 


242 .5 


123-9 


127-9 


126. 7 


120.6 


176.0 


180.6 


185.2 


214.2 


225.5 


273 


274 


243-4 


124.4 


128.4 


127 .2 


121 . 1 


176.6 


181.3 


185.9 


215.0 


226.3 


274 


275 


244-3 


124.9 


128.9 


127.7 


121 .6 


177-3 


181. 9 


186.6 


215.8 


227.1 


27s 


276 


245-2 


125.4 


129-4 


128.2 


122 . 1 


177.9 


182.6 


187.3 


2^.6.6 


228.0 


276 


277 


246. I 


125-9 


129-9 


128.7 


122 .6 


178.6 


183.3 


188.0 


217.4 


228.8 


277 


278 


246-9 


126.4 


130.4 


129. 2 


123.1 


179.2 


184.0 


188.7 


218.2 


229.6 


278 


279 


247-8 


126.9 


130.9 


129.7 


123.6 


179.9 


184.6 


189.4 


218.9 


230.5 


279 


280 


248-7 


127-3 


131-4 


130.2 


124. 1 


180.6 


185.3 


190. 1 


219.7 


231.3 


280 


281 


249.6 


127.8 


131-9 


130.7 


124.6 


181 .2 


186.0 


190.7 


220. s 


232.1 


28r 


282 


250.5 


128.3 


132.4 


131-2 


125.1 


181. 9 


186.6 


191.4 


221.3 


233.0 


282 


283 


251-4 


128.8 


132.9 


131-7 


125.6 


182.5 


187.3 


192. 1 


222 . 1 


233.8 


283 


284 


252.3 


129-3 


133-4 


132 .2 


126. 1 


183-2 


188.0 


192.8 


222 .9 


234.6 


284 



6o4 



FOOD INSPECTION AND ANALYSIS. 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 



SUGAR, 



LACTOSE, AND MALTOSE— (Co«/inMe<f). 
[Weights in milligrams.] 



o 


'J 

u 

a 
0. 
& 




« Dextrose. 

00 


u 

OB 

w 

u 
> 


Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 





3 
o 

<o 

I 

o 

u 

0. 

o 


*^ 


d 


0«2 


6 
r: 

X 

c 


d 
X 

+ 


c5 


d 

+ 


6 


6 
X 



+ 

6 
X 
u 


3 


V 


3 

s 

a 
3 



285 


253-2 


133-9 


132.7 


126.6 


183-8 


188.7 


193-5 


223.7 


235-5 


28s 


286 


254-0 


130.3 


134-4 


1332 


127 . I 


184-s 


189.3 


194-2 


224.5 


236.3 


286 


287 


254-9 


130.8 


134-9 


133-7 


127.6 


185.1 


190.0 


194-9 


225.3 


237-1 


287 


288 


255-8 


1 3 I - 3 


I3S-4 


134-3 


128. 1 


185.8 


190.7 


195-5 


226.1 


238.0 


288 


289 


256.7 


131-8 


135-9 


134.8 


128.6 


186.4 


191.3 


196 . 2 


226 . 9 


238.8 


289 


290 


257-6 


132.3 


136.4 


135-3 


129.2 


187. 1 


192 .0 


196.9 


227.6 


239-6 


290 


291 


258.5 


132.7 


136.9 


135-8 


129.7 


187.7 


192.7 


197-6 


228.4 


240. 5 


291 


292 


259-4 


133-2 


137-4 


136.3 


130.2 


188.4 


193.3 


198.3 


229. 2 


241 .3 


292 


293 


260.3 


133-7 


137-9 


136.8 


130.7 


189.0 


194.0 


199-0 


230 .0 


242. I 


295 


294 


261 . 2 


134.2 


138.4 


137-3 


131-2 


189.7 


194.7 


199-7 


230.8 


242.9 


294 


295 


262 .0 


134-7 


138.9 


137-8 


I3I-7 


190.3 


195.4 


200 . 4 


231 .6 


243-8 


295 


296 


262 . 9 


135-2 


139-4 


138.3 


132.2 


191 .0 


196 .0 


201 .0 


232.4 


244-6 


296 


297 


263.8 


135-7 


140.0 


138-8 


132.7 


191.7 


196.7 


201 . 7 


233.2 


245-4 


297 


298 


264.7 


136.2 


140.5 


139-4 


133-2 


192.3 


197-4 


202 . 4 


234.0 


246.3 


298 


299 


265.6 


136.7 


14: .0 


139-9 


133-7 


1930 


198.0 


203. 1 


234-8 


247-1 


299 


300 


266.5 


137-2 


141-5 


140.4 


134.2 


193 .6 


198.7 


203.8 


235-5 


247-9 


300 


301 


267.4 


137-7 


142 .0 


140.9 


134-8 


194.3 


199.4 


204-5 


236-3 


248.8 


3or 


302 


268.3 


138.2 


142.5 


141 .4 


135-3 


194-9 


200 .0 


205. 2 


237-1 


249.6 


302 


303 


269 . I 


138.7 


1430 


141 .9 


135-8 


195-6 


200. 7 


205.9 


237-9 


250.4 


303 


304 


270.0 


139-2 


143-5 


142.4 


136.3 


196 . 2 


201.4 


206 . 5 


238.7 


251-3 


304 


305 


270.9 


139-7 


144-0 


142.9 


136.8 


196.9 


202 . I 


207 . 2 


239.5 


252.1 


30.'; 


306 


271.8 


140. 2 


144-5 


143-4 


13 7-3 


197-5 


202 . 7 


207.9 


240.3 


252.9 


306 


307 


272.7 


140.7 


I45-0 


I44-0 


137.8 


198.2 


203.4 


208.6 


241 . I 


253-8 


307 


308 


273.6 


141 . 2 


145-5 


144-5 


138.3 


198.8 


204 . I 


209.3 


241 .9 


254.6 


308 


309 


274-5 


141 . 7 


146 . I 


145.0 


138.8 


199-5 


204.7 


210.0 


242.7 


255-4 


309 


310 


275-4 


142 .2 


146.6 


145-5 


139.4 


200. I 


205.4 


210. 7 


243.5 


256.3 


310 


311 


276.3 


142.7 


147. 1 


146 .0 


139.9 


200 . 8 


206 . I 


211 . 4 


244.2 


2S7-I 


311 


312 


277.1 


143-2 


147-6 


146.5 


140.4 


201 . 4 


206 . 7 


212 . 1 


245.0 


257-9 


312 


313 


278.0 


143-7 


148. I 


147.0 


140.9 


202 . 1 


207.4 


212.7 


245-8 


258.8 


313 


314 


278.9 


144-2 


148.6 


147-6 


141.4 


202.8 


208. I 


213.4 


246.6 


259-6 


314 


3IS 


279-8 


144-7 


149-1 


148. I 


141.9 


203.4 


208.8 


214. 1 


247.4 


260. 4 


31S 


316 


280.7 


145-2 


149-6 


148.6 


142.4 


204. 1 


209.4 


214.8 


248.2 


261 . 2 


316 


317 


281.6 


145-7 


150- I 


149-1 


143.0 


204.7 


2 10 . I 


215.5 


249.0 


262 . I 


317 


318 


282. 5 


146. 2 


150-7 


149-6 


143-5 


205.4 


2T0.8 


216.2 


249.8 


262 .9 


318 


319 


283.4 


146. 7 


151-2 


150. I 


144.0 


206 . 


211 .5 


216.9 


250.6 


263.7 


319 


320 


284.2 


147-2 


151-7 


150.7 


144-5 


206. 7 


212 . I 


217.6 


2513 


264. 6 


320 


321 


285.1 


147-7 


152 .2 


151-2 


145.0 


207.3 


212.8 


218.3 


252. I 


265.4 


321 


322 


286.0 


148.2 


152.7 


151-7 


145-5 


208.0 


213-5 


218.9 


252.9 


266. 2 


322 


323 


286.9 


148.7 


153-2 


152-2 


146 .0 


208.6 


214.1 


219.6 


253.7 


267 . I 


323 


324 


287.8 


149-2 


153-7 


152.7 


146 .6 


209.3 


214.8 


220.3 


254.5 


267.9 


324 


32s 


288.7 


149-7 


154.3 


153.2 


147-1 


210.0 


215-5 


221.0 


255. 3 


268.7 


32s 


326 


289.6 


150.2 


154.8 


153.8 


147-6 


210.6 


216.2 


221.7 


256. 1 


269. 6 


326 


327 


290.5 


150.7 


155.3 


154.3 


148. 1 


211 .3 


216.8 


222 . 4 


256.9 


270.4 


32.7 


328 


291 .4 


151.2 


155-8 


154.8 


148.6 


2 1 1 . 9 


217-5 


223.1 


257-7 


271.2 


328 


329 


292 . 2 


151-7 


156.3 


155.3 


149-1 


212.6 


218.2 


223.8 


258. 5 


272 . I 


329 


330 


293-1 


152-2 


156.8 


155.8 


149-7 


213.2 


218.8 


224.4 


259-3 


272.9 


330 


331 


294.0 


152.7 


157.3 


156.4 


150.2 


213-9 


2195 


225.1 


260 . 


273-7 


331 


332 


294-9 


153.2 


157.9 


156.9 


150.7 


214-5 


220. 2 


225.8 


260.8 


274.6 


332 


333 


295-8 


153-7 


158.4 


157.4 


151-2 


215.2 


220.8 


226 . 5 


261 . 6 


275.4 


333 


334 


296.7 


154-2 


158.9 


157.9 


151 -7 


215-8 


221 .5 


227 . 2 


262 . 4 


276 . 2 


334 


335 


297-6 


154-7 


159.4 


158.4 


152.3 


216.5 


222 . 2 


227.9 


263.2 


277.0 


335 


336 


298.5 


155-2 


159-9 


159.0 


152.8 


217 . I 


222 .9 


228.6 


264 . 


277.9 


336 


337 


299-3 


155-8 


160.5 


159. 5 


153-3 


217.8 


223.5 


229 . 2 


264.8 


278.7 


337 


338 


300.2 


'5^3 


161 .0 


160.0 


153-8 


218.4 


224 . 2 


229.9 


265.6 


279. 5 


338 


339 


301 .1 


156.8 


161. s 


160. s 


154.3 


219. I 


224.9 


230.6 


266 .4 


280 . 4 


339 



SUGAR AND SACCHARINE PRODUCTS. 



605 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MALTOSE— (Con/wJi^eti). 

[Weights in milligrams.] 



q 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 


q 


3 
















3 










































d 










<u 








d 


^^ 






d 




d 


0) 


C 


9" 




u 

M 
3 


1 


c4 






+ 


+ 




X 

+ 





tr 




Si 


m 


2 '^ 


z^ 


^ 




z^ 


^ 


yj 


3 
C 

a 


i 

a 

u 


e 

Q 


C 


2 «i 
d 






Si 

c 




13 

C 


d 
?i 


6 




S! 

X 
u 


3 

2 

a 
3 



340 


302.0 


157-3 


162 .0 


161 .0 


154.8 


219.8 


225.5 


231.3 


267 . 1 


281.2 


340 


341 


302.9 


IS7-8 


162 . 5 


161. 6 


155-4 


220. 4 


226. 2 


232.0 


267.9 


282.0 


341 


342 


303 -8 


158.3 


163.1 


162 . 1 


155-9 


221 . 1 


226.9 


232.7 


268.7 


282.9 


342 


343 


304-7 


158-8 


163.6 


162.6 


156.4 


221.7 


227.5 


233.4 


269.5 


283.7 


343 


344 


305-6 


159-3 


164. 1 


163. I 


156.9 


222 .4 


228.2 


234.1 


270.3 


284.5 


344 


34S 


306. s 


159-8 


164.6 


163-7 


157.5 


223.0 


228.9 


234.7 


271 . 1 


285.4 


345 


346 


307-3 


160.3 


165 . 1 


164. 2 


158.0 


223.7 


229 . 6 


235.4 


271.9 


286.2 


346 


347 


308.2 


160.8 


165-7 


164.7 


158.5 


224.3 


230.2 


236. 1 


272.7 


287.0 


347 


348 


309.1 


161 . 4 


166 . 2 


165 . 2 


159.0 


225.0 


230.9 


236.8 


273.5 


287.9 


348 


349 


310.0 


161 . 9 


166.7 


165-7 


159.5 


225.6 


231 .6 


237.5 


274.3 


288.7 


349 


J50 


310.9 


162 . 4 


167 . 2 


166.3 


160 . 1 


226.3 


232.2 


238.2 


275.0 


289.5 


350 


351 


3II-8 


162 . 9 


167.7 


166.8 


160. 6 


226.9 


232.9 


238.9 


275-8 


290.4 


351 


352 


312.7 


163.4 


168.3 


167.3 


161 . 1 


227 .6 


233.6 


239.6 


276.6 


291 . 2 


352 


353 


313-6 


163.9 


168.8 


167.8 


161. 6 


228.2 


234.2 


240. 2 


277.4 


292 .0 


353 


354 


314-4 


164.4 


169.3 


168.4 


162 . 2 


228.9 


234-9 


240.9 


278.2 


292.8 


354 


-355 


31S-3 


164.9 


169.8 


168.9 


162 . 7 


229.5 


235-6 


241 .6 


279.0 


293-7 


355 


356 


316.2 


165-4 


170.4 


169.4 


163.2 


230.2 


236.3 


242.3 


279.8 


294-5 


356 


357 


317-1 


166.0 


170.9 


170.0 


163-7 


230.8 


236-9 


243-0 


280.6 


295-3 


357 


358 


318.0 


166.5 


171.4 


170.5 


164.3 


231-5 


237.6 


243-7 


281.4 


296 . 2 


358 


3S9 


318.9 


167.0 


171. 9 


171 .0 


164.8 


232.1 


238.3 


244-4 


282.2 


297-0 


359 


360 


319.8 


167-5 


172.5 


171. 5 


165-3 


232.8 


238.9 


245-1 


282.9 


297-8 


360 


36r 


320.7 


168.0 


173-0 


172. 1 


165.8 


233. 5 


239.6 


245.8 


283.7 


298-7 


361 


362 


321 .6 


! 168.5 


173-5 


172.6 


166.4 


234-1 


240.3 


246.4 


284.5 


299-5 


362 


363 


322.4 


j 169.0 


174-0 


173. 1 


166.9 


234.8 


241 .0 


247. I 


285.3 


300.3 


363 


364 


323-3 


169.6 


174.6 


173.7 


167.4 


235.4 


241 .6 


247.8 


286.1 


301 .2 


364 


36s 


324.2 


170. 1 


175-1 


174.2 


167.9 


236 . I 


242.3 


248.5 


286.9 


302.0 


36s 


366 


325. I 


170. 6 


175.6 


174-7 


168.5 


236.7 


243.0 


249.2 


287.7 


302.8 


366 


367 


326.0 


171 - I 


176 . I 


175-2 


169.0 


237-4 


243.6 


249.9 


288.5 


303-6 


367 


368 


326.9 


I 7 I . 6 


176. 7 


175-8 


169.5 


238.1 


244-3 


250.6 


289.3 


304-5 


368 


369 


327-8 


172 . I 


177-2 


176-3 


170.0 


238.7 


245-0 


251-3 


290.0 


305-3 


369 


370 


328.7 


172.7 


177-7 


176.8 


I 70. 6 


239-4 


245-7 


252-0 


290 . 8 


306. 1 


370 


371 


329- 5 


173-2 


178.3 


177-4 


171 . 1 


240.0 


246.3 


252-7 


291 . 6 


307.0 


371 


.372 


3.?o.4 


173-7 


178.8 


177.9 


171 . 6 


240.7 


247-0 


253-3 


292.4 


307-8 


372 


373 


ii^-^ 


174.2 


179-3 


178-4 


172.2 


241 -3 


247-7 


254.0 


293-2 


308.6 


373 


374 


332-2 


174-7 


179-8 


179.0 


172.7 


242 .0 


248.4 


254-7 


294-0 


309-5 


374 


375 


333-1 


175.3 


180.4 


179-5 


173-2 


242 .6 


2490 


255.4 


294-8 


310.3 


375 


376 


334-0 


175-8 


180. 9 


180.0 


173-7 


243.3 


249.7 


256 . I 


295.6 


311-1 


376 


377 


334-9 


176.3 


181. 4 


180.6 


174-3 


243-9 


250.4 


256.8 


296.4 


312.0 


377 


378 


335-8 


176.8 


182.0 


181. I 


174-8 


244.6 


251 .0 


257.5 


297-2 


312.8 


378 


379 


336-7 


177-3 


182.5 


181. 6 


I7S-3 


245-2 


251.7 


258.2 


297-9 


313-6 


379 


380 


337-5 


177-9 


183.0 


182. I 


175-9 


245-9 


252.4 


258.8 


298.7 


314-5 


380 


381 


338-4 


178.4 


183.6 


182.7 


176.4 


246. 6 


2S3-0 


259.5 


299-5 


315-3 


381 


382 


339-3 


178.9 


184. I 


183.2 


176.9 


247-2 


253-7 


260. 2 


300.3 


316. 1 


382 


383 


340-2 


179.4 


184.6 


183.8 


177-5 


247.9 


254-4 


260 . 9 


301. 1 


316.9 


383 


384 


341- I 


180 .0 


185.2 


184-3 


178.0 


248.5 


255-1 


261 .6 


301.9 


317-8 


384 


38s 


342.0 


180. 5 


185-7 


184.8 


178.5 


249-2 


255-7 


262 .3 


302.7 


318.6 


38s 


386 


342.9 


1 8 r . 


186.2 


185.4 


179-1 


249.8 


256.4 


263 .0 


303 - 5 


319.4 


386 


387 


343.8 


i8i .s 


186.8 


185-9 


179-6 


250.5 


257- I 


263.6 


304.2 


320.3 


387 


388 


344-6 


182.0 


187-3 


186.4 


180. 1 


251-1 


257-7 


264.3 


305-0 


321.1 


388 


389 


34S-5 


182.6 


187-8 


187.0 


180.6 


251-8 


258-4 


265.0 


305-8 


321.9 


389 


390 


346.4 


183. I 


188.4 


1875 


181. 2 


252.4 


259-1 


265.7 


306.6 


322.8 


390 


391 


347-3 


183.6 


188.9 


188.0 


181. 7 


253-1 


259-7 


266. 4 


307-4 


3236 


391 


392 


348-2 


184.1 


189.4 


188.6 


182.3 


2 53-7 


260. 4 


267 . I 


308.2 


324-4 


392 


393 


349-1 


184.7 


190.0 


189. I 


182.8 


254-4 


261 . I 


267.8 


309.0 


325-2 


393 


394 


3SO.O 


185.2 


190.5 


189-7 


183.3 


255-0 


261.8 


268. 5 


309.8 


326. 1 


394 



6o6 



FOOD INSPECTION /IND ANALYSIS. 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MALTOSE— (Cow<inMc<i). 

[Weights in milligrams.] 



o 


Copper (Cu). 


6 


1 
Q 


3 
u 

a 


Invert .Sugar 
and Sucrose. 


Lactose. 


Maltose. 





& 

o 
O 

1 

a 

3 
U 


"a 


d 


"(3 

H 

II 



6 


d 

DC 

+ 

6 
Si 

u 


d 

■f 

6 
%\ 

u 


d 

X 

c 


d 

X 

+ 
d 

X 

c 


3 



•c 
■3 


U) 

3 


3 
U 


395 


350-9 


185.7 


191 .0 


190 . 2 


183.9 


255-7 


262 . 4 


269. 1 


310.6 


326.9 


395 


396 


351.8 


:86.2 


191 .6 


190.7 


184.4 


256.3 


263. 1 


269.8 


311.4 


327.7 


396 


397 


352.6 


186.8 


192 . I 


191-3 


184.9 


257-0 


263.8 


270. 5 


312, 1 


328.6 


397 


398 


353. 5 


187.3 


192.7 


191-8 


185.5 


257.7 


264.4 


271.2 


312.9 


3294 


398 


399 


354.4 


187.8 


193.2 


192.3 


186.0 


258.3 


265 . 1 


271 .9 


313.7 


330.2 


399 


400 


335-3 


188.4 


193.7 


192.9 


186.5 


2S9-0 


265.8 


272 .6 


314.5 


331-1 


400 


401 


356.2 


188.9 


194.3 


193-4 


187. 1 


259-6 


266 . 4 


273.3 


315.3 


331-9 


401 


402 


357.1 


J 89. 4 


194.8 


194-0 


187.6 


260.3 


267 . 1 


274.0 


316. 1 


332.7 


402 


403 


358.0 


189.9 


195-4 


194-5 


188. 1 


260.9 


267.8 


274.6 


316.9 


333-6 


403 


404 


358.9 


190.5 


195-9 


195-0 


188.7 


261.6 


268. 5 


275. 3 


317.7 


334-4 


404 


40s 


359. 7 


191 . 


196.4 


195-6 


189.2 


262 .2 


269.1 


276.0 


318.5 


335-2 


40s 


406 


3 60 . 6 


191. 5 


197-0 


196. 1 


189.8 


262 .9 


269.8 


276.7 


319.2 


336-0 


406 


407 


361. 5 


192 . 1 


197-5 


196.7 


190.3 


263.5 


270. 5 


277.4 


320.0 


336-9 


407 


408 


362.4 


192 .6 


198. I 


197.2 


190.8 


264. 2 


271.1 


278.1 


320.8 


337-7 


408 


409 


363.3 


193. 1 


198.6 


197-7 


191. 4 


264 .8 


271.8 


278.8 


321.6 


338-s 


409 


410 


364.2 


193.7 


199.1 


198.3 


191.9 


265. 5 


272.5 


279.5 


322.4 


339-4 


410 


411 


365.1 


194.2 


199.7 


198.8 


192.5 


266. 1 


273-1 


280.1 


323-2 


340.2 


411 


412 


366.0 


19.1.7 


200. 2 


199.4 


193.0 


266.8 


273-8 


280.8 


324-0 


341 .0 


412 


413 


366.9 


195-2 


200 . 8 


1 99 . 9 


193.5 


267.4 


274-S 


281.5 


324-8 


341 .y 


413 


414 


367.7 


195-8 


201 . 3 


200. 5 


194.1 


268.1 


275-2 


282.2 


325.6 


342.7 


414 


41S 


368.6 


196.3 


201.8 


201 .0 


194.6 


268.7 


275-8 


282 .9 


326.3 


343.5 


41S 


416 


369.5 


196.8 


202 4 


201 .6 


195.2 


269.4 


276.5 


283.6 


327.1 


344-4 


416 


417 


370.4 


197.4 


202 .9 


202 . I 


195.7 


270. 1 


277-2 


284.3 


327.9 


345-2 


417 


418 


371 .3 


197.9 


203.5 


202 .0 


196. 2 


270.7 


277-8 


285.0 


328.7 


346.0 


418 


419 


372.2 


198.4 


204.0 


203.2 


196.8 


271.4 


278-5 


285.6 


329.5 


346.8 


419 


420 


373-1 


199.0 


204.6 


203.7 


197.3 


272 .0 


279-2 


286.3 


330.3 


347-7 


420 


421 


374-0 


199. 5 


205. 1 


204.3 


197.9 


272.7 


279-8 


287.0 


331 -1 


348.5 


42t 


422 


374-8 


200. I 


205.7 


204.8 


198.4 


273-3 


280. 5 


287.7 


331-9 


349.3 


422 


423 


375-7 


200.6 


206. 2 


205.4 


198.9 


274.0 


281 .2 


288.4 


332-7 


350-2 


423 


424 


376.6 


201 . I 


206. 7 


205.9 


1995 


274.6 


281.9 


289. 1 


333-4 


351-0 


424 


42s 


377-5 


201 . 7 


207.3 


206.5 


200.0 


275. 3 


282.5 


289.8 


334-2 


351-8 


42s 


426 


378.4 


202 . 2 


207.8 


207 .0 


200.6 


275-9 


283.2 


290.5 


33S-0 


352.7 


426 


427 


379-3 


202.8 


208. 4 


207 .6 


201 . I 


276 .0 


283.9 


291 . I 


335-8 


353.5 


427 


428 


380.2 


203.3 


208 . 9 


208. I 


201 . 7 


277-2 


284.5 


291 .8 


336-6 


354.3 


428 


429 


381 . T 


203.8 


209.5 


208.7 


202 . 2 


277-9 


285.2 


292.5 


337-4 


355-1 


429 


430 


382.0 


204.4 


210.0 


209 . 2 


202 . 7 


278.5 


285.9 


293.2 


338-2 


356.0 


430 


431 


382.8 


204.9 


210.6 


209.8 


203.3 


279.2 


286. 5 


293-9 


339-0 


356.8 


431 


432 


383.7 


205.5 


21 1 . 1 


210.3 


203.8 


279-8 


287.2 


294.6 


339-7 


357-6 


432 


433 


384.6 


206 .0 


211 .7 


210.9 


204.4 


280. s 


287.9 


295-3 


340.5 


358.5 


433 


434 


385.5 


206.5 


212.2 


21 1 .4 


204.9 


281.2 


288.6 


295.9 


341.3 


359-3 


434 


43 5 


386.4 


207 . 1 


212.8 


212.0 


205.5 


281.8 


289.2 


296.6 


342.1 


360. I 


435 


436 


387.3 


207 . 6 


213.3 


212.5 


206 . 


282. 5 


289.9 


297.3 


342.9 


361 .0 


436 


437 


388.2 


208.2 


213-9 


2 1 3 . 1 


206 . 6 


283.1 


290.6 


298.0 


343-7 


361.8 


'*H 


438 


389. I 


208.7 


214-4 


213.6 


207 . I 


283.8 


291.2 


298.7 


344.5 


362.6 


438 


439 


390.0 


209 . 2 


215.0 


214.2 


207.7 


284.4 


291 .9 


299.4 


345.3 


363-4 


439 


440 


390.8 


209.8 


2 1 5 - 5 


214.7 


208.2 


285.1 


292 .6 


300.1 


346.1 


364-3 


440 


441 


391.7 


210.3 


216. I 


215.3 


208.8 


285.7 


293.2 


300.8 


346.8 


365-1 


441 


442 


392.6 


210.9 


216.6 


215.8 


209.3 


286.4 


293 9 


301.4 


347.6 


365-9 


44a 


443 


393. s 


21 1 .4 


217.2 


216.4 


209. 9 


287.0 


294.6 


302. I 


348.4 


366.8 


443 


444 


394.4 


212.0 


217.8 


216.9 


210. 4 


287.7 


2J>5-3 


302.8 


349.2 


567.6 


444 


445 


395-3 


212.5 


218.3 


217-S 


2 1 1 . 


288.3 


295-9 


303 -5 


350.0 


368.4 


44S 


446 


396.2 


213.1 


218.9 


218.0 


211.5 


289.0 


296 . 6 


304-2 


350.8 


369-3 


446 


447 


397.1 


213.6 


219.4 


218.6 


2 12 . I 


289.6 


297-3 


304-9 


351.6 


370- I 


447 


448 


397.9 


214 I 


220.0 


219. 1 


212.6 


290.3 


297-9 


305-6 


352.4 


370-9 


448 


449 


398.8 


214.7 


220.5 


219.7 


213.2 


290.9 


298.6 


306.3 


353-2 


371-7 


449 



SUGAR AND SACCHARINE PRODUCTS. 



607 



ML'NSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, IN\-ERT 

SUGAR, LACTOSE, AND iLALTOSE— CCo«/J^««f^ 

[Weights in milligrams.] 



452 
453 
454 

455 
456 
457 
45* 
459 

460 
461 
462 
463 
464 

46s 
466 
467 
468 
469 

470 
471 
472 
473 
474 



476 
477 
478 
479 

480 
481 
482 
483 

484 

485 
486 
487 
488 
489 

490 



6 








Invert Sugar 
1 and Sucrose. 


Lactose. 


Maltose. 





3 












S 











1 




^- 











c 








= 


— 


» 







c 


1* 


■— 






^ 


- 


^ 


— 






r^ 


- 


X 


■^ 




::: 


' . 


c 


.<» 






•— 














"_ 


r- 


— 




— 




cc 

1 


p 




■f. 


-- ? 


5 5 


^ i 


3 


g 


c 


C 



'Z'-i'' 



399 7 
400.6 
401.5 
402.4 
403-3 

404.2 
405. I 
405-9 
406.8 
407 -7 

408.6 
409.5 
410.4 
411 -3 
412.2 

413-0 
413-9 
414.8 
415-7 
416.6 

417-S 
418.4 
419-3 
420.2 
421.0 

421.9 
422.8 
423 7 
424.6 
425-5 

426.4 
427 3 
428.1 
429-0 
429.9 

430.8 
431-7 
432-6 
433 S 
434.4 

435-3 



215.2 221. I 

215.8 221.6 

216.3 I 222.2 

216.9 222.8 

217.4 223.3 



218.0 
218.5 
219. I 
219.6 
220.2 

220.7 
221.3 
221.8 
222.4 
222 .9 



223.9 
224.4 



226.1 

226. 7 
227.2 
227.8 
228.3 
228.9 



220.2 
220.8 
221.4 
221.9 
222. S 

223.0 
223.6 
224.1 
224.7 
225.3 

225.8 
226.4 
226.9 
227.5 
228.1 



213.7 291.6 
214.3 292.3 

214.8 I 292.9 
2IS-4 293.6 
2x5.9 294-2 



216.5 
217.0 
217.6 
218. 1 
218.7 

219.2 
219.8 
'!20.3 
220 9 
221.4 



223.5 229.5 

224.0 i 230.0 

224.6 I 230.6 

225.1 I 231.2 

225.7 231.7 



228.6 222.0 
229.2 222.5 

229.7 223.1 



226.2 
226.8 



228. 



232.3 
232-8 
233 4 
234-0 
234-5 



230-3 
230.9 

i 

: 231.4 
232.0 

4-232-S 
233.1 
233.7 



229.0 235-1 

229.6 235.7 

230.1 236.2 

230.7 I 236.8 
231-3 I 237.4 



234-2 
234-8 
235-4 
235-9 
236.5 



223.7 
224.2 

224.8 
225.3 
225.9 
226.4 
227.0 

227.6 
228.1 
228.7 
229.2 
229.8 



231.8 
232.4 
232.9 
233 -5 
234-1 

234.6 
235.2 
235-7 
266.3 
236.9 



237-9 
238 S 
239-1 
239.6 
240.2 

240.8 
241.4 
241.9 

242-5 
243 -» 



237-1 230.3 

237-6 230.9 

238.2 231.5 

238.8 I 232.0 

239-3 232.6 



239.9 
240.5 
241 .0 
24t.6 

242.2 



233-2 
233-7 
234-3 
234-8 

235-4 



299-3 306.9 

299.9 307-6 

300.6 308.3 

301.3 I 309-0 

302.0 309-7 



294-9 
295-5 
296.2 
296.8 
297-5 



302.6 
303-3 
304.0 
304.6 
305-3 



310.4 
311-r 
3x1.8 
312.4 
3*3-» 



298.1 306.0 3*3-8 

298.8 306.6 314-5 

299-4 307-3 315-2 

300 I 308.0 3x5.9 

300.7 308.7 3»6.6 



237-4 243-6 242.7 ' 236.0 

I I I 



301.4 
302.0 
302.7 
303-3 
304.0 

304-7 
30S-3 
306.0 
306.6 
307-3 

307-9 
308.6 
309.2 
309-9 
310.5 

3x1.2 
311. 8 
3»2.5 
3i3-t 
313-8 

3*4-4 
3»S-* 
3*5-8 
3*6.4 
3*7-1 



309-3 
3*0.0 
310.7 
3**. 3 

3x2.7 
3*3-3 
3x4.0 
3*4-7 
3*5-4 

3x6.0 
3*6.7 
3*7-4 
3*8.0 
3*8.7 

3*9.4 
320.0 
320.7 
32*. 4 
322.1 

322.7 
323-4 
324-* 
324-7 
325-4 



3*7-3 

3*7-9 

, 3*8.6 

I 3*9.3 

320.0 

320.7 
321.4 
322.1 
322.8 
I 323-4 

324-x 
324-8 
325-S 
326.2 
326.9 

327-6 
328.2 
328.9 
329.6 
330.3 

33* -0 
33*-7 
332.4 
333-* 
333-7 



317-7 326.1 I 334-4 



353-9 
354-7 
355-5 
356-3 
357* 

357-9 
358-7 
359-5 
360.3 
361 .0 

361.8 
362.6 
363-4 
364-2 
365-0 

365-8 
366.6 
367-3 
368.1 
368.9 

369-7 
370.5 
37*-3 
372-1 
372.9 

373-7 
374-4 
375-2 
376.0 
376.8 

377-6 
378.4 
379-2 
380.0 
380.7 

381-5 
382.3 
383* 
383-9 
384-7 

38s -S 



372.6 
373-4 
374-2 
375* 
375-9 

376-7 
377-6 
378.4 
379-2 
380.0 

380.9 
381.7 
382. S 
383 -4 
384-2 

385.0 
385-9 
386.7 

387. 5 
388.3 

389 2 
390-0 
390-8 
391-7 
392.5 

393 3 
394-2 
395 o 
395-8 
396.6 

397-5 
398.3 
399* 
400.0 
400. 8 

401 .6 
402.4 
403-3 
404 -* 
404.9 



y 



450 
45* 
452 

453 
454 

455 
456 
457 
45* 
459 

460 
461 
462 
463 
464 

465 
466 
467 
468 
469 

470 
47* 
472 
473 
474 

475 
476 
477 
478 
479 

480 
481 
482 
483 
484 

485 
486 
487 
488 
489 



405.8 490 



6o8 FOOD INSPECTION AND ANALYSIS. 

AUihn's Method for the Determination of Dextrose.* — The solutions 
used arc those described on \y<^g^ ^gi, except that 125 grams of potassium 
hydroxide are used in place of 50 grams of sodium hydroxide in preparing 
the alkaline tartrate solution. Place 30 cc. of Fehling's copper solution, 
30 cc. of the alkaline tartrate solution, and 60 cc. of water in a beaker 
and heat to boiling. Add 25 cc. of the sugar solution, which must be 
so pre])ared as not to contain more than 1% dextrose, and boil over the 
llame for two minutes. Filter immediately without diluting through a 
Gooch crucible containing a layer of asbestos fiber, prepared as described 
on page 594, and wash thoroughly with hot water, using reduced pressure. 
Transfer the asbestos fiber and the adhering cuprous oxide by means of 
a glass rod to a beaker and rinse the crucible with about 30 cc. of a boiling 
mixture of dilute sulphuric and nitric acids containing 65 cc. of sulphuric 
acid (s{)ecific gravity 1.84) and 50 cc. of nitric acid (specific gravity 
1.42) per liter. Heat and agitate till the solution is complete, then fiher 
into a scrupulously clean, tared platinum dish of loo-cc. capacity, taking 
care to wash out all the copper solution from the filter into the dish. 
Deposit the copper electrolytically in the platinum dish and weigh. Deter- 
mine the dextrose from Allihn's table, p. 609. 

Or, the metallic copper may be calculated by means of the factor 
0.7989 from the cupric oxide obtained as in Defren's methorl (p. 594) 
and Allihn's table used. 

Or, the cuprous oxide as directly obtained by either Allihn's or Defren's 
method may be washed with alcohol and ether, dried for twenty minutes 
at 100° C, and weighed, its equivalent in dextrose being ascertained from 
Allihn's table. 

Electrolytic Apparatus.^The author has devised the apparatus shown 
in Fig. I ID for the electrolytic deposition of copper in sugar analysis and for 
other work of like nature. A, Fig. no, is a hard-rubber plate 50 cm. 
long and 25 cm. wide provided with four insulated metal binding posts, J5, 
each carrying at the top a thumb screw by which a coiled platinum wire 
electrode, C, may be attached. In front of each post is a copper plate 
about 4 cm. square covered with thin platinum foil, P, which is bent 
around the edges of the copper plate and so held in place, the copper plate 
being screwed to the rubber from beneath. On the square platinum- 
covered plate is set the platinum evaporating-dish which holds the solu- 
tion from which the copper is to be deposited, the inside of the dish form- 
ing the cathode, while the electrode C, dipping below the surface of the 
solution, forms the anode. In front of each platinum-covered plate 

* Tour, ftir praktische Chemie, 22 (1880), p. 46. 



SUGAR AND SACCHARINE PRODUCTS. 



609 





ALLIHN'S TABLE FOR THE DETERMINATION OF DEXTROSE 


* 


Milli- 


MilU- 


Milli- 


MilU- 


MilU- 


MilU- 


MilU- 


Milli- 


MilH- 


Milli- 


Milli- 


Milli- 


grams 


grams 


grams 


grams 


gram.s 


gram.s 


grams 


grams 


grams 


grams 


grams 


grams 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


Cop- 


prous 


Dex- 


Cop- 


prous 
Oxide. 


Dex- 


Cop- 


prous 
Oxide. 


Dex- 


Cop- 


prous 


Dex- 


per. 


Oxide. 


trose. 


per. 


trose. 


per. 


trose. 


per. 


Oxide. 


trose. 


II 


12.4 


6.6 


76 


85.6 


38.8 


141 


158.7 


71.8 


206 


231-9 


105.8 


12 


I3S 


7.1 


77 


86.7 


39.3 


142 


159.9 


72.3 


207 


233-0 


106.3 


13 


14. 6 


7.6 


78 


87.8 


39.8 


143 


161 .0 


72.9 


208 


234-2 


106.8 


14 


15-8 


8.1 


79 


88.9 


40.3 


144 


162. 1 


73.4 


209 


235.3 


107.4 


IS 


16.9 


8.6 


80 


90. 1 


40.8 


145 


163.2 


73.9 


210 


236-4 


107-9 


16 


18.0 


9.0 


81 


91 . 2 


41.3 


146 


164.4 


74.4 


211 


237.6 


108.4 


17 


19.1 


95 


82 


92.3 


41.8 


147 


165 -S 


74-9 


212 


238.7 


109.0 


18 


20.3 


10. 


83 


93-4 


42.3 


148 


166.6 


75.5 


213 


239-8 


109 5 


19 


21.4 


10. s 


84 


94-6 


42.8 


149 


167.7 


76.0 


214 


240.9 


IIO.O 


ao 


22.5 


II .0 


85 


95-7 


43-4 


ISO 


168.9 


76. 5 


215 


242.1 


110.6 


31 


23.6 


II. s 


86 


96.8 


43-9 


iSi 


170.0 


77.0 


316 


243.2 


III. I 


33 


24-8 


12.0 


87 


97.9 


44.4 


152 


171.1 


77-5 


217 


244-3 


III .6 


a3 


25-9 


12.5 


88 


99-1 


44.9 


IS3 


172.3 


78.1 


218 


245-4 


1 12. 1 


24 


27 .0 


130 


89 


100. 2 


45. 4 


154 


173.4 


78.6 


319 


246.6 


112.7 


as 


28.1 


13. S 


90 


101.3 


45.9 


155 


174. s 


79-1 


220 


247.7 


113.3 


36 


39-3 


14.0 


91 


102.4 


46.4 


156 


175. 6 


79-6 


221 


248.7 


113-7 


37 


30-4 


14. S 


92 


103.6 


46.9 


157 


176.8 


80.1 


222 


249.9 


114.3 


38 


31S 


iS.o 


93 


104.7 


47.4 


158 


177.9 


80.7 


223 


251 .0 


114-8 


39 


32.7 


15-5 


94 


105.8 


47.9 


1 59 


179-0 


81.2 


224 


252.4 


iiS-3 


30 


33.8 


16.0 


9S 


107.0 


48.4 


160 


180. 1 


81.7 


225 


253-3 


115-9 


31 


34-9 


16. 5 


96 


108. 1 


48.9 


161 


181. 3 


82.2 


226 


254-4 


116. 4 


33 


36.0 


17.0 


97 


109.2 


49-4 


162 


182.4 


82.7 


227 


255-6 


1 16.9 


33 


37-2 


17.5 


98 


110.3 


49-9 


163 


183.5 


83-3 


228 


256.7 


117. 4 


34 


38.3 


18.0 


99 


111.5 


50-4 


164 


184.6 


83-8 


229 


257-8 


118.0 


35 


39-4 


18. s 


100 


112.6 


SO. 9 


i6s 


185.8 


84.3 


230 


258.9 


118. S 


36 


40. s 


18.9 


lOI 


113. 7 


Si-4 


166 


186.9 


84-8 


231 


260. 1 


119. 


37 


41-7 


19.4 


102 


114.8 


51-9 


167 


188.0 


85.3 


232 


261.2 


119. 6 


38 


42.8 


19.9 


103 


116.0 


52.4 


168 


189. 1 


85.9 


233 


262.3 


120. 1 


39 


43-9 


20.4 


104 


117. 1 


52.9 


169 


190-3 


86.4 


234 


263.4 


120.7 


40 


4S-0 


30.9 


los 


118.2 


SiS 


170 


191-4 


86.9 


235 


264.6 


121.2 


41 


46.2 


21.4 


106 


119. 3 


S4-0 


171 


192.5 


87-4 


236 


265.7 


121.7 


42 


47-3 


21.9 


107 


120. 5 


54.5 


172 


193.6 


87.9 


237 


266.8 


122.3 


43 


48.4 


22.4 


108 


121 .6 


S5-0 


173 


194.8 


88.5 


238 


268.0 


122.8 


44 


49- 5 


22.9 


109 


122.7 


55-5 


174 


195-9 


89.0 


239 


269. 1 


123.4 


45 


50-7 


23.4 


no 


123.8 


56.0 


I7S 


197.0 


89. S 


240 


270. 2 


123.9 


46 


SI. 8 


23.9 


in 


125.0 


S6.5 


176 


198.1 


90.0 


241 


271.3 


124.4 


47 


52-9 


24.4 


112 


126. 1 


57. 


177 


199-3 


90.5 


242 


272. 5 


125.0 


48 


540 


24.9 


113 


127.2 


57. S 


178 


200.4 


91.1 


243 


273-6 


I2S-5 


49 


SS-2 


25-4 


114 


128.3 


58.0 


179 


201. 5 


91 .6 


244 


274-7 


126.0 


SO 


S6.3 


25.9 


IIS 


129.6 


S8.6 


180 


202.6 


92.1 


24s 


275-8 


126.6 


51 


57.4 


26.4 


116 


130.6 


SO.i 


181 


203.8 


92.6 


246 


277.0 


127.1 


S3 


S8.5 


26.9 


H7 


131.7 


59-6 


182 


204.9 


93-1 


247 


278.1 


127.6 


S3 


S9-7 


274 


118 


132.8 


60. 1 


183 


206.0 


93-7 


248 


279-2 


128. 1 


54 


60.8 


27.9 


119 


134.0 


60.6 


184 


207. 1 


94-2 


249 


280.3 


128.7 


55 


61 .9 


28.4 


120 


135-1 


61.1 


185 


208.3 


94-7 


250 


281. S 


129.3 


56 


63.0 


28.8 


121 


136-2 


61.6 


186 


209.4 


95.2 


251 


282.6 


129-7 


57 


64.2 


29-3 


122 


137-4 


62.1 


187 


210. 5 


95-7 


252 


283.7 


130.3 


58 


65-3 


29.8 


123 


138-5 


62.6 


188 


211. 7 


96.3 


253 


284-8 


130.8 


59 


66.4 


30.3 


124 


139.6 


63.1 


189 


212.8 


96.8 


254 


286.0 


131. 4 


60 


67.6 


30.8 


125 


140.7 


63-7 


190 


213.9 


97.3 


2SS 


287.1 


131. 9 


61 


68.7 


31-3 


126 


141. 9 


64-2 


191 


215.0 


97.8 


256 


288.2 


132.4 


62 


69.8 


31.8 


127 


1430 


64-7 


192 


216. 2 


98.4 


257 


289.3 


133-0 


63 


70.9 


32.3 


128 


144.1 


6s-2 


193 


217-3 


98.9 


258 


290.5 


133-S 


64 


72.1 


32.8 


129 


145-2 


65.7 


194 


218.4 


99-4 


259 


291 .6 


134. 1 


6S 


73-2 


33.3 


130 


146-4 


66.2 


195 


219. 5 


1 00.0 


260 


292.7 


134-6 


66 


74-3 


33.8 


131 


147-5 


66.7 


196 


220. 7 


100.5 


261 


293-8 


135-1 


67 


75-4 


34-3 


132 


148.6 


67. 2 


197 


221.8 


lOI .0 


262 


29S-0 


135-7 


68 


76.6 


34-8 


133 


149-7 


67.7 


198 


222.9 


101 . 5 


263 


296. 1 


136. 2 


69 


77-7 


35-3 


134 


ISO. 9 


68.2 


199 


224.0 


102.0 


264 


297-2 


136.8 


70 


78.8 


35-8 


I3S 


152.0 


68.8 


200 


225.2 


102.6 


265 


298-3 


137.3 


71 


79-9 


36.3 


i 136 


153-1 


69.3 


201 


226.3 


103. 1 


266 


299-5 


137.8 


73 


81. 1 


36.8 


137 


154.2 


69.8 


202 


227.4 


I03-7 


267 


300.6 


138.4 


73 


82.2 


37-3 


138 


lSS-4 


70.3 


203 


228.5 


104. 2 


268 


301.7 


I3«.9 


74 


83.3 


37.8 


139 


156.5 


70.8 


204 


229.7 


104.7 


269 


302.8 


139.5 


75 


84.4 


38.3 


140 


157.6 


71.3 


205 


230.8 


105.3 


270 


304-0 


140.0 



* U. S. Dept. of Agric. Bur. of Chem.. Bui. 65. p i43 



6io 



FOOD INSPECTION yIND ANALYSIS. 



ALLIHN'S TABLE FOR THE DETERMINATION OF DEXTROSE— (Con/iwMcd). 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


MilU- 


MilU- 


Milli- 


Milli- 


Milli- 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


Cop- 


prous 
Oxide. 


Dex- 


Cop- 


prous 
Oxide. 


Dex- 


Cop- 


prous 
Oxide. 


Dex- 


Cop- 


prous 
Oxide. 


Dex- 


per. 


trose. 


per. 


trose. 


per. 


trose. 


per. 


trose. 


271 


305-1 


140.6 


321 


361.4 


168. 1 


371 


417.7 


196.3 


421 


474.0 


225.1 


272 


306.2 


J41 . 1 


322 


362. 5 


168.6 


372 


418.8 


196.8 


422 


475-6 


225-7 


273 


307.3 


141. 7 


323 


363-7 


169. 2 


373 


420. 


197-4 


423 


476-2 


226. 3 


274 


308.5 


142. 2 


324 


364-8 


169.7 


374 


421 . 1 


198.0 


424 


477.4 


226.9 


27s 


309.6 


142.8 


325 


365-9 


170.3 


375 


422. 2 


198.6 


425 


478.5 


227-5 


276 


310.7 


143.3 


326 


367.0 


170.9 


376 


423.3 


199.1 


426 


479.6 


228.0 


277 


311.9 


143.9 


327 


368.2 


171. 4 


377 


424. 5 


199.7 


427 


480.7 


228.6 


278 


313.0 


144.4 


328 


369-3 


172.0 


378 


425.6 


200.3 


428 


481 .9 


229. 2 


279 


314. 1 


145.0 


329 


370.4 


172.5 


379 


426.7 


200. 8 


429 


483.0 


229.8 


280 


315.2 


145. 5 


no 


371.5 


173. 1 


380 


427.8 


201 .4 


430 


484.1 


230.4 


281 


316.4 


146- I 


331 


372.7 


173.7 


381 


429.0 


202.0 


431 


485.3 


231.0 


282 


317.5 


146. 6 


332 


373.8 


174.2 


382 


430.1 


202. 5 


432 


486.4 


231 .6 


283 


318.6 


147.2 


333 


374-9 


174.8 


383 


431.2 


203. 1 


433 


487.5 


232.2 


284 


319.7 


147.7 


334 


376.0 


175.3 


384 


432.3 


203.7 


434 


488.6 


232.8 


28s 


320.9 


148.3 


335 


377.2 


17s. 9 


38s 


433. 5 


204.3 


435 


489.7 


233-4 


286 


3220 


148.8 


336 


378-3 


176.5 


386 


434.6 


204.8 


436 


• 
490.9 


233-9 


287 


323.1 


149.4 


337 


379-4 


177.0 


387 


435.7 


205.4 


437 


492.0 


234-S 


288 


324.2 


149.9 


338 


380.5 


177-6 


388 


436.8 


206. 


438 


493 - I 


235-1 


289 


325.4 


150.5 


339 


381-7 


178. I 


389 


438.0 


206.5 


439 


494-3 


235-7 


290 


326.5 


151 -0 


340 


382.8 


178.7 


390 


439.1 


207 . 1 


440 


495-4 


236-3 


291 


327.4 


151. 6 


341 


383-9 


179-3 


391 


440.2 


207.7 


441 


496.5 


236.9 


292 


328.7 


152. 1 


342 


385-0 


179-8 


392 


441 . 3 


208.3 


442 


497-6 


237-5 


293 


329.9 


152.7 


343 


386.2 


180.4 


393 


442-4 


208.8 


443 


498.8 


238.1 


294 


331 .0 


153-2 


344 


387.3 


180.9 


394 


443 - 6 


209.4 


444 


499-9 


238.7 


29s 


332.1 


153-8 


345 


388.4 


181. 5 


395 


444.7 


210.0 


445 


501 .0 


239-3 


296 


333-3 


154-3 


346 


389.6 


182. 1 


396 


445. 9 


210.6 


446 


502. I 


239.8 


297 


334.4 


154-9 


347 


390.7 


182.6 


397 


447.0 


21 1 . 2 


447 


S03-2 


240.4 


298 


335.5 


155-4 


348 


391.8 


183.2 


398 


448. I 


211.7 


448 


S04-4 


241 .0 


299 


336.6 


156-0 


349 


392.9 


183-7 


399 


449.2 


212.3 


449 


505-5 


241 . 6 


300 


337.8 


156.3 


350 


394.0 


184-3 


400 


450.3 


212.9 


450 


506.6 


242. 2 


301 


338.9 


157-1 


351 


395.2 


184.9 


401 


451.5 


213. 5 


451 


507-8 


242.8 


302 


340.0 


157-6 


352 


396.3 


185.4 


402 


452.6 


214. 1 


452 


508.9 


243.4 


303 


341. 1 


158.2 


353 


397-4 


186.0 


403 


453.7 


214. 6 


453 


510.0 


244.0 


304 


342.3 


158.7 


354 


398-6 


186.6 


404 


454.8 


215. 2 


454 


511.1 


244.6 


305 


343.4 


159-3 


355 


399 - 7 


187.2 


40s 


456.0 


215.8 


455 


512.3 


245.2 


306 


344. S 


IS9-8 


356 


400.8 


187-7 


406 


457.1 


216.4 


456 


513-4 


"245.7 


307 


345-6 


160.4 


357 


401 -9 


188.3 


407 


458.2 


217.0 


45 7 


514-5 


246.3 


308 


346.8 


160. 9 


358 


403 - I 


188.9 


408 


459.4 


217.5 


458 


S15.6 


246.9 


309 


347-9 


161 .5 


359 


404.2 


189.4 


409 


460.5 


218. I 


459 


S16.8 


247 -5 


310 


349.0 


162.0 


360 


405-3 


190.0 


410 


461.6 


218.7 


460 


517.9 


248.1 


311 


350.1 


162.6 


361 


406 . 4 


190.6 


411 


462.7 


219.3 


461 


519-0 


248.7 


312 


351.3 


163 . 1 


362 


407.6 


191 . I 


412 


463.8 


219.9 


462 


520. 1 


249-3 


313 


352.4 


163-7 


363 


408.7 


191 .7 


413 


465-0 


220.4 


463 


521.3 


249.9 


314 


353.5 


164. 2 


364 


409 . 8 


192.3 


414 


466 . I 


221.0 








31S 


354.6 


164.8 


36s 


410.9 


192.9 


415 


467.2 


221.6 








316 


355. 8 


165-3 


366 


41 2 . 1 


193-4 


416 


468.4 


222. 2 








317 


356.9 


165-9 


367 


413.2 


194.0 


417 


469. 5 


222.8 








318 


358.0 


166.4 


368 


414.3 


194.6 


418 


470.6 


223.3 








319 


359-1 


167 .0 


369 


415.4 


195- I 


419 


471.8 


223.9 








320 


360.3 


167-5 


370 


416.6 


195-7 


420 


472.9 


224. 5 









is a switch, S, and at either end of the hard-rubber plate is a binding 
post, R, for connection with the electric current. The wiring, which 
is on the under side of the rubber plate, is best illustrated by the diagram 
in Fig. no. 

Four determinations may be carried on simultaneously in four plat- 
inum dishes, if desired, the wiring and the switches being so arranged 
that beginning at one end of the plate cither the first dish or the first 



SUGAR AND SACCHARINE PRODUCTS. 



6ll 




Fig. iio. — Four Pan Electrolytic Apparatus, shown ("above) with Glass-ccvered Top 
Partially Removed, and Cbelow) in Diagram. 



6i2 FOOD INSPECTION AND ANALYSIS. 

two or the first three may be thrown in or out of circuit at will without 
interrupting the current through the remaining dishes. A cover with 
wooden sides and glass top fits closely over the whole apparatus as a 
protection from dust, but may be easily lifted off to manipulate the 
dishes when desired. The sides of the cover are perforated to permit 
the escape of the gas formed during the electrolysis. 

The ordinary street current is used when available, and the strength 
of the current may be varied within wide limits by means of a number 
of i6 or 32 candle-power lamps, K, coupled in multiple, and a rheostat, 
L, consisting of a vertical glass tube sealed at the bottom, containing a 
column of dilute acid, the resistance being changed by varying the length 
of the acid column contained between the two platinum terminals immersed 
therein, one of which is movable, A gravity battery of four cells may 
be employed if the laboratory is not equipped with electric lights. 

In using this apparatus for determining copper, as in sugar work, 
the plating process should go on till all the copper is deposited, requiring 
several hours or over night with a current strength of about 0.25 ampere. 
Before stopping the process, the absence of copper in the solution should 
be proved by removing a few drops with a pipette, adding first ammonia, 
then acetic acid, and testing vdth ferrocyanide of potassium. If no 
brown coloration is produced, all the copper has been plated out. Throw 
the dish out of circuit by means of the switch, pour out the acid solution 
quickly before it has a chance to dissolve any of the copper, wash the 
dish first with water and then with alcohol, dry, and weigh. 

The copper may be removed from the platinum dish by strong nitric 
acid. 

Determination of Sucrose by Fehling's Solution.* — If a polariscope is 
not available, cane sugar can be determined as follows : First determine the 
percentage of invert sugar present in the sample by one of the Fehling 
methods already described. Then dissolve i gram of the sugar in about 
100 cc. of water in a 500-cc. graduated flask, add 3 cc. of concentrated 
hydrochloric acid and invert by heating in water to 68° and cooling in the 
regular manner. Neutralize with sodium hydroxide or sodium carbonate, 
and make up to the mark with water. Determine the per cent of total 
reducing sugar as invert sugar either by the volumetric or gravimetric 
Fehling process. Subtract the invert sugar found present in the sugar by 
direct determination from the total found present after inversion, and 

* Tucker, Manual of Sugar Analysis, p. 182. 



SUGAR AND SACCHARINE PRODUCTS. 6I3 

the remainder is the invert sugar due to cane sugar. This figure multi- 
plied by 0,95 gives the percentage of cane sugar. 

For the determination of sucrose by the gravimetric Fehling process on 
the inverted sample, multiply the cupric oxide (CuO) by the factor 0.4307, 
or the copper (Cu) by the factor 0.5394. 



ANALYSIS OF MOLASSES AND SYRUPS, 

First insure a perfectly homogeneous sample by stirring with a rod 
to evenly distribute any separated sugar. 

Determination of Total Solids. — (i) Asbestos Method. — Weigh 20 
grams into a loo-cc. graduated flask, dissolve in water, and make up to 
the mark. Insure a uniform solution by shaking. Measure 10 cc. of 
this solution into a tared platinum dish containing about 5 grams of 
freshly ignited, finely divided asbestos fiber, and dry to constant weight 
at 70° in vacuo, or in a McGill oven (see p. 586). 

(2) Sand Method.^ — Place about 15 grams of ignited quartz sand and 
a stirring rod in a flat-bottom metal dish and wxigh. Add 2 to 4 grams 
of the material and sufficient moisture to permit thorough mixing. Dry 
on a water bath with stirring and finally in a water oven until the loss in 
weight in one hour is not more than 3 mg. At least 8 hours' heating is 
usually required. 

(3) By Calculation from Refractive Index. — Determine the refractive 
index by means of the Abbe refractometer (p. 108), and calculate the 
total solids, using GeerHgs's tables (p. 615). 

This method is more accurate and convenient than the specific gravity 
method and employs a smaller quantity of material. The investigations 
of Stollef and of Tolman and SmithJ have shown that sucrose, maltose, 
dextrose, levulose and lactose all have practically the same refractive index. 
Dextrin has a somewhat higher refractive index, nevertheless the solids 
of commercial glucose do not give a reading appreciably higher than 
the sugars named. 

A. H. Bryan, § has compared this method with the method of drying 
at 70° in vacuo, with the following results: 

* U. S. Dept. Agric, Bur. of Chem., Bui. 107 (rev.), p. 65. 
t Zeits. deutsch. Zucker-Ind., 1901, pp. 335, 469. 
X Jour. Am. Chem. Soc, 28, 1906, p. 1476. 
§ Ibid., 30, 1908, p. 1443. 



6 14 FOOD INSPECTION AND ANALYSIS. 

Material. Number of Difference compared 

Samples. with the Gravimetric Method. 

Maple syrup 13 -1.3410+0.72 

Cane table syrup 10 —0.79" +0.62 

Cane molasses 17 — 1.53 " +0.59 

Beet molasses 15 — 1-83 " —0.07 

Honey 24 -2.52" +0.91 

Glucose 2 -0.27 " +0.27 

(4) By Calculation from Specific Gravity. — Weigh 25 grams of the 
sample into a loo-cc. graduated flask, dissolve in water, and make up 
to the mark. Determine the specific gravity of the diluted solution by 
means of a pycno meter or Westphal balance. Ascertain from the table 
on pp. 617-620 the percentage by weight of solids (sugar) corresponding 
to the specific gravity of the diluted solution, and calculate the total solids 
in the original sample by the formula 

Solids in original sample = 42)5', 
D being the specific gravity of the diluted solution and S the per cent 
of solids in the diluted solution. 

Determination of Ash. — ^Weigh from 5 to 10 grams of the sample 
into a tared platinum dish, evaporate to dryness on the water-bath, and 
proceed as directed for ash of sugar (p. 586). 

Polarization and Determination of Sucrose. — Molasses and golden 
syrup require the apphcation of clarifying reagents before a sufficiently 
clear solution can be obtained for reading on the polariscope. Even 
then it is not possible nor is it necessary to get a water-white solution, so 
that in this class of products greater accuracy can usually be attained by 
polarizing in a 100- mm. tube (half the standard length) and multiplying 
the reading by 2. The clarifier best adapted as a rule for molasses and 
golden syrup is subacetate of lead.* 

The Process. — The normal weight, 26.048 grams, of the molasses or 
syrup is dissolved in water in a loo-cc. flask, and in the case of molasses and 
"golden," or "drip" syrup, sufficient subacetate of lead solution is added 
to precipitate the coloring matter. From 5 to 10 cc. of the clarifier 
usually suffice. The flask is then filled to the mark with water and the 
contents shaken thoroughly and filtered. If on account of air bubbles 
It is difficult to make up to the mark, the bubbles may usually be dis- 
pelled by a drop of ether. With maple syrup no clarifier is, as a rule, 
necessary, though sometimes alumina cream is helpful. With a very 

* Alumina cream, p. 587, and bone black, or animal char, are also useful. 



SUGAR AfW SACCHARINE PRODUCTS. 



6iS 



GEERLIGS'S TABLE FOR DRY SUBSTANCE IX SUGAR-HOUSE PRODUCTS 
BY THE ABBE REFRACTOMETER, AT 28° C* 





Per 








Per 




Refrac- 


Cent 


Decimals to be Added for I 


Refrac- 


Cent 


Decimals to be Added for 


tive 
Index. 


Dry 
Sub- 


Fractional Readings, f j 


tive 
Index. 


Dry 
Sub- 


Fractional Readings, t 




stance. 




1 




stance. 




1-3335 


I 


0.0001 = 0.05 


0.0010 = 0.75 


1.4083 


45 


0.0004 = 0.2 


0.0015 = 0.75 


1-3349 


2 


0.0002 = 0.1 


0.0011=0.8 


1.4104 


46 


0.0005 = 0.25 


0.0016 = 0.8 


1-3364 


3 


0.0003 = 0.2 


0.0012 = 0.8 


I. 4124 


47 


0.0006 = 0.3 


0.0017 = 0.85 


1-3379 


4 


0.0004 = 0.25 


0.0013 = 0.85 


I. 4145 


48 


0.0007 = 0.35 


0.0018 = 0.9 


1-3394 


5 


0.0005 = 0.3 


0.0014 = 0.9 


I. 4166 


49 


. 0008 = 0.4 


0.0019 = 0.95 


1-3409 


6 


. 0006 = 0.4 


0.0015=1.0 


I. 4186 


50 


0.0009 = 0.45 


0.0020= I.O 


1-3424 


7 


0.0007 = 0.5 




1.4207 


51 


0.0010 = 0.5 


0.0021 = 1.0 


T-3439 


8 


. 0008 = 0.6 




1.4228 


52 


0.0011 = 0.55 




1-3454 


9 


0.0009=0.7 




I. 4219 


53 






1.3469 


10 






1.4270 


54 






1.3484 


II 


0.0001 = 0.05 




1.4292 


55 


0.0001 = 0.05 


0.0013 = 0.55 


1-3500 


12 


0.0002 = 0.1 




I-4314 


56 


0.0002 = 0.1 


0.0014=0.6 


I-3516 


13 


. 0003 = 0.2 




1-4337 


57 


. 0003 = 0.1 


0.0015 = 0.65 


1-3530 


14 


0.0004 = 0.25 




1-4359 


58 


0.0004 = 0.15 


0.0016 = 0.7 


1-3546 


15 


0.0005 = 0.3 




1.4382 


59 


0.0005 = 0.2 


0.0017 = 0.75 


1-3562 


16 


0.0006 = 0.4 




1-4405 


60 


0.0006 = 0.25 0.0018=0.8 


1.3578 


17 


0.0007 = 0.45 




1.4428 


61 


0.0007 = 0.3 


0.0019=0.85 


1-3594 


18 


0.0008 = 0.5 




I -4451 


62 


0.0008 = 0.35 


0.0020=0.9 


1.3611 


19 


0.0009 = 0.6 




1-4474 


63 


0.0009=0.4 


0.0021=0.9 


1.3627 


20 


0.0010 = 0.65 




1.4497 


64 


0.0010 = 0.45 


0.0022 = 0.95 


1-3644 


21 


0.0011 = 0.7 




1.4520 


65 


0.0011 = 0.5 


0.0023 = 1.0 


1. 3661 


22 


0.0012 = 0.75 




1-4543 


66 


0.0012 = 0.5 


0.0024=1.0 


1.3678 


23 


0.0013 = 0.8 




1.4567 


67 






1-3695 


24 


0014 = 0.85 




I -4591 


68 






1. 3712 


25 


0.0015 = 0^9 




I. 4615 


69 






1-3729 


26 


0.0016 = 0.95 




1.4639 
1.4663 
1.4687 


70 
71 
72 
















1-3746 
1-3764 
1.3782 


27 
28 
29 


0.0001=0.05 
0.0002 = 0.1 
. 0003 = 0.15 


0.0012 = 0.6 
0.0013 = 0.65 
0.0014=0.7 


1 








1.4711 


73 


0.0001 = 0.0 


0.0015 = 0.55 


1.3800 


30 


0.0004=0.2 


0.0015 = 0.75 


1-4736 


74 


0.0002 = 0.05 


0.0016 = 0.6 


1.381S 


31 


0.0005 = 0.25 


0.0016 = 0.8 


i I-4761 


75 


0.0003 = 0.1 


0.0017 = 0.65 


1-3836 


32 


0.0006 = 0.3 


0.0017 = 0.85 


: 1.4786 


76 


0.0004 = 0.15 


0.0018 = 0.65 


1-3854 


ZZ 


0.0007 = 0.35 


0.0018 = 0.9 


1.4811 


77 


0.0005 = 0.2 


0.0019 = 0.7 


1.3872 


34 


0.0008 = 0.45 


0.0019 = 0.95 


1 1-4836 


78 


0.0006 = 0.2 


0.0020=0.75 


1.3890 


35 


0.0009 = 0.4 


0.0020=1.0 


' 1.4862 


79 


0.0007 = 0.25 0.0021 = 0.8 


1.3909 


36 


0.0010 = 0.5 


0.0021 = 1.0 


1.4888 


80 


0.0008 = 0.3 io. 0022 = 0. 8 


1.3928 


37 


0.0011 = 0.55 




I. 4914 


81 


0.0009=0.35 0.0023 = 0.85 


1-3947 


38 






1.4940 


82 


0.0010 = 0.3 5 0.0024 = 0.9 


1.3966 


39 






1.4966 


83 


0.0011 = 0.4 0.0025 = 0.9 


1.3984 


40 






1.4992 


84 


0.0012 = 0.45 0.0026 = 0.95 


1.4003 


41 






I. 5019 


85 


0.0013 = 0.5 10.0027=1.0 










I 1-5046 


86 


0014=0.5 


0.0028= 1.0 










' 1-5073 


87 
















1.4023 


42 


0.0001 = 0.05 


0.0012 = 0.6 


t I. 5100 


88 






1-4043 


43 


0.0002 = 0.1 


0.0013 = 0.65 


1-5127 


89 






1.4063 


44 


. 0003 = 0.15 


0.0014 = 0.7 


I -5155 


90 







* Intern. Sugar Jour., 10, pp. 69-70. 

t Find in the table the refractive index which is next lower than the reading actually made 
and note the corresponding whole number for the per cent of dry substance. Subtract the refractive 
index obtained from the table from the observed reading; the decimal corresponding to this 
difference, as given in the column so marked, is added to the whole per cent of dry substance as 
first obtained. 



6i6 



FOOD INSPECTION AND ANALYSIS. 



TEMPERATURE 


CORRECTIONS 


FOR 


USE 


WITH GEERLIGS'S TABLE. 


Tempera- 


Dry Substance. 


ture of the 
Prisms in 


1 5 


10 15 1 20 


25 1 30 1 40 1 50 1 60 1 70 1 


80 1 90 


= C. 


Subtract — 


20 


0.53 


0.54 


0-55 


0.56 


o^57 


0.58 


0.60 


0.62 


0.64 


0.62 


0.61 0. 


60 


0.58 


21 


.46 


-47 


.4« 


■49 


-50 


-51 


•52 


-54 


-56 


-54 


-53 - 


52 


-50 


22 


.40 


-41 


-42 


.42 


•43 


.44 


•45 


-47 


.48 


-47 


.46 . 


45 


-44 


23 


•^^ 


•33 


■34 


-35 


-3C 


.37 


-3« 


-39 


.40 


•39 


■ 38 . 


38 


-38 


24 


.26 


.26 


-27 


.28 


.28 


•29 


•30 


-31 


•32 


•31 


■31 ■ 


30 


-30 


i'S 


.20 


.20 


.21 


.21 


.22 


.22 


-23 


•23 


-24 


•23 


■23 • 


23 


.22 


26 


.12 


.12 


■13 


.14 


.14 


■15 


•15 


.16 


.16 


.16 


■15 ■ 


15 


-14 


27 


.07 


.07 


.07 


.07 


.07 


.07 


.08 


.08 


.08 


.08 


.08 


08 


.07 




Add— 


29 


0.07 


0.07 


0.07 


0.07 


0.07 


0.07 


0.08 


0.08 


0.08 


0.08 


0.08 


08 


0.07 


30 


.12 


.12 


-13 


.14 


.14 


.14 


-15 


•15 


.16 


.16 


.16 


15 


•14 


31 


.20 


.20 


.21 


.21 


.22 


.22 


-23 


-23 


-24 


•23 


-23 


23 


. 22 


32 


.26 


.25 


.27 


.28 


.28 


•29 


-30 


-31 


■32 


-31 


■31 


30 


-30 


33 


-33 


-33 


-34 


-35 


.3b 


-37 


-3« 


-39 


.40 


-39 


■38 


38 


-38 


34 


.40 


.41 


.42 


.42 


•43 


• 44 


-45 


■47 


-48 


-47 


.46 


45 


-44 


35 


.46 


■47 


-48 


■ 49 


■50 


•51 


-52 


■54 


■5b 


■54 


■ 53 


52 


-50 



dark-colored molasses 20 to 30 cc. of lead subacetate are required for 
clarification and in extreme cases (though rarely with the grades of molasses 
used as food) it is necessary, after the ordinary filtration, to pass through 
from 5 to 6 grams of powdered, dried bone charcoal.* 

An excess of subacetate of lead should be avoided on account of the 
possibility of the filtrate becoming turbid through the formation of lead 
carbonate by exposure to the air. A drop of acetic acid will nearly always 
clear the solution, if the turbidity is due to carbonate. If cloudiness in 
the filtrate persists, weigh out a fresh portion of the sample, dilute, and 
add first the lead subacetate solution, and afterwards enough of a strong 
solution of sodium sulphate or common salt to precipitate the excess of 
lead; then fill to the mark and filter. Polarize, and conduct the inver- 
sion as directed on p. 588, using, however, a loo-mm. tube, and multi- 
plying the reading by 2, both direct and invert.f Use Clerget's formula 
for calculation of the sucrose. 

For medium- or light-colored grades of molasses, which yield but 
a small precipitate with lead subacetate, the above method of simple 
polarization, both direct and invert, gives results sufficiently accurate for 
ordinary work. For dark-colored, or "black-strap" molasses, or wherever 

* The treatment with bone char should be used only as a last resort, as, on account of 
slight absorption of sugar, observed readings are from 0.4° to to 0.5° too low. 

t The short tube (100 mm.) is preferred fci polarizing molasses, not only on account of 
the more or less deep color of the clarified solution, but also because a molasses sample con. 
taining considerable commercial glucose would not read within the scale limits, if the 200-mm- 
tube were employed. 



SUGAR AND SACCHARINE PRODUCTS. 



617 



RELATION OF BRIX, SPECIFIC GRAVITY, AND BAUME. 



Per 






Per 






Per 




11 


Per 




S3 

Ecca 


Cent 


Specific 


£§ 


Cent 


Specific 


Cent 


Specific 


Cent 


Specific 


of 


Gravity. 


M (3 


of 


Gravity. 


OJCQ 


of 


Gravity. 


tots 


of 


Gravity. 


Sugar. 




Sugar. 




Sugar. 




Sugar. 




0.1 


I . 0003 


0.06 


6.6 


I .0261 


3-7 


13-1 


1.0531 


7-3 


19.6 


1.081S 


10.8s 


0. 2 


I .0007 


0. 1 1 


6.7 


1 .0265 


3-7 


13-2 


1.0536 


7.3 


19.7 


1 .0819 


10.9 


0.3 


1 .001 1 


0.17 


6.8 


I .0269 


3.8 


13-3 


I .0540 


7-4 


19.8 


1.0824 


II .0 


0.4 


I .0015 


. 22 


6.9 


1.0273 


3-8 


134 


10544 


7-4 


19.9 


1 .0828 


11 .0 


o.S 


1 .0019 


0.28 


7.0 


1.0277 


3.9 


13-5 


1 .0548 


7-5 


20.0 


1.0832 


11 . 1 


0.6 


1.0023 


0.33 


7.1 


1 .0281 


3-9 


13.6 


1-05S3 


7-5 


20.1 


1.0837 


II . 1 


0.7 


I .0027 


0.39 


7.2 


1.0286 


4.0 


13-7 


1-05S7 


7.6 


20. 2 


1 .0841 


11.2 


0.8 


I .0031 


0.44 


7-3 


1 .0290 


4.1 


13.8 


1 -0561 


7.65 


20.3 


I .0846 


11.2 


0.9 


I .0034 


0.5 


7-4 


1 .0294 


4.1 


13-9 


1 .0566 


7-7 


20.4 


I .0850 


11.3 


1 .0 


I .0038 


0.5S 


7-5 


I .0298 


4-2 


14-0 


1.0570 


7-8 


20. s 


1.0855 


11.3 


1 . 1 


1 . 0042 


0.6 


7.6 


1 .0302 


4-2 


14.1 


1-OS74 


7.8 


20. 6 


1-0859 


11.4 


1.2 


1 .0046 


0.7 


7 7 


I .0306 


4.3 


14.2 


1-0578 


7-9 


20.7 


1.0864 


II. 4S 


1.3 


I .0050 


0.7 


7-8 


1.0310 


4-3 


14-3 


1.0583 


7.9 


20.8 


1.0868 


11. 5 


1-4 


I .0054 


0.8 


7-9 


1.0314 


4.4 


14.4 


1.0587 


8.0 


20.9 


1.0873 


11.6 


1.5 


I .0058 


0.8 


8.0 


1 .0318 


4.4 


14-5 


1.0591 


8.0 


21 .0 


1.0877 


II. 6 


1.6 


I .0062 


0.9 


8.1 


1 .0322 


4-5 


14.6 


I .0596 


8.1 


21.1 


1.0882 


II. 7 


1.7 


I .0066 


0.9 


8.2 


1.0327 


4-55 


14.7 


1 .0600 


8.15 


21 . 2 


1.0886 


11.7 


1.8 


I .0070 


1 .0 


8.3 


1.0331 


4.6 


14.8 


I .0604 


8.2 


21.3 


I .0891 


II. 8 


1.9 


1 .0074 


I. OS 


8.4 


1-0335 


4-7 


14.9 


I .0609 


8.3 


21.4 


1-0895 


11.8 


2.0 


1.0077 


1 . 1 


8.5 


1.0339 


4-7 


15.0 


I .0613 


8.3 


21. S 


I .0900 


II. 9 


2. 1 


I .0081 


1 . 2 


8.6 


1.0343 


4.8 


15.1 


1 .0617 


8.4 


21.6 


1.0904 


11.9s 


2. 2 


I .00S5 


1 . 2 


8.7 


I .0347 


4.8 


15.2 


I .0621 


8.4 


21.7 


1 .0909 


12.0 


2-3 


I .0089 


1.3 


8.8 


1.0351 


4.9 


15-3 


I .0626 


8.5 


21.8 


1.0914 


1 2. OS 


2-4 


I .0093 


1.3 


8.9 


1-035S 


4.9 


15.4 


1 .0630 


8.5 


21 .9 


1 .0918 


12. 1 


2.S 


I .0097 


1.4 


9.0 


1.0359 


5-0 


15-5 


1.0634 


8.6 


22 .0 


1.0923 


12.2 


2.6 


I .0101 


1.4 


9.1 


1 .0364 


5.05 


15-6 


1.0639 


8.6s 


22. 1 


1.0927 


12.2 


2.7 


I .0105 


1-5 


9-2 


1.0368 


5-1 


iS-7 


1.0643 


8.7 


22. 2 


1.0932 


12.3 


2.8 


I .0109 


I. 55 


9-3 


1.0372 


5-2 


15-8 


1 .0647 


8.8 


22.3 


1.0936 


12.3 


2.9 


I .0113 


1.6 


9.4 


1.0376 


5-2 


15-9 


1 .0652 


8.8 


22.4 


1.0941 


12.4 


3.0 


1 .0117 


1.7 


9-5 


1 .0380 


S.i 


16.0 


1 .0656 


8.9 


22.5 


1.0945 


12.4 


3-1 


1 .0121 


1-7 


9.6 


I .0384 


5-3 


16.1 


1 .0660 


8.9 


22.6 


1.0950 


12. 5 


3.2 


1 .0125 


1.8 


9-7 


1.0388 


5-4 


16.2 


1.0665 


9.0 


22.7 


1.0954 


12. SS 


i-i 


I .0129 


1.8 


9.8 


I .0393 


5-4 


16.3 


1 .0669 


9.0 


22.8 


1.0959 


12.6 


3.4 


1. 0133 


1.9 


9.9 


1.0397 


5-5 


16.4 


1 .0674 


9.1 


22.9 


1.0964 


12.7 


3-5 


I. 0137 


1.9 


10.0 


1 .0401 


5-SS 


16. 5 


1.0678 


9.1 


23.0 


1.0968 


12.7 


3.6 


t .0141 


2.0 


1 10.1 


1 .0405 


5-6 


16.6 


1.0682 


9.2 


23-1 


1-0973 


12.8 


3-7 


1.0145 


2.0 


10. 2 


1 . 0409 


5.7 


16.7 


1.0687 


9-25 


23-2 


1.0977 


12.8 


3.8 


1 .0149 


2.1 


10.3 


1.0413 


5-7 


16.8 


I .0691 


9-3 


23-3 


I .0982 


12.9 


3.9 


I-OI53 


2. 2 


10.4 


1 .0418 


5-8 


16.9 


I .0695 


9.4 


23-4 


1.0986 


12.9 


4.0 


I.01S7 


2.2 


10. 5 


I .0422 


5.8 


17.0 


1 .0700 


9.4 


23-S 


I. 0991 


13-0 


4.1 


I .oi6i 


2.3 


10.6 


1 .0426 


5-9 


17-1 


1 .0704 


95 


23.6 


1 .0996 


13-0 


4-2 


1.0165 


2.3 


10.7 


1.0430 


5-9 


17.2 


I .0709 


95 


23.7 


1 . 1000 


13-I 


4-3 


1 .0169 


2.4 


10.8 


1.0434 


6.0 


17-3 


I-0713 


9.6 


23.8 


I .1005 


13. IS 


4-4 


1.0173 


2.4 


10.9 


1.0439 


6.05 


17.4 


I. 0717 


9.6 


23-9 


1 . 1009 


13-2 


4-S 


1.0177 


2.5 


11.0 


1-0443 


6.1 


17-S 


I .0722 


9-7 


24.0 


I .1014 


13-3 


4.6 


I .0181 


2.6 


11 . 1 


1.0447 


6.2 


17.6 


I .0726 


9-75 


24. 1 


I . 1019 


13-3 


4-7 


1.0185 


2.6 


11.2 


1.0451 


6.2 


177 


1.0730 


9.8 


24.2 


1.1023 


13.4 


4.8 


I .0189 


2.7 


11-3 


I -0455 


6.3 


17.8 


1.0735 


9-9 


24-3 


I. 1028 


13-4 


4.9 


1.0193 


2.7 


11.4 


I -0459 


6.3 


17.9 


1 .0739 


9.9 


24.4 


1.1032 


13-S 


5.0 


1.0197 


2.8 


ii-S 


I .0464 


6.4 


18.0 


1-0744 


10. 


24-5 


I-I057 


13.5 


s.-i- 


t .0201 


2.8 


11.6 


1 .0468 


6.4 


18.1 


1 .0748 


10.0 


24.6 


I. 1042 


13-6 


5-2 


1.0205 


2.9 


11.7 


1.0472 


6.5 


18.2 


1-0753 


10. 1 


24-7 


1 . 1046 


13-6 


5-3 


I .0209 


2.9 


11.8 


1 .0476 


6.55 


18.3 


1.0757 


10. 1 


24.8 


I. 1051 


13.7 


5-4 


t.0213 


3.0 


II. 9 


1 .0481 


6.6 


18.4 


I .0761 


10. 2 


24.9 


1.1056 


13.7s 


5-5 


t .0217 


3.0 


12.0 


I .0485 


6.7 


18.5 


I .0766 


10. 2 


25.0 


I . 1060 


13.8 


S.6 


t .0221 


3.1 


12.1 


1 . 0489 


6.7 


18.6 


1.0770 


10-3 


25-1 


1.1065 


13.9 


5.7 


I. 022s 


3.2 


12.2 


I -0493 


6.8 


18.7 


1.0775 


10.35 


25.2 


1 . 1070 


13.9 


S.8 


1 .0229 


3.2 


12.3 


1.0497 


6.8 


18.8 


1.0779 


10.4 


25.3 


1.1074 


14.0 


5-9 


1.0233 


3-3 


12.4 


1.0502 


6.9 


18.9 


1.0783 


10.5 


25.4 


1.1079 


14.0 


6.0 


1.0237 


3-i 


12. s 


I .0506 


6.9 


19.0 


1.0788 


10.5 


25-5 


1.1083 


14.1 


6.1 


1.0241 


3.4 


12.6 


1.0510 


7.0 


19.1 


1.0792 


10. 6 


25-6 


i.io88 


14. 1 


6.2 


1.024s 


3-4 


12.7 


1.0514 


7.05 


19.2 


1.0797 


10.6 


25.7 


1.1093 


14.2 


6.3 


1 .0249 


3-5 


12.8 


1.0519 


7-1 


19-3 


1 .0801 


10.7 


25.8 


1.1097 


14-2 


6.4 


I-0253 


3.6 


12.9 


1-0523 


7.2 


19.4 


I .0806 


10.7 


25-9 


I . 1102 


14-3 


6.5 


1.0257 


3.6 


13.0 


1.0527 


7.2 


19. S 


1 .0810 


10.8 


: 26.0 


1 . 1107 


14.3s 



6i8 



FOOD INSPECTION AND ANALYSIS. 



RELATION OF 


BRIX, 


SPECIFIC GR.WITY, .\ND 


BAUME— (C 


ontinned). 


Per 


\ 
1 


1% ' 


Per 


«~£ 


Per 




-4) 

c 


Per 


\ 


■«) 


Cent 


Specific 


Cent Specific 


fei 


Cent 


Specific 


S3 


Cent 


Specific 


of 


GraN^ty. 


l« 1 


of Gra\-ity. 


aoc4 
17.9 


of 


Gra^-ity. 


so si 


of 


Gravity. 


accit 


Sugar. 




Sugar. 


Sugar. 




Siagar. 


» 


»6.i 


I .IITI 


14-4 


32.6 1.1422 


39.1 


1.1748 


21.4 


45-6 


I . 2088 


24.9 


26. 2 


I . m6 


14-5 


32.7 1.1427 


18.0 


39-2 


1-1753 


21.5 


45-7 


1.2093 


24-9 


26.3 


I . II21 


14-5 


32.8 1.1432 


iS.o 


39-3 


1-1758 1 


21.5 


45-8 


1 . 2099 


25.0 


26.4 


1 . I I2S 


14.6 1 


32.9 1.1437 


iS.i 


39-4 


1.1763 


21 .6 


45 9 


1. 2104 


25.0 


26.5 


1.H30 


14.6 1 


33-0 


1.1442 


1S.15 


39-5 


1.1768 


21.6 


46.0 


I .2110 


25-1 


26.6 


1.H3S 


14.7 ' 


33-1 


1.1447 


18.2 


39-6 


1.1773 


ai.7 


46.1 


1.2115 


25.1 


26. 7 


1 . 1 1 40 


14-7 


33-2 


1.1452 


18.25 


39-7 


1.177S 


21.7 


46. 2 


I . 2iao 


25.2 


26. S 


1.II44 


14.8 


33-3 1 


1.1457 


18.3 


39-8 


1.1784 


21.8 


46.3 


1 .3126 


25.2 


26.9 


I.H49 


14. S 


33-4 


1 .1462 


18.4 


39-9 


1.1789 


21.85 


46.4 


1 .2131 


25-3 


27.0 


1-1154 


14.9 


33-5 ; 1.1466 1 


1S.4 


40.0 


1.1794 


21.9 


46. S 


1 . 2136 


25.35 


27.1 


1.1158 


14-9 


33-6 


1.1471 


1S.5 


40.1 


1.1799 


23. 


46.6 


1.2143 


25.4 


27.2 


1 . 1163 


15-0 


33-7 


1.1476 


18.5 


40.2 


1 . 1804 


22.0 


46.7 


1.2147 


25-43 


27-3 


1.1 168 


15-1 


33-8 


1 .1481 


iS.6 


40.3 


1 . 1 809 


23.1 


46. 8 


1.2153 


25-S 


27.4 


1 .1172 


15-1 


33.9 


1 . 14S6 


18.6 


40.4 


1.1815 


22.1 


46.9 


1.2158 


25.6 


27-5 


1.1177 


15.2 


340 


1.1491 


1S.7 


40.5 


1.1820 


23.2 


47.0 


1.2163 


25.6 


27.6 


1.1182 


15. a 


34.1 H406 


i8.7 


40.6 


1.1825 


22.2 


47-1 


1 . 2169 


25-7 


27.7 


1.1187 


15-3 ! 


34.2 , 1.1501 


iS.8 


40.7 


1.1830 


22.3 


47-2 


1.2174 


25 -7 


27. s 


1 . H9i 


15-3 


34-3 1 


1 .1506 


18.85 


40.8 


1.1835 


22.3 


47.3 


1 . 2 1 80 


25.8 


27.9 


1 . 1196 


15-4 


34-4 


1.1511 


iS.9 


40.9 


I. 1840 


22.4 


47-4 


1.2185 


35.8 


28.0 


I .1201 


15-4 


34-5 


1 .1516 


18.9s 


41. 


1.1S46 


22.4 


47-5 


1 .2191 


35.9 


28.1 


1 . 1 206 


IS-S 


34-6 


1.1521 


19-0 


41-1 


1.1851 


aa.s 


47-6 


1 .3196 


25-9 


28. a 


1 .12IO 


15-55 


34-7 


1.1526 


19-1 


41.2 


1.1856 


22.5 


47-7 


1.2201 


26.0 


28.3 


1.1215 


15-6 


34-8 


1.1531 


19-1 


41-3 


1.1861 


22.6 


47-8 


1 . 2207 


26.0 


28.4 


1 .1220 


15-7 


34-9 


1-1536 


19-3 


41-4 


1.1866 


23.65 


47.9 


1 .2212 


26.1 


28.5 


1.1225 


15-7 


SS-o 


1-1541 


19-2 


41-5 


1.187a 


22.7 


48. 


1.2218 


26.1 


28.6 


I .1229 


15-8 


35-1 


1.1546 


19-3 


41.6 


1.1877 


22-75 


48.1 


I .2223 


26.2 


28.7 


1.1234 


15-8 


35-2 


1.1551 


19-3 


41-7 


1.1883 


22.8 


48. 2 


I .2229 


26.3 


28.8 


1.1239 


15-9 


35-3 


1-1556 


19.4 


41-8 


1.1887 


22.9 


48.3 


1.3234 


26.3 


28.9 


1 - 1 244 


15-9 


35-4 1 1.1561 


19.4 


41-9 


i.i8oa 


22.9 


48. 4 


1 .3340 


36.33 


29.0 


1 . I 248 


16.0 


33-5 


1.1566 


19-5 


43-0 


1.1898 


23.0 


48.5 


1.3345 


36.4 


29.1 


I. 1253 


16.0 


35x6 


1.1571 


19-55 


42.1 


1.1903 


23.0 


48.6 


1.2250 


36.45 


29.2 


1.1258 


16.1 


3S-7 


1.1576 


19.6 


43.2 


1 . 1908 


23-1 


48.7 


1.2256 


36. 5 


29.3 


1.1263 


16.1 


35-S 


1.1581 


19.65 


42.3 


1.1913 


23-1 


48.8 


1 .2261 


26.6 


29.4 


1.1267 


16.2 


35-9 


1.1586 


19-7 


42.4 


1.1919 


23.2 


48.9 


1.2267 


26.6 


29. 5 


1.1272 


16.23 


36.0 


1.1591 


19. 8 


42-3 


1.1924 


23.3 


49-0 


1.2272 


26.7 


29.6 


1-1277 


16.3 


36.1 


1.1596 


19-8 


42.6 


1.1929 


33-3 


49- 1 


1.2278 


26.7 


29.7 


1.1282 


16.4 


36.2 


1 .1601 


19.9 


42.7 


1-1934 


23-3 


49-2 


1.2283 


20.8 


29.8 


1.1287 


16.4 


36.3 


1.1606 


19.9 


42.8 


1 .1940 


33.4 


,49.3 


1.2289 


26.8 


29.9 


1.1291 


16.5 


36.4 


1 .i6ii 


20.0 


42.9 


1.1945 


23-45 


; 49-4 


1.2294 


26.9 


30.0 


1.1296 


i6.s 


36.5 


1 .1616 


20.0 


43-0 


1-1950 


23-5 


49-5 


1 . 2300 


26.9 


30.1 


1.1301 


i6.6 


36.6 


1.1621 


20.1 


43-1 


1.1955 


23-55 


49-6 


1-3305 


27-0 


30.2 


1.1306 


16.6 


36. T 


1.1626 


20.1 


43-2 


1.1961 


23.6 


49-7 


1 .2311 


27.0 


30 -3 


1.1311 


16.7 


36.8 


1.1631 


20.2 


43-3 


1 .1966 


23-7 


49.8 


1.2316 


37.1 


30-4 


1.1315 


16.7 


36.9 


1 .1636 


20.2 


43-4 


1.1971 


23-7 


49-9 


1 .2322 


27.1 


30.5 


1.1320 


16.8 


37.0 


1.1641 


20.3 


43-5 


I. 1976 


23.8 


50.0 


1-2327 


27. a 


30.6 


1.1323 


1 16.85 


3T-X 


I. 1646 


ao.35 


45.6 


1.1982 


23-8 


50.1 


1-2333 


37 .3 


30- 7 


1.1330 


16.9 


3T.a 


1.1651 


ao.4 


43. T 


1.1987 


23.9 


50.2 


1-233S 


27-3 


30.8 


X-1335 


17-0 


37.3 


1.1656 


20.5 


43-8 


1.1992 


23-9 


50.3 


1-2344 


27-3 


30 -9 


1.1340 


17.0 


37-4 


I .1661 


20.3 


43-9 


1 .1998 


34.0 


SO. 4 


1 - 2349 


27.4 


31.0 


1.1344 


17-1 


37-S 


1.1666 


1 20.6 


44-0 


i..:oj3 


34.0 


50.5 


1-2353 


27-43 


31.1 


1.1349 


iT-i 


37-6 


1.1671 


1 20.6 


44-1 


1 . 2008 


24.1 


50.6 


1.2361 


27 -5 


3t.2 


1-1354 


17.2 


3?-7 


1.1676 


1 20.7 


44-2 


1.2013 


34.1 


50.7 


1 . 2366 


27-SS 


31.3 


1.1359 


17.2 


37-8 


t.i68t 


20.7 


44-3 


1 .2019 


34.2 


50.8 


1-2372 


27.6 


31-4 


1-1364 


17.3 


37-9 


1.1686 


20.8 


44-4 


1 .2024 


24.2 


50.9 


1-2377 


27-7 


31.3 


1.1369 


17-3 


38. 


1.1692 


20.8 


44-5 


1 .2029 


24-3 


5t-0 


1-3383 


27-7 


31.6 


1-1374 


17-4 


38-1 


1.1697 


20.9 


44-6 


1.203s 


24-35 


51.1 


1.3388 


27.8 


31-7 


1-1378 


17.4 


38. 2 


1.1702 


20.9 


44-7 


I . 2040 


24.4 


1 51.2 


I • 2394 


27.8 


31.8 


1-1385 


17-5 


3S-3 


1.1707 


21. 


44-8 


I . 3045 


34-45 


1 51-3 


1-2399 


27.9 


31-9 


1.1388 


17-55 


38.4 


1 .1712 


21.05 


44.9 


1 .3051 


24-5 


Si-4 


1 . 2405 


27-9 


32. 


1.1393 


17-6 


38. 5 


1.1717 


21. 1 


45 -o 


1 . 3056 


24.6 


51-5 


1 .2411 


38.0 


32.1 


1.1398 


17-7 


38.6 


1.1722 


21.15 


431 


1.2061 


24.6 


51-6 


1.3416 


38. 


32.2 


1.1403 


17.7 


38.7 


1.1727 


21.2 


45-2 


I . 2067 


34.7 


51-7 


1.2422 


38.1 


33.3 


I . 140S 


17.8 


38. S 


1.1733 


21.3 


45-3 


1 .S072 


24-7 


51.8 


1-2427 


28. 1 


32-4. 


1.1412 


17.8 


38.9 


1-1737 


21.3 


45-4 


1.2077 


24. 8 


51-9 


1 ■ 2433 


38. a 


32.5 


1.1417 


17.9 


39 -o 


1-1743 


21.4 


43-5 


1.2083 


24.8 


52.0 


I . 2439 


28. a 



SUGAR AND SACCHARINE PRODUCTS. 



619 



RELATION OF BRIX, SPECIFIC GRAVITY, AND B.WME— {Continued). 



Per 


1 




Per 






Per 




to 


Per 




-«3 


Cent 


Specific ' 


£5 


Cent 


Specific 


t^ 


Cent 


Specific 


Cent 


Specific 


°^ 


Gravity. 


0" 


of 


Gravity. 


GJCQ 


of 


Gravity. 


00 OS 


of 


Gravity- 


Siigar. 


1 


Sugar. 


or 


Sugar. 




Sugar. 




52.1 1 


I . 2444 


28.3 


S8.6 


I. 2816 


31.6 


65.1 


1.3205 


34-95 


71.6 


I . 3610 


38.2 


52.2 \ 


1.2450 


28.3 


58.7 


X.2822 


31.7 


65.2 


1 .3211 


35-0 


71.7 


1 .361 J 


38.2 


S2.3 ! 


I. 2455 


28.4 


58.8 


I.2'!?8 


31-7 


65.3 


1.3217 


35.0s 


71.8 


1-3623 


38.2 


52-4 


I . 2461 


28.4 


58.9 


I . 2*^ -54 


31-8 


6S-4 


1-3223 


35-1 


71.9 


1 . 3629 


38.3 


S2-5 


1 . 2467 


28.5 


S9-0 


I.2«42 


31-85 


6S.S 


1.3229 


35.15 


72.0 


1-3635 


38.3 


52-6 


1.2472 


28. s 


S9-I 


1.2845 


31.9 


65.6 


1.323s 


35-2 


72.1 


1.3642 


38.4 


52.7 


I .2478 


28.6 


59.2 


1.2851 


31-95 


65.7 


1.3241 


35-25 


72.2 


1.3648 


38.4 


52. 8 


1.2483 


28.65 


59-3 


1-2857 


32.0 


65.8 1 


1.3247 


35-3 1 


72.3 


1.3655 


38.5 


52.9 


1.2489 


28.7 


59-4 


1.2863 


32.05 


65.9 ' 


1-3253 


35.35 


72.4 


I .3661 


38. 5 


53.0 


I -2495 


28.75 


S9-S 


I . 2869 


32.1 


66.0 


I -3260 


35.4 


72.5 


1-3667 


38.6 


S3. 1 


1 . 2500 


28.8 


S9-6 


1-2875 


32.15 


66.1 


I . 3266 


35.4 


72.6 


1-3674 


38.6 


53.2 


1 . 2506 


28.85 


59-7 


I. 2881 


32.2 


66.2 


1.3272 


35. 5 


72.7 


1.3680 


38.7 


53.3 


I . 2512 


28.9 


59-8 


1.2887 


32.3 


66.3 


1.3278 


35.5 


72.8 


1.3687 


38.7 


53.4 


I. 2517 


28.9 


59-9 


1.2893 


32.3 


66.4 


1.328s 


35.6 1 


72-9 


1-3693 


38.8 


53.S 


1.2523 


29.0 


60.0 


1.2898 


32.4 


66.5 


1-3291 


35. 6 


73-0 


1.3699 


38.8 


53.6 


1.2529 


29.1 


60.1 


1.2904 


32.4 


66.6 


1-3297 


35.7 


73.1 


1-3705 


38-9 


53-7 


I. 2534 


29. 1 


60. 2 


1 . 2910 


32.5 


66.7 


1.3303 


35.7 


73.2 


1.3712 


38-9 


53-8 


1.2540 


29.2 


60.3 


1 .2916 


32.5 


66.8 


1-3309 


35.8 


73-3 


1-3719 


39 


53.9 


1.2546 


29. 2 


60.4 


1 . 2922 


32.6 


66.9 


1-3315 


35.8 1 


73.4 


1-3725 


39.0 


S4-0 


I. 2551 


29.3 


60.5 


I .2928 


32.6 , 


67 .0 


1-3322 


35.9 


73.5 


1-3732 


39.1 


54 1 


1-2557 


293 


60.6 


1-2934 


32.7 


67.1 


1-3327 


35.9 


73.6 


1-3738 


39 I 


54-2 


1.2563 


29.4 


60. 7 


I . 2940 


32.7 


67.2 


1.3334 


36.0 1 


73.7 


1-3745 


39-2 


54-3 


1.2568 


29.4 


60.8 


I . 2946 


32.8 


67.3 


1.3340 


36.0 ; 


73.8 


I-375I 


39.2 


54-4 


1.2574 


29. ■- 


60.9 


1.2952 


32.8 


67.4 


I .3346 


36.1 


73-9 


1.3757 


39-3 


54.5 


1.2580 


29.5 


61.0 


1.2958 


32.9 


67-S 


I. 3352 


36.1 I 


74.0 


1-3764 


39.3 


54.6 


1.258s 


29.6 


61.1 


1 . 2964 


32.9 1 


67.6 


1.3359 


36.2 


74-1 


1-3770 


39-4 


54-7 


1-2591 


29.6 


61.2 


1.2970 


33.0 


67-7 


1.336s 


36.2 


74-2 


1-3777 


39.4 


54.8 


I. 2597 


29.7 


61.3 


1.2975 


33.0 1 


67-8 


1.3371 


36.3 


74.3 


1-3783 


39. 5 


54-9 


I .2602 


29.7 


61.4 


I . 2y8i 


331 


67.9 


1.3377 


36.3 


74.4 


1-3790 


39-5 


55. 


I . 2608 


29.8 


61. s 


1.2987 


33.1 


68.0 


1.3384 


36.4 


74. 5 


1-3796 


39-6 


55. 1 


I . 2614 


29.8 


61.6 


1-2993 


33.2 


68.1 


1.3390 


36.4 


74-6 


1-3803 


39-6 


55-2 


I . 2620 


29.9 


61.7 


I . 2999 


33.2 


68.2 


1.3396 


36.5 


74.7 


I . 3809 


39-7 


55-3 


I .2625 


29.9 


61.8 


1.3005 


33-3 


68.3 


1.3402 


36.5 


74.8 


I. 3816 


39.7 


55-4 


1.2631 


30.0 


61 .9 


1.3011 


33-3 


68.4 


I . 3408 


36.6 


74.9 


1.3822 


39-8 


5S-S 


1.2637 


30.05 


62.0 


I. 301 7 


33-4 


68.5 


1.3415 


36.6 


75.0 


1.3828 


39-8 


55-6 


I . 2642 


30.1 


62.1 


1-3023 


33-4 


68.6 


I. 3421 


36.7 


75. 1 


1.383s 


39-9 


55-7 


I . 2648 


30.15 


62.2 


1.3029 


33-S 


68.7. 


1.3427 


36.7 


75.2 


1.3842 


39-9 


SS.8 


1-2654 


30.2 


62.3 


1-3035 


33.5 


68.8 


1.3433 


36.8 


75-3 


1.3848 


40 . 


55-9 


1 .2660 


30.25 


62.4 


1-3040 


33-6 


68.9 


I . 3440 


36.8 I 


75-4 


1.385s 


40.0 


56.0 


1 . 2665 


30.3 


62.5 


1 - 3047 


33-6 


69.0 


I . 3446 


36.9 


75-5 


I. 3861 


40.1 


56.1 


I. 267 1 


30.4 


62.6 


1.3053 


33.7 


69.1 


1.3452 


36.9 ' 


75.6 


1.3868 


40.1 


56. 2 


1.2677 


30.4 


62.7 


1-3059 


33-7 


69 2 


1.3458 


37-0 1 


75.7 


1.3874 


40.2 


S6.3 


1.2683 


30.5 


62. a 


1.3065 


33-8 


69 3 


I . 3465 


37-0 1 


75-8 


1.3880 


40.2 


56.4 


1.2688 


30. s 


62.9 


1 - 3071 


33-8 


69-4 


1-3471 


37.1 


75.9 


1.3887 


40.3 


56.5 


1.2694 


30.6 


63.0 


1-3077 


33-9 


69-S 


1-3477 


37-1 


76.0 


1 . 3894 


40.3 


56.6 


1.2700 


30.6 


63-1 


1 .3083 


33-9 


' 69-6 


I - 3484 


37-2 


76.1 


I . 3900 


40-4 


56. 7 


I . 2706 


30-7 


63.2 


I .3089 


34-0 


69.7 


I . 3490 


37.2 


76. 2 


1-3907 


40.4 


56.8 


1.2712 


30.7 


63-3 


1-3095 


34 


: 69-8 


I . 3496 


37-3 


76.3 


1-3913 


40. S 


S6.9 


1 -2717 


30.8 


63-4 


1 . 3101 


34-1 


i 69.9 


1.3502 


37-3 


76.4 


1.3920 


40. s 


57-0 


1.2723 


30.8 


63-5 


1-3107 


34-1 


, 70-0 


1.3509 


37-4 


76.5 


1-3926 


40.6 


57. 1 


1.2729 


30.9 


63.6 


1-3113 


34-2 


1 

70.1 


I-351S 


37-4 ' 


76.6 


1.3933 


40.6 


57-2 


1.2735 


30.9 


63-7 


1.3119 


34-2 


70.2 


I-3521 


37.5 


76.7 


1 - 3940 


40.7 


57.3 


I . 2740 


31.0 


63-8 


I. 3126 


34-3 


70.3 


1-3528 


37-5 


76.8 


1-3946 


40.7 


57.4 


1.2746 


31.0 


63 -9 


1-3132 


34-3 


70.4 


1-35 34 


37-6 


76.9 


1-3953 


40. 8 


57-5 


1.2752 


31-1 


64.0 


1-3138 


34-4 


70. s 


1.3540 


37-6 


77.0 


1.3959 


40.8 


57-0 


1-2758 


3I-I 


64.1 


1-3144 


34-4 


70.6 


1-3546 


37.7 


77-1 


1 . 5966 


40. 8 


57-7 


1.2764 


31-2 


64. 2 


1-3150 


34-5 


70.7 


V3553 


37-7 


77-2 


1-3972 


40.9 


57.8 


1.2769 


31.2 


64-3 


1-3156 


34- 5 


70.8 


1.3359 


37-8 


77-3 


1.3979 


41.0 


57-9 


1.277s 


31-3 


64.4 


I .3162 


34-6 


70.9 


1.3565 


37.8 


77-4 


1.3986 


41.0 


58.0 


1 .2781 


31-3 


64-5 


1.3168 


34-6 


71.0 


1-3572 


37.9 


77.5 


1-3992 


41-0 


58.1 


1.2787 


31-4 


64.6 


1-3174 


34-7 


71. 1 


1.3578 


37.9 


77-6 


1-3999 


41-1 


58.2 


I-2793 


31-4 


64.7 


1.3180 


34-7 


71-2 


1.358s 


38.0 


77-7 


1 -400; 


41 -I 


58. 3 


I .2799 


31-5 


, 64.8 


I. 3186 


34-8 


71-3 


1.3391 


38.0 


77.8 


I .4012 


41-2 


58.4 


1 .2804 


31. s 


64.9 


1-3192 


34-8 


71-4 


1-3597 


38.1 


77.9 


1 .4019 


41.2 


58.5 


I . 2810 


31.6 


65.0 


I. 3198 


34-9 


71-5 


1 . 3604 


38.1 


78.0 


1.4025 


41.3 



620 



FOOD INSPECTION AND ANALYSIS. 



RELATION OF 


BRIX 


, SPECIFIC GRAVITY, AND "QklJME— {Concluded). 


Per 




413 


Per 




. 
So rt 

42.3 


Per 




'6 


Per 




<u p 


Cent 


Specific 


Cent 


Specific 


Cent 


Specific 


fed 


Cent 


Specific 




of 


Gravity. 


of 


Gravity. 


of 


Gravity. 


of 


Gravity. 


Sugar. 




Sugar. 




Sugar. 




Q 


Sugar. 




Q 


78.1 


I .4032 


80.1 


1.416s 


82.1 


1.4300 


43-3 


84.1 


1-4437 


44-2 


78.2 


I 4039 


41 .4 


80.2 


1-4172 


42.3 


82.2 


1.4307 


43-3 


84.2 


I -4443 


44-3 


78.3 


I .4045 


41 .4 


80.3 


1.4179 


42.4 


82.3 


1.4314 


43-4 


84-3 


1-4450 


44-3 


78.4 


1.4052 


41-5 


80.4 


1.418s 


42.4 


82.4 


1.4320 


43-4 


84.4 


1-445 7 


44-3 


78. 5 


1 .4058 


4I-S 


80. s 


I. 4192 


42-5 


82. s 


1.4327 


43-5 


84-5 


I -4464 


44.4 


78.6 


1 .4065 


41 .6 


80.6 


1-4199 


42-5 


82.6 


1.4334 


43-5 


84.6 


I. 4471 


44-4 


78.7 


I .4072 


41 . 6 


80.7 


1-420S 


42.6 


82.7 


I -4341 


43-5 


84-7 


1.4478 


44-5 


78.8 


I .4078 


41 .7 


80.8 


I .4212 


42.6 


82.8 


I -4348 


43-6 


84-8 


1.4485 


44. S 


78.9 


I .4085 


41 -7 


80.9 


I. 4219 


42.7 


82.9 


I -4354 


43-6 


84.9 


I -4492 


44.6 


79.0 


I .4092 


41.8 


81.0 


I .4226 


42.7 


83.0 


I. 4361 


43-7 


85.0 


I .4498 


44-6 


79 I 


I .4098 


41.8 


81. 1 


1.4232 


428 


83.1 


l.43''8 


43.7 


85.1 


I -4505 


44.7 


79.2 


I .410S 


41.9 


81.2 


I .4239 


42.8 


83.2 


1-4375 


43-8 


85.2 


I -4512 


44-7 


19} 


I .41 12 


41.9 


81.3 


I .4246 


42.0 


83.3 


1.4382 


43.8 


8s-3 


1.4519 


44-8 


79 4 


1.4119 


42 .0 


81.4 


1-4253 


42.9 


83.4 


1.4388 


43-9 


8S-4 


1.4526 


44-8 


79-5 


1.4125 


42.0 


81.5 


1.4259 


43.0 


83-S 


1.439s 


43.9 


85-5 


1.4533 


44-9 


79.6 


1.4132 


42.1 


81.6 


I .4266 


43.0 


83-6 


1.4402 


44.0 


85.6 


1.4540 


44-9 


79-7 


I. 4138 


42.1 


81.7 


1.4273 


43.1 


83-7 


1.4409 


44.0 


85-7 


1.4547 


4S-0 


79 8 


I .4145 


42.2 


81.8 


I .4280 


43.1 


83-8 


I .441 6 


44.1 


85.8 


1.4554 


450 


79 9 


I .4152 


42.2 


81 .9 


1.4287 


43-2 


83.9 


1.4423 


44.1 


85-9 


1.4561 


45-1 


80.0 


1.4158 


42.2 


82.0 


1-4293 


43.2 


84.0 


1.4430 


44-2 


86.0 


1-4568 


45-1 



extreme accuracy is required, the double dilution method of Wiley should 
be employed, which makes due allowance for the volume of the pre- 
cipitate. 

Double Dilution Method j^ — Take half the normal weight of the sample 
and make up the solution to 100 cc, using the appropriate clarifier. Take 
the normal weight of the sample and make up a second solution with the 
clarifier to 100 cc. Filter and obtain direct polariscopic readings of 
both solutions. Invert each in the usual manner and obtain the invert 
reading of the two. 

The true direct polarization of the sample is the product of the two 
direct readings divided by their difference. The true invert polariza- 
tion is the product of the two invert readings divided by their difference. 

Determination of Raffinose in Beet Sugar Molasses. — For the deter- 
mination of sucrose and raffinose when present in the same solution, use 
the following formulas of Creydt : f 

0.5188^ — 6 



and 



Sucrose 



Raffinose = 



0.8454 
-S 



1.85' 



(I) 



(2) 



where a=direct reading, 6=reading after inversion, and 5 = per cent 
of sucrose. 



* Wiley and Elwell, Analyst, 1896, 21, p. 184. 

t U. S. Dept. Agric, Bur. of Chem., Bui. 107 (rev.), p. 43. 



SUGAR AND SACCHARINE PRODUCTS. 621 

Davoll * recommends for purposes of clarification of the molasses the 
use of powdered zinc after inversion of the molasses sample according to 
Clerget's method. He adds i gram of the zinc to the sample after in- 
version while at the temperature of 69° C, allowing it to act for three to 
four minutes at that temperature, after which he cools and filters, with 
the production of an almost colorless solution. 

Determination of Reducing Sugar. — {Estimated as Dextrose.) — Dilute 
5 grams of molasses or syrup with water in a loo-cc. graduated flask, 
using 2 to 5 cc. of subacetate of lead solution. Make up to 100 cc, 
filter, take an aliquot part of the filtrate (25 to 50 cc.) and make this 
up to 100 cc, the amount taken being such that, when diluted, the solu- 
tion will contain not more than ^% of dextrose. If lead subacetate has 
been used to clarify, add to the aliquot part taken and before dilution, 
enough sodium sulphate to precipitate the excess of lead, then filter 
and make up to the 100 cc. mark. 

Determine the reducing sugar in this solution by either volumetric 
or gravimetric Fehling processes. 

U. S. Standard Molasses is molasses containing not more than 25% 
of water, nor more than 5% of ash. 

Adulteration of Molasses and Syrups. — A common adulterant of all 
these products is commercial glucose. From its water-white color and 
inert sweetness, no less than from its cheapness, it forms an admirable 
adulterant for dark-colored or low-grade molasses and syrups, counter- 
acting to a great extent by its smoothness the strong and often disagree- 
able taste of the inferior products with which it is mixed. Thus a grade 
of molasses too cheap to be ordinarily used for food purposes can be 
made to assume the appearance, and to some extent the taste, of the 
higher-priced and light-colored grades, by admixture with commercial 
glucose. 

Tin salts are also used to improve the color of low-grade or dark 
molasses, and bleaching agents, such as sulphurous acid, are frequently 
employed. Copper is sometimes found, due to utensils or vessels used 
in processes of manufacture. 

Lead may occur in maple syrup, due to the leaden plugs or spigots 
through which the sap is sometimes drawn from the trees. 

Detection and Determination of Commercial Glucose. f — From the 
direct polarization of a normal solution of molasses or syrup the presence 

* Jour. Am. Chem. Soc, 25 (1903), p. 1019, 
\ Leach, ibid., p. 982. 



62 2 FOOD INSPECTION /IND ANALYSIS. 

or absence of commercial glucose can usually be established. The direct 
polarization of a normal solution of pure molasses should not be much in 
excess of 50° on the Soleil-Ventzke scale, while a pure, dark-colored molas- 
ses should polarize well under 40°. Golden syrup and maple syrup 
read higher than molasses, and a normal solution of pure maple syrup 
may have a direct polarization as high as 65°, being more often than not 
above 60°. 

An excessively high direct polarization is at once an indication of 
the presence of commercial glucose, while an invert reading at ordinary 
room temperature to the right of the zero-point is an almost positive 
proof of its presence in either of the above products. 

The optically active constituents of commercial glucose, viz., dextrin, 
maltose, and dextrose, are present in such varying amounts, that it is 
impossible to determine accurately the exact amount of this adulterant 
in complex saccharine products which themselves contain components 
common to glucose. Its approximate amount can, however, be very 
satisfactorily estimated in molasses and syrups by the use of the follow- 
ing formula: 

175 ' 

where G = per cent of commercial glucose, a = direct polarization, and 
5' = per cent of cane sugar previously obtained from the Clerget formula 
(p. 588). A large amount of invert sugar present affects the accuracy 
of this formula. It is especially applicable to maple syrup, wherein the 
per cent of invert sugar is small, but may be applied also to molasses 
and golden syrup, wherein the amount of invert sugar is not so large 
but that results may be obtained as close as could be expected from an 
empirical formula.f 

In saccharine products containing considerable invert sugar the 
invert reading at 87° C. obtained as directed on page 639, is divided by 

* Leach, U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 48. 

f This formula is based on the assumption that 42° Be. mixing glucose, the grade 
specially made and used for admixture with molasses, syrups, and honey, has a maximum 
polarization of 175° V. It was adopted as a result of investigations made some years ago 
by the author, but subsequently it appeared that 42° Be. mixing glucose polarizes lower 
than formerly. Thus a sample recently examined by the author polarized at 162.4° V. 
Pending further investigations it seems best for the present to retain the old formula, for, 
while it undoubtedly gives low results, especially with higher admixtures of glucose, it 
approximates the truth more closely than would be expected, perhaps because it tends to 
compensate for the error due to substances in genuine molasses and honey that polarize 
to the right after inversion. Furthermore, it has been adopted by the A. O. A. C. To 
avoid misunderstanding, express results in terms of glucose polarizing at that factor. 



SUGAR AND SACCHARINE PRODUCTS. 



623 



the appropriate factor (163) to obtain the percentage of commercial 
glucose. 

While theoretically pure molasses and syrups would be expected to 
show no rotation when polarized at 87° C. after inversion, as a matter 
of fact most samples exhibit a decidedly right-handed reading at that 
temperature. Occasionally a zero reading is noted, and in rare instances 
a slight left-handed rotation occurs under the above conditions. 

Dextro-rotation is undoubtedly caused by some form of decomposition 
or fermentation. It may be due to a preponderance of dextrose in the 
reducing sugars, since lexnilose is more easily decomposed than dextrose, 
or it may be caused by the decomposition products formed when the raw 
juice is being defecated with lime, or again it might result from a special 
fermentation forming dextran. 

The following table shows results by .\. H. Bryan* of polarization of 
samples of Louisiana molasses and syrup of known purity, showing 
especially the invert readings at 87° C: 

POLARIZATION OF LOUISIANA MOLASSES AND SYRUP. 



MOLASSES. 


SYRUP. 


Direct 
Polariza- 


Corrected Invert 
Polarization — 


Dry 

Substance. 


Direct 
Polariza- 
tion 
at 20° C. 


Corrected Invert 
Polarization — 


Dry 
Substance. 


at 20° C. 


At 20° C. 


At 87° C. 


At 20° C. 


At 87° C. 


° V. 
40.8 
24.6 
26.0 
42.4 
52.4 
55.6 


° V. 

— 20.24 

— 20.9 
-18.26 
-16.94 
-16.28 
-13-59 


° V. 

+ 2.2 
+ 2.2 
+ 3-52 
+ 2.42 
+ 2.20 
+ 4-18 


Per Cent. 
80.8 
76.8 
76.8 
78.2 
69.1 
69.6 
80.8 
79.0 
72.0 

73-8 
76.1 
74-0 
76.1 

78.1 

87-5 
84.1 
75-0 

78.0 


° V. 
48.4 
54-0 
50.2 
50.4 
61.8 


° V. 
-17.6 
-18.7 
— 12. 1 

-14.3 
-16-5 


° V. 
+ 1.98 

+ 3-30 
+ 6.i6t 
+ 1.76 
+ 2.20 


Per Cent. 

74.3 
68.3 


39-6 
39-6 


— 18.04 -t-2.20 

— 17.82 +2.20 

— 17.16 +2.64 

— 17.60 +2.42 


.\verage . 
Maximui 
Minim ur 




+ 2.65 

+ 6.16 

0.00 




44.0 
42.0 


n 




42.4 
41.6 

52.4 
26.6 
50.8 
22.6 
41.6 
45-6 


-17.27 
-16.94 

— 1 7 . 60 
-19.8 
-25.08 

— 16.72 
-14.74 
-15-4 


+ 3-52 
+ 3-96 
+ 3-52 
0.00 
+ 1.10 
+ 3.96 
+ 1.10 
+ 2.20 









* A. O. A. C. Proc, 1908, U. S. Dept. of -\gric., Bur. of Chem., Bui. 122, p. 182. 
f Sample ropy and badly fermented. 



624 



FOOD INSPECTION AND ANALYSIS. 



TYPICAL ANALYSES OF MOLASSES AND SYRUPS ADULTERATED WITH 

COMMERCIAL GLUCOSE. 



(a) Molasses 

{b) " 

(c) " 

(a) Golden drip syrup 

(b) " " 

(c) " " 

(a) Maple syrup 

(/;) " '* 

(0 " " 



Polarization. 



62 

98 

109 

73 
109 

143 
76 

77 
87 



+ 36-3 
+ 71.9 
+ 90 
+ 39-8 
+ 87.6 
+ 136 
+ 7-6 
+ 24 
+ 30.6 



S3 



18° 
17° 
18° 

17° 

18.4° 

18.6° 

22.4° 






19 
19.9 

14-5 

25 

16.9 

5-6 
51 
40.1 

42.5 



'2 S'oj 



oi^ 



30-03 

27.62 

33 • 1 1 
31 .61 

33-44 
38.17 
10.55 



16.90 



•3 X 

b o nl p 



24.6 

45 -o 

54.4 
27-7 
52.8 

78-s 

14.4 

21 .6 

25-4 



29.36 

27.98 

22.02 

23.67 

24.48 

21 .52 
31.91 
23-44 
28.80 



3-83 

3-53 
2.67 

3-94 
2.51 
1. 00 
0.65 

1.08 



Determination of Dextrin. — According to Bcckman's method a 
weighed amount of the honey or molasses is diluted with an equal volume 
of water and from ten to twelve times its volume of methyl alcohol is 
added. The precipitated dextrin is collected in a tared filter and thor- 
oughly washed with methyl alcohol, after which it is dried and weighed. 

Reduction of Saccharine Products to an Ash for Mineral Analysis. 
— If a considerable quantity of molasses, syrup, or other saccharine sub- 
stance is to be burnt to an ash, it is both tedious and annoying to ignite 
directly, by reason of the excessive swelling and frothing of such substances 
during ignition. Small quantities of molasses, syrup, or honey may with 
care be reduced to an ash by the method described on page 586. 

If a readily controlled electric current is available, it may be utilized 
as follows:* Mix 100 grams of molasses, syrup, or other saccharine 
solution, which should be evaporated to syrupy consistency if not already 
such, with about 35 grams of concentrated sulphuric acid in a large 
porcelain evaporating-dish. An electric current is then passed through 
it while stirring, by placing one platinum electrode in the bottom of the 
dish near one side and attaching the other to the lower end of the glass 
rod, with which the contents are stirred. Begin with a current of about 
I ampere and gradually increase to 4.! In from ten to fifteen minutes 

* Leach, 32d An. Rept. Mass. State Board of Health (1900), p. 653. Reprint, p. 37. 
This method is preferred to the ordinary method of heating with sulphuric arid, especially 
in case of molasses, because, if properly manipulated, it so quietly comes into the form of a 
very finely divided char or powder, especially adapted for subsequent quick ignition. 

t Modified from method of Budde and Schou for determining nitrogen electrolytically, 
Ztschr. anal. Chem., 38 (1899), p. 345. 



SUGAR AND SACCHARINE PRODUCTS. 625 

the mass is reduced to a fine, dry char, which may then be readily burnt 
to a white ash in the original dish over a free flame or in a muffle. 

Or, 100 grams of the molasses or syrupy solution to be ashed may 
be first evaporated to dryness and afterward mixed with from 10 to 20 cc. 
of concentrated sulphuric acid in a porcelain evaporating-dish, or if the 
substance to be ashed be a dry sugar or confectionery, 20 grams are 
mixed with the above amount of acid. Heat is gently applied by means 
of the gas flame till the swelling and frothing have ceased, which usually 
requires only a few minutes. The final ignition is then accomplished 
in the usual manner, nitric acid being added if necessary to completely 
destroy the organic matter. 

Determination of Tin in Molasses. — Fuse the ash from a weighed 
portion of the sample with sodium hydroxide in a silver crucible, dis- 
solve in water, and acidulate with hydrochloric acid; filter and precipi- 
tate the tin from this solution with hydrogen sulphide; wash the pre- 
cipitate on a filter and dissolve it in an excess of ammonium sulphide. 
Filter this solution into a tared platinum dish, and deposit the tin directly 
in the dish by electrolysis, using a current of 0.05 ampere and the appa- 
ratus described on page 608. 

Distinction between Invert Sugar, Maltose, and Lactose.* — All these 
sugars reduce Fchling's solution. Dextrose and levulose (invert sugar) 
when boiled with Barfoed's copper acetate solution (14 grams crystal- 
lized co[)pcr acetate and 5 cc. acetic acid in 200 cc. water) will form 
a precipitate of cuprous oxide, while neither maltose nor lactose will 
do this. The solution, which has thus been tested for invert sugar and 
found to be free, or the filtrate from the cuprous oxide precipitate, is 
treated with an excess of basic lead acetate, filtered, and to the filtrate 
is added an excess of sodium sulphate solution to precipitate the lead. 
The solution is again filtered and treated with copper sulphate solution, 
if not already blue. It is then made alkaline with sodium hydroxide 
and heated to boiling. A red precipitate of cuprous oxide at this stage 
indicates cither lactose or maltose or both. 

A solution of the sugar, made strongly ammoniacal, is then mixed 
with alkaline bismuth solution f and the container is set in a water- 
bath at 60° C. Maltose soon reduces the bismuth, but lactose does not. 

To test for lactose, arid strong nitric acid to the solid sugar residue 

* Bartley and Mayer, Merck's Report, 12 (1903), p. 100. 

t This reagent is prepared as follows: Bismuth subnitrate, 2 grams; Rochelle salt, 4 
grams; sodium hydroxide, 8 grams; dissolved in 100 cc. of water by the aid of heat. 



626 FOOD INSPECTION AND ANALYSIS. 

and warm gently till red fumes come off. Then set the container in hot 
water and cool gradually. Crystals of mucic acid appear after a time 
if any appreciable amount of lactose be present. 

Determination of Lactose or Maltose. — Either sugar, if in solution 
free from other reducing sugars, may be determined by the volumetric 
Fehling method (p. 591) or by the Defren method, using the table on 

page 595- 

For the determination of maltose in commercial glucose, see page 630. 

Estimation of Cane Sugar and Dextrose in Mixtures. — Obtain true 
direct and invert readings of a normal solution of the mixture. Deter- 
mine the per cent of sucrose by Clerget's formula (p. 588). This figure 
represents the right-handed rotation due to sucrose. Subtracting this 
from the direct polarization, the difference represents the right-handed 
rotation due to dextrose. The specific rotary power of sucrose is 66.5 
and that of dextrose 52.3. 

Calling d the percentage of dextrose and R' the right-handed rota- 
tion due to dextrose as above obtained, if the Soleil-Ventzke scale is used, 

66.5:52.3 = J:i?S 
whence 

52-3 

Determination of Levulose.* — On page 589 attention was called to 
the variation in the rotary power of levalose with the temperature. This 
variation is constant, and i gram of levulose in 100 cc. of water produces 
a decrease in left-handed reading of 0.0357° on the cane sugar (Ventzke) 
scale for each 1° C. increase in temperature. Therefore, the weight 
of levulose present in a given solution can be calculated from the polari- 
scopic readings at two temperatures, using a water-jacketed tube, as 
described on page 639. 

R-R' 



L = 



0.0357 {t-t')* 



where Z, = weight of levulose, 

2? = reading at higher temperature tj 
R' = reading at lower temperature t'. 

The percentage of levulose present in the solution may readily be cal- 
culated as follows: 

* Wiley, Agric. Anal., p. 272. 



SUGAR AND SACCHARINE PRODUCTS. 627 

If L'= percentage of levulose, 

L = weight of levulose in solution, 
IF = weight of sugar sample made up to 100 cc, 
_LXioo 

In a normal solution 1^" = 26.048. 

ANALYSIS OF MAPLE PRODUCTS. 

Determination of Moisture. — This is accomplished by direct drying 
with sand, or by calculation from the specific gravity, or, preferably from 
the refractive index. See molasses methods, page 613. 

Determination of Ash. — Burn 5 grams in a platinum dish by the usual 
method, observing the precautions given for molasses, page 614. 

Soluble and Insoluble Ash* — To the platinum dish containing the 
ash add 40 cc. of hot water and boil gently for two minutes. Filter through 
a small ashless filter, and wash with hot water until the filtrate amounts 
to 100 cc. Return the filter to the dish used for ashing, burn at a low 
red heat, cool and weigh, thus obtaining the insoluble ash. The soluble 
ash is obtained by difference, subtracting the weight of insoluble from 
that of total ash. 

Alkalinity of Soluble Ash.\ — Allow the filtrate from the above deter- 
mination to cool, then titrate with tenth-normal hydrochloric acid, using 
methyl orange as an indicator. 

Alkalinity of Insoluble Ash.-\ — Add excess of tenth-normal hydrochloric 
acid (usually 10 to 15 cc.) to the ignited insoluble ash in the platinum 
dish, heat to the point of boiling over an asbestos plate, allow to cool, 
and titrate excess of hydrochloric acid with tenth-normal sodium hydroxide, 
using methyl orange as an indicator. 

Express the alkalinity in each case as the number of cubic centimeters 
of tenth-normal acid used on the ash of i gram of sample. 

Polarization. — See page 614. 

Determination of Reducing Sugar. — See page 621. 

Determination of Malic Acid Value. — Modified Leach and Lythgoe 
Method.\ — Weigh 6.7 grams of the sample into a 200 cc. beaker, and add 

* A. H. Bryan, U. S. Dept. of Agric, Bur. of Chem., Circ. No. 40, p. 6. 
t U. S. Dept. of Agric , Bur. of Chem., Bui. 107 (rev.), p. 69. 

X Jour. Am. Chem. Soc, 26, 1904, pp. 380 and 1536; U. S. Dept. of Agric, Bur. of 
Chem., Bui. 107 (rev.), p. 74. 



628 FOOD INSPECTION ^ND ANALYSIS. 

water to make a volume of 20 cc. Add 2 drops of ammonium hydroxide 
(specific gravity, 0.90), i cc. of a 10% solution of calcium chloride, and 
60 cc. of 95% alcohol. Cover the beaker with a watch glass, heat for 
one-half hour on a water bath, then turn off the flame and allow the 
beaker to stand overnight. Filter the material in the beaker through 
good quahty filter paper, wash the precipitate with hot 75% alcohol until 
the filtrate measures 100 cc, dry and ignite. Add from 15 to 20 cc. of 
tenth-normal hydrochloric acid to the ignited residue, thoroughly dissolve 
the hme by heating carefully to just below boiling, cool and titrate the 
excess of acid with tenth-normal sodium hydroxide, using methyl orange 
as an indicator. One-tenth of the number of cubic centimeters of acid 
neutralized by the ignited residue expresses the malic acid value. Run 
blank determinations on reagents, using the same amounts, particularly of 
ammonium hydroxide, as were used in the original determination, and 
make the necessary correction. 

Determination of Lead Number. — Winton Method.'^ — Weigh 25 
grams of the material (or 26.048 grams if it is desired to determine sugars 
polariscopically in the same portion) and transfer by means of water 
into a loo-cc. flask. Add 25 cc. of standard lead subacetate solution, 
fill to the mark, shake, allow to stand at least three hours and filter through 
a dry filter. From the clear filtrate pipette off 10 cc, dilute to 50 cc, 
add a moderate excess of sulphuric acid, and 100 cc of 95% alcohol. 
Let stand over night, filter on a Gooch crucible, wash with 95% alcohol, 
dry at a moderate heat, ignite at low redness for three minutes, taking 
care to avoid the reducing cone of the flame, cool, and weigh. Calcu- 
late the amount of lead in the precipitate, using the factor 0.6829, subtract 
this from the amount of lead in 2.5 cc. of the standard solution, multiply 
the remainder by 100, and divide by 2.5, thus obtaining the lead. number. 

The standard lead subacetate is prepared by diluting one part of 
the ordinary solution (page 586) with four volumes of water, filtering if 
not clear. It is standardized by determining the lead in 25 cc as above 
described. The solution deposits a slight precipitate on standing, but 
this does not usually appreciably affect its strength. 

Determination of Hortvet Number.f — The method depends on the 
principle that the volume of the precipitate, by treatment of the sugar 
solution or syrup under fixed conditions with alumina cream and sub- 
acetate of lead, varies with the amount of refined sugar present. 

* Jour. Am. Chem. Soc, 28, 1906, p. 1204. 
t Ibid., 26, 1904, p. 1532. 



SUGAR AND SACCHARINE PRODUCTS. 



629 



Apparatus. — (i) A tube, adapted to be carried in the shield of the 
centrifuge. This tube, which is 15.3 cm. in length, has a wide cylindrical 
portion 3 cm. in diameter, narrowed at the top to a neck 2 cm. in diameter, 
and at the bottom to a stem graduated in tenths to 5 cc. 

(2) A holder, made of pine or white wood, of a size adapted to carry 
the tube in the shield of the centrifuge. The holders and tubes should 
be arranged in balanced pairs in the centrifuge. 

Procedure. — Introduce 5 cc. of syrup or 5 grams of sugar into the 
tube. Add 10 cc. of water, and dissolve completely. Next add 10 drops 
of alumina cream, and i .5 cc. of lead subacetate . Shake thoroughly, 
and allow to stand from forty-five to sixty minutes. Place the tube in 
its holder in the centrifuge shield, and run six minutes. If, after the 
end of this time, any material adheres to the sides of the wide part of the 
tube, loosen with a small wire or by giving the tube a slight twist, then 
run the tube six additional minutes, and finally read the volume of the 
precipitate in the stem, estimating to o.oi cc. 

Run a blank with the above reagents in water, subtracting the blank 
reading from that of the precipitate. In the case of syrup, reduce to 
the 5 -gram basis by dividing by the specific gravity of the sample. If 
the sugar content of the sample is known, the specific gravity can be 
calculated from the table on page 617. For pure maple syrup 1.33 is 
very nearly correct. 

The following table shows results obtained by Hortvet on two samples 
of maple syrup of known purity, mixed with varying amounts of refined 
cane sugar syrup of the same density: 







Com- 






Com- 






Com- 




Purity. 


Five 


puted 


Differ- 


Ten 


puted 


Differ- 


Twelve 


puted 
Precipi- 


Differ- 


Minutes. 


Precipi- 


ence. 


Minutes. 


Precipi- 


ence. 


Minutes. 


ence. 






tate. 






tate. 






tate. 




Per Cent. 


cc. 


cc. 


cc. 


cc. 


cc. 


cc. 


cc. 


cc. 


cc. 


100 


4.90 






3-29 






2.80 






25 


1 .00 


1.22 


0.22 


0.70 


0.82 


0.12 


0.65 


0. 70 


0.05 


50 


3.60 


2-45 


I-I5 


1.50 


1-54 


0. 14 


1.40 


1.40 


0.00 


75 


4.60 


3-67 


0-93 


2.77 


2.47 


0.30 


1.90 


2. 10 


0.20 


100 


5-40 






4.40 






3-75 






10 


0.30 


0-54 


0.24 


0.28 


0.44 


0.16 


0.28 


0-37 


0.09 


20 


1.27 


1.08 


0. 19 


0.80 


0.88 


0.70 


0.70 


0-75 


0.05 


60 


5.00 


3-24 


1.76 


2.70 


2.64 


0.06 


1.70 


2.25 


0-5S 



The blank at the end of twelve minutes was 0.44 cc. The machine 
used for the above experiment had a radius of 18.5 cm., and a speed of 
1600 revolutions per minute. Results obtained by Hortvet on known 



630 FOOD INSPECTION AND ANALYSIS. 

pure maple syrups vary from 1.2 cc. to about 2.5 cc, and on known 
pure maple sugars from i .8 cc. to 4 cc. 

Commercial brands of adulterated syrups and sugars give such pre- 
cipitates as 0.00 cc, 0.02 cc, 0.05 cc, and 0.08 cc Hortvet regards with 
suspicion a syrup testing lower than 1.2 cc, and when the result is below 
I cc, the sample is positively condemned as being mixed with refined 
cane sugar. In the case of sugar, a somewhat higher minimum figure 
is adopted than with syrup. In view of the fact that the speed has much 
to do with the volume of the precipitate, the analyst should make a series 
of similar experiments with his own centrifuge, and work out his own 
standards. Results may be better compared with each other, if calculated 
on the water-free basis. 

In case of doubt, and in fact in ;<ll cases at first, it would be well 
to make confirmatory tests, such as determining the ash and reducing 
sugar. 

Sy's Lead Method.* — In a 25-cc. graduated cylinder introduce 5 cc. 
of syrup, or 5 grams of sugar which is afterwards dissolved in a little 
water. Add water to the 15 cc mark and 2 cc of lead subacetate solution. 
Shake thoroughly and allow the mixture to stand twenty hours. Then 
read the volume of the precipitate, which for pure maple products should 
be at least 3 cc and is usually over 5 cc. 

ANALYSIS OF COMMERCIAL GLUCOSE, 

Wileyt has worked out a method for calculating the percentage of 

dextrin, maltose, and dextrose present in commercial glucose, based 

on the specific rotary power of these substances and on the reducing 

power of maltose and dextrose. To aj)ply this method, the operator, 

if he has a polariscope reading in sugar scale degrees, must ascertain 

the equivalent readings in angular degree? from the table on page 583, 

and calculate the specific rotary power in each case from the formula 

, . looa 

Wd = -^. page 584- 

Thus, if he possesses a Schmidt and Haensch instrument, he should 
multiply the true reading, as obtained on that instrument, with a normal 

* Jour. Am. Chem. Soc, 30, 1908, p. 1430. 

t Chem. News, 46, p. 175; Agric. Anal., 3, pp. 288-290. 



SUGAR AND SACCHARINE PRODUCTS. 631 

solution of the given sugar or mixture, by the factor 0.3468, to convert 
the reading into circular degrees from which to figure the specific rotar}'- 
power as above. 

The specific rotary power of dextrin is fixed at 193, that of maltose 
138, and that of dextrose at 53. 

Then if P = total polarization of the mixture in terms of specific 
rotary power, J = per cent dextrose, w=per cent maltose, and J'=per 
cent dextrin, 

^ = 53^+138^+193^' (i) 

The value of P is obtained from observation and calculation as above 
described on a known solution of the sample, say 10 grams in 100 cc. 
The reducing sugars, maltose and dextrose, are then removed, prefer- 
ably by oxidation with cyanide of mercury, as follows:* 

Prepare the reagent by dissolving 120 grams mercuric cyanide and 
120 grams sodium hydroxide in water, mixing the two solutions, and 
making up to 1,000 cc. Remove any precipitate that may gather by 
filtration. 

Make a solution of 10 grams of the glucose sample in 100 cc. and 
take 10 cc. of this solution in a 50-cc. graduated flask. Add sufficient 
mercuric cyanide solution to have an excess of reagent after the oxidation 
(from 20 to 25 cc), and boil for three minutes under a hood with a good 
draft. Cool and neutralize the alkali with concentrated hydrochloric 
acid, adding the latter till the brown color is discharged. By this method 
the optical activity of the maltose and dextrose is discharged, while that 
of the dextrin remains unaffected. From the polariscope reading cal- 
culate as above the specific rotary power of the dextrin {P'). Then 

P' = ^9?>d' (2) 

The reducing power on Fehling's solution of dextrose is to that of 
maltose as 100 is to 62. Whence, if i?= reducing sugar (reckoned as 
dextrose) we have 

R = d-\- 0.62m (3) 

Subtracting equation (2) from equation (i) we have 

P-P' = 53J+i38m (4) 

* Wiley, Agric. Analysis, p. 290. 



632 FOOD INSPECTION AND ANALYSIS 

Multiplying equation (3) by 53 and subtracting from equation (4), 

P-P' = 53(/+i38w, 
53 ^ = 53^+ 32-86W, 

■P--P'-53^ = io5.i4W (5) 

Therefore 

m = ■, (6) 

105.14 ' ^ ^ 

d = R— 0.62m, (7) 

pf 

d' = — (8) 

193 

Determination of Dextrin in Commercial Glucose. — One volume of 
the sample is well shaken with about 10 volumes of 90% alcohol, and 
the precipitated dextrin is separated by filtration through a tared filter, 
washed thoroughly with strong alcohol, dried at 100°, and weighed. 

Qualitative Tests for Commercial Glucose. — Several confirmatory 
chemical tests may be employed for commercial glucose, aside from 
the optical test with the polariscope. Thus a precipitate of dextrin 
by treatment of the sample with an excess of strong alcohol, in the absence 
of mineral salts insoluble in alcohol, is strongly indicative of commercial 
glucose. An excess of calcium sulphate in the ash also points strongly to 
the presence of glucose. 

Arsenic in Commercial Glucose. — Like all products wherein commer- 
cial sulphuric acid is employed in its manufacture, glucose sometimes 
contains arsenic, though usually in minute traces. Arsenic is readily 
indicated, when present, by the Gutzeit test, conducted as follows: 2 
grams of the sample are introduced into a small Erlenmeyer flask of about 
100 cc. capacity, and diluted with 5 to 10 cc. of water. Scraps of arsenic- 
free, granulated zinc are then added. A small filter-paper is carefully 
folded smoothly around the bottom of a cork that loosely fits the mouth 
of the flask, and is moistened with a concentrated solution of mercuric 
chloride. From 6 to 8 cc. of arsenic-free concentrated hydrochloric * 
or sulphuric acid are then added to the flask, so as to produce rapid, but 
not too violent evolution of gas, and the cork is loosely inserted. 

After ten minutes the cork is removed, and, if a yellow stain is present 
on the filter, arsenic is indicated. The amount of arsenic present varies 

* Hydrochloric acid is better than sulphuric acid, as the action is much more brisk with 
pure zinc. 



SUGAR AND SACCHA'^INE PRODUCTS. 633 

with the depth of color, and if a large amount is present the stain may 
be dark brown or even black. 

Sulphides interfere with the Gutzeit test, but are rarely present in 
commercial glucose. Unless sure of the purity of the reagents it is well 
to make a blank test thereon. In such a blank, the filter should be per- 
fectly white after ten minutes. 

The amount of arsenic may be roughly determined colorimetrically 
by the Gutzeit method. 

For more careful determination, employ the Marsh apparatus, into 
which the diluted glucose may be directly introduced without previous 
treatment. 

HONEY. 

Composition and Occurrence. — Honey is the saccharine product 
deposited by bees {Apis mellifica and A. dorsata) in the cells of honey 
comb, which the insect forms out of wax secreted by its body. Honey 
has its source chiefly in the nectaries of flowers, from which the bees 
abstract it, also in the juices of ripe fruits and the exudations of leaves 
(honeydew). While in the honey-sac of the bee, the sucrose, which 
forms the chief constituent of the fruit juice or nectar, becomes for the 
most part inverted, forming, in the honey, dextrose and levulose. The 
evaporation to a syrupy consistency is effected in the hive by exposure 
to a current of air, produced by fanning of the wings of the bees. 

The flavor of honey varies considerably, according to its source. 
Besides water, the sugars, and mineral matters, pollen is usually present, 
derived from the flowers, also as a rule a small quantity of wax, and 
nearly always appreciable amounts of various organic acids, such as 
formic. 

European Honey. — Neufeld* gives the following limits for pure 
honey : 

Water 8.30 to 33.59% 

Protein 0.03" 2.67% 

Invert sugar 49-59 " 93-9^% 

Sucrose o.io " 10.12% 

Dextrin o-99 " 9-7°% 

Formic acid 0-03 " 0.21% 

Ash 0.02 " 0.68% 

* Der Nahrungsmittelchemiker als Sachverstandiger., Berlin, 1907, p. 275. 



634 FOOD INSPECTION AND ANALYSIS. 

Canadian Honey. — A large number of samples of genuine honey 
analyzed in 1897 for the Department of Inland Revenue, Canada (Bui. 
47), showed the following variations: 

Direct polarization — 2.4 to — 19 

Invert " -10.2 " -28 

Sucrose (by Clerget) 0.5 " 7-64% 

Invert sugar 60.37 " 78.8% 

Water 12 '* 33% 

Ash 0.03 " 0.50% 

American Honey. — Browne* has examined 97 samples of American 
and Hawaiian honey, representing the product made from the nectar 
of numerous flowers as well as honeydew. Maxima and minima of 
polarizations and analyses of some of the more important kinds, and of 
all the levorotatory and the dextrorotatory samples are given in the table 
on page 635. 

As regards the chemical characteristics of honey from different flowers, 
Browne states that alfalfa honey usually has less dextrin and undetermined 
matter — the so-called ' impurities " — and more sucrose than the other 
varieties, although the low amount of impurities is, to some extent, char- 
acteristic of the honey of the whole family (leguminosae) . The compositas 
yield honey with about the average amount of organic non-sugars; the 
rosaceae yield a product low in dextrin, but high in undetermined m; tter. 
Buckwheat and other polygonaceous honeys contain almost no sucrose, 
but give tests for tannins. Basswood honey is relatively high in dextrin, 
and that from poplar, oak, hickory and other trees, all of which contain 
considerable quantities of honeydew, are rich in both dextrin and ash. 
Pronounced tannin reactions are obtained in honey gathered from the 
flowers or plants of the sumac, hop and others rich in tannin. Tupelo, 
mangrove and sage honeys are distinguished by their high levulose content. 

Browne found the average per cent of water in honey from the arid 
states of Arizona, Nevada, Utah, and Colorado was 15.60, and from the 
humid states of Minnesota, Wisconsin, Illinois, Missouri and Iowa was 
18.88, 

Hawaiian Honey. — This is characterized by its high ash and the 
presence of decided amounts of chlorides in the ash. Van Dinef states 

* U. S. Dep'i. of Agric, Bur. of Chem., Bui. no (1908). 
flbid., p. 52. 



SUG/tR AND SACCHARINE PRODUCTS. 



635 













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636 



FOOD INSPECTION /IND yINA LYSIS. 



that the floral honey of Hawaii is largely from the blossoms of the algarroba 
{Prosopis juliferd), while the honeydew honey, which, together with 
mixtures of honeydew and floral honey forms about two-thirds of the 
product of the Hawaiian Islands, comes largely from the exudations of 
the sugar-cane leaf-ho])per {Perkinsiella saccharicida) , and the sugar- 
cane aphis {Aphis sacchari). Honeydew honey is dextrorotatory, and 
for this reason has often been condemned as adulterated. It has a strong 
molasses-like odor, and often a very dark color. Bakers prefer it to 
algarroba honey, because of its baking and boiling properties. 

The variation in the composition of Hawaiian honey is shown in the 
table on page 635, compiled from Browne's data. 

Dextrorotarory Honey. — The U. S. standards define honey as levo- 
rotatory, thus excluding the larger part of the Hawaiian product, and also 
unimportant kinds of honey made from certain trees. Pure floral honey 
with no admixture of honeydew is seldom if ever dextrorotatory. 

The following are the results obtained by Browne in the examination 
of detrorotatory honeys: 



SI 



Hawaiian. 



I' e ^• 

V- n S & 



•a s; 






Direct polarization at 20° C.*.. . 
Invert polarization at 20° C. . . . 
Invert polarization at 87° C. . . . 

Water per cent 

Invert sugar 

Sucrose 

Ash 

Dextrin 

Undertermined 

Free acid as formic .... 

Reducing sugar as dextrose 

per cent 



+ 17.0 
+ 15.0 

+ 35-0 

16.44 

71.69 

0.61 

0.29 

6.02 

4-95 
0.05 

68.68 



+ 3- 

— 2. 

+ 20. 

17- 

65- 



3.10 

0.76 

10.19 

0.19 
63 • 04 



+ 7-8 
+ 3-4 
+ 26.6 
16.0=; 
65.89 
2.76 
0.78 
12.95 
1-57 



63.12 



-h II .0 
+ 5-2 

-1-28.6 

13-56 
65.87 

4-31 

0.79 

10.49 

4.98 

0.08 
63.11 



+ 17.8 

+ 13-5 
+34.8 
15-46 
64.84 

5-27 

1.29 
10.01 

0.15 
62.12 



+ 3.6 
+ 1.9 
+ 23.7 
16.29 
67.81 

2-57 
1.02 

9-65 
2.66 
0.14 

64.96 



+ 5-3 
+ 1.9 

+ 23.4 
17.80 
66.85 
2.41 
0.80 
8.62 
3-52 
0.13 

64.04 



* Constant. 



Adulteration of Honey. — The most common adulterants of honey 
are cane sugar, commercial invert sugar, and commercial glucose. Some- 
times two or more adulterants are employed in the same sample. Gelatin 
is also said to be used. It appears to be a fact that bees may be made 
to feed upon cane syrup or commercial glucose, if these materials are 
placed in proximity to their hives, so that in some instances the adulterant 



SUGAR AND SACCHARINE PRODUCTS. 637 

may be supplied through the medium of the bee. Sophisticated honey 
IS often put up in tumblers or jars containing pieces of honeycomb, so 
that presence of the comb is by no means proof of its purity. Comb-honey, 
sold in the frame as sealed by the bees, is never adulterated, except when 
the bees are fed upon glucose or cane sugar. 

Cane Sugar. — The following are typical analyses of honey adulterated 
with cane sugar: 

A. B. C. 

Direct polarization. .. . +34.7 +12 + 1.2 

Invert " .... —24 —17.6 —21.5 

Temperature 14° 15° i9-5° 

Sucrose (Clerget) 43-i6% 21.8% 17.07% 

Invert sugar 42.48% 60.03% 67.2%, 

Water 42.42%) 21.15% 15 06% 

Ash .11% 0.06% 

A strong right-handed polarization before inversion, coupled with a 
left-handed invert reading at 20°, is evidence of adulteration with cane 
sugar, or a product containing cane sugar. 

Honey stored by bees fed on cane sugar is also characterized by its 
right-handed polarization. Although the bee inverts the larger part of 
the cane sugar in its body, this inversion is never as complete as in the 
case of nectar honey. 

Glucose. — The following are typical analyses of honey adulterated 
with commercial glucose: 

A.* B. C. 

Direct polarization. . -I-147 4-66.9 -f-ioi.5 

Invert " .. 4-135.2 4-61.9 4- 99.0 

Temperature 18° 20° 22° 

Sucrose (Clerget).... 8.83% 3.76% 0.0% 

Invert sugar 46.18% 74.66% 49.87% 

Water i5-i9% 21.40%,! 23.7% 

Ash 0.03% 

Care should be taken not to confuse honeydew honey with honey 
adulterated with glucose. Browne gives the following means of distinction : 
(i) the diftprence in invert polarization between 20 and 87°, corrected to 
77% invert sugar, (2) Beckman's iodine test (page 641), and (j) the 

* Both commercial glucose and added cane sugar. 



63S 



FOOD INSPECTION AND ANALYSIS. 



Konig and Karsch test (page 642). He also finds the quantity and 
character of the ash, the acidity, and microscopic examination of value. 

The following analyses of mixtures of commercial glucose and honey 
were made by A, H. Bryan.* 



Mixture. 


Constant 


Invert Polarization — 


Polariza- 


Invert 


Sugar 


Calculated Glucose. 




















100 — 






Direct 








tion 






I t 


Invert 


(Correct- 






Polariza- 








Differ- 




After 




Polariza- 


ed Polar- 


Glucose 


Honey. 


tion at 
20° c. 


At 


20° c. 


At 87°C. 


ence 
(87°- 
20°). 


Inver- 
sion. 


Inver- 
sion. 


tion at 
87°- 
1.63. 


(2o°C.-l- 

17.5)^ 

I-93- 


ization 
Differ- 
ence X 
100-^ 
26.7) 


% 


% 


°v. 




°v. 


° V. 


°V. 


% 


% 


% 


% 


% 


100 




+ IS3-8 


+ 


153-34 


+ 144-32 




30.02 


30.45 


88.5 


88.5 




50 


50 


+ 67.0 


+ 


65.67 


+ 73-81 


8.14 


53-67 


54.5c 


45-3 


43-1 


56-9 


20 


80 


+ 15-4 


+ 


13-42 


+ 33-00 


19.58 


69.00 


70-35 


20.2 


16.0 


19.2 


10 


90 


- 2.4 


— 


4.84 


+ 18.59 


23-43 


74.42 


74-1- 


II. 4 


6.6 


8.8 


5 


95 


- 11-5 


— 


14-31 


+ 11.66 


25.96 


75-74 


77.8c 


7-2 


1.6 


3-8 


3 


97 


- 14.2 


— 


16.94 


+ 9-13 


26.07 


76.62 


78.01 


5-6 


0.29 


3-7 


2 


98 


— 16.0 


— 


18.70 


+ 8.14 


26.84 


76.64 


78.34 


5-0 


0.00 


1.2 


I 


99 


- 18.2 


— 


20.90 


+ 6.93 


27-83 


77.2c 


78.87 


4-2 


0.00 


0.0 




100 


- 19-5 




22.11 


+ 5-94 


28.05 


77. 6t 


78-9, 


3-2 


0.00 


0.0 



Commercial Invert Sugar is the most difficult of detection of all the 
adulterants. Herzfeld's processf for the manufacture of invert sugar 
syrups consists in boiling for thirty to forty-five minutes i kilogram of 
refined sugar in 300 cc. of water with i.i gram of tartaric acid. Brownf 
gives the following analysis of the product made by this process: 

Direct polarization at 20° — 6.2 

Constant polarization at 20° — 9.5 

Invert polarization at 20° — 16.9 

Invert polarization at 87° -f 4.8 

Water 16.32% 

Invert sugar 73-38% 

Sucrose 4.36% 

Ash o.oc%o 

Dextrin 4.86% 

100.00 
Acids as formic 0.06% 

*A. O. A. C. Proc, 1908, U. S. Dept. of Agric, Bur. of Chem., Bull. 122, p. 181. 
t Zeits. ver. d. Zucker-Ind., 31, p. 1988. 
X loc. cit., page 64. 



SUG/IR AND SACCHARINE PRODUCTS. 639 

This adulterant is best detected by Browne's test (page 642). Ley's 
test* has value in confirming the results of Browne's test, but should be 
used with caution, as American honeys do not react like the European. 

Gelatin is indicated if a precipitate occurs in the diluted sample with 
a solution of tannic acid. 

ANALYSIS OF HONEY. 

Preparation of Sample. — In the case of strained honey, stir with a rod 
till any separated sugars are evenly distributed throughout the mass, or, 
if the honey has become solidified wholly or in part bv crystallization, use 
a gentle heat on a closed water-bath to restore it to fluid form. 

In the case of comb honey, cut with a knife across the top of the comb 
if sealed, and separate completely from the comb by straining through 
a 40-mesh sieve. 

Determination of Moisture.f — Weigh 2 grams into a flat-bottom 
metal dish 2| inches in diameter, which, together with 10 to 15 grams 
of fine quartz sand and a short stirring rod, has been previously tared, 
add 5 to 10 cc. of water, stir until the whole has been thoroughly incor- 
porated, and dry to constant weight at 65 to 70° C. in a vacuum oven. 
Honeys of high purity usually dry in twelve hours, while those of the 
honeydew class rich in dextrin and gum require thirty-six hours, or longer. 

Determination of Ash. — See page 614. 

Polarization. — Direct and Invert at 20° C. — Proceed as directed under 
molasses (page 614), except that only alumina cream is used as a clarifier. 
To destroy birotation add a drop or two of ammonia before making up 
to the mark 4 

Invert at 87° C. — Invert a half normal portion in the usual manner in 
a loo-cc. flask, cool, add a few drops of phenolphthalein and enough 
sodium hydroxide to neutralize; discharge the pink color with a few drops 
of dilute hydrochloric acid, add from 5 to 10 cc. of alumina cream, 
make up to the mark and filter. Polarize in a 200-mm. tube at 87°, and 
multiply reading by 2. 

Polarization at the temperature of 87° can most readily be effected 
by the use of a water-jacketed tube, as shown in Fig. in. An all-metal 
tube, the interior of which is heavily gold-plated to avoid corrosion by 
acid, is preferable to one in which the inner tube is glass with a metal 

* Pharm. Zeits., 47, 1902, p. 603. 

t Browne, U. S. Dept. of Agric, Bur. of Chem., Bui. no, p. 18. 

X Friihling, Zeits. offentl. Chemie, 4, 1898, p. 410. 



640 FOOD INSPECTION AND AN/tLYSIS. 

jacket, as in the latter leaky joints are liable to occur, due to uneven 
expansion. A tubulure is provided in the outer tube for a thermometer, 
so that the exact temperature may be noted. A tank of boiling water 
placed on a shelf above the polariscope is connected by rubber tubing 
with the jacketed tube as it rests in the polariscope, as shown in Fig. iii. 

Determination of Reducing Sugars.— Determine by Allihn's method 
(page 608) in an aliquot of 25 cc. of a solution obtained by making 10 cc. 
of the solution prepared for polarization up to 250 cc. If desired the 
sugar may be determined by the volumetric Fehling process (page 591). 

The reducing sugars may be calculated as dextrose as obtained from 
Allihn's table, or as levelose by multiplying the dextrose by 1.044. 

Determination of Levulose. — Wiley's Method.'^ — This may be calcu- 
lated approximately by the following formula: 

100(1.0315/1—0) 100(1.0315^1 —a) 
(2.3919)26 62.19 

in which Z=levulose, a = the direct polarization at 20° of a solution of the 
normal quantity of honey made up to 100 cc. at 20°, and ^ =the direct 
polarization of the same solution at 87° C, 2.3919 = the variation in 
polarization of i gram of levulose in 100 cc. of solution between 20 and 
87° C, and i.o3i5=the factor for converting the volume of the solution 
at 20° into that at 87° C. 

Determination of Dextrose.!— Mukiply the percentage of levulose 
as obtained in the proceeding section by 0.91 5, thus obtaining the equivalent 
dextrose, and subtract this from the per cent of reducing sugars expressed 
as dextrose. 

Determination of Sucrose. — Owing to the inaccuracies of Clerget's 
method as appHed to honey, Browne recommends the following : Neutralize 
the free acid of 10 cc. of the solution used for invert polarization with 
sodium carbonate, make up to 250 cc. and determine the reducing 
sugars by Allihn's method. Subtract from the invert sugar thus obtained 
the invert sugar found before inversion, and multiply the difference by 
0.95. 

Determination of Dextrin. — Brotvne's Method.-\ — Weigh 8 grams of 
honey directly into a loo-cc. flask, add 4 cc. of water, and finally with 

* Principles and Practice of Agricultural Analysis, 1897, III, p. 267. Browne, loc. cit., 
p. 17. 

I Browne, loc. cit., p. 17. Jour. Am. Chem. Soc, 28, 1906, p. 446. 



SUGAR AND SACCHARINE PRODUCTS. 641 

continual agitation sufficient absolute alcohol to fill to the mark. Shake 
thoroughly and allow to stand twenty-four hours, or until the dextrin is 
deposited on the bottom and sides of the flask and the liquid is perfectly 
clear. Decant on a filter and wash the precipitate in the flask with 10 cc. 
of cold 95% alcohol, pouring the liquid finally on the filter. Dissolve 
the precipitate in the flask and on the filter in a little boiling, distilled 
water, collecting the solution in a tared platinum dish. Evaporate the 
hquid, and dry to constant weight at 100° C. If the alcohol precipitate 
is considerable, it should be dried at 70° C. in vacuo. After weighing, 
dissolve in water and make up to a definite volume according to the 
weight as follows: 

Residue, grams. 0-0.5 0.5-1.0 i. 0-1.5 i- 5-2.0 2.0-2.5 2.5-3.C 
Volume, cc. . .. 50 100 150 200 250 300 

Filter, determine invert sugar and sucrose in aliquots by copper reduction 
before and after inversion, and subtract the sum of these sugars from the 
total alcohol precipitate. 

Determination of Acids. — Dissolve 10 grams of the honey in water 
and titrate with tenth-normal sodium hydroxide, using phenolphthalein 
as indicator. Express result as formic acid. 

Beckman's Test for Glucose.* — Treat a mixture of equal parts of 
honey and water with a solution of iodine in potassium iodide. If glucose 
is present, a red or violet color (due to erythro- or amylo-dextrin) appears, 
the shade and intensity depending on the nature and amount of the 
glucose present. 

Determination of Commercial Glucose in Honey. — Except for rough 
work, the method described on page 622 for calculating the per cent of com- 
mercial glucose from the sucrose and from the direct polarization is not 
recommended for use with honey and other products wherein the invert 
sugar is so large as to considerably affect its accuracy. In this case, it 
is best after inversion to polarize the sample at 87° C, the temperature at 
which the reading due to invert sugar would theoretically be o. At 
this temperature, any considerable right-handed polarization can be 
accounted as due to commercial glucose. (See page 639.) 

As in the case of molasses, the writer advocates assuming 175° as the 
direct polarization of the glucose used, this being about the maximum 
reading for a normal solution of 42°-Be. glucose. Lythgoe has shown 

* Zeits. Anal. Chem., 35, 1896, p. 267. 



642 FOOD INSPECTION ^ND ^Ny^ LYSIS. 

that in polarizing at high temperatures samples of saccharine products 
containing commercial glucose, certain precautions have to be observed 
not necessary when cane or invert sugar are the only sugars present. 
Thus, a normal solution of glucose, when polarized at 87° C, has a lower 
reading than in the cold, the difference being doubtless due partly at 
least to the expansion of the liquid. Again, on subjecting a normal 
solution of glucose to inversion with acid, as in Clerget's process, and 
heating to 87° C, it will be found impossible to get a constant reading, 
but the reading will drop rapidly, due to a partial hydrolysis of the maltose 
or dextrin. 

In honey and other j^reparations containing much invert sugar and 
commercial glucose, it is best to proceed as follows: Divide the polariza- 
tion at 87° by 163* and multiply the result by 100 for the percentage of 
commercial glucose in terms of glucose polarizing at 175°. It should be 
borne in mind that the results by even this method are only approximate, 
as genuine honey is more or less dextrorotatory at 87° C. 

The following formula is used by European chemists: G= m 

1-93 
which G=^the per cent of commercial glucose, and 6-= the polarization 
after inversion at 20'^ C. 

Browne's Test for Commercial Invert Sugar.f — Reagent. — This 
should be freshly prepared each time before using. Shake 5 cc. of c. p. 
anilin with 5 cc. of water, and add sufficient glacial acetic acid (2 cc.) to 
just clear the emulsion. 

Process. — Treat 5 cc. of a i : i solution of the honey in a test tube 
with I to 2 cc. of the anilin reagent, allowing the latter to flow down the 
walls of the tube so as to form a layer upon the honey solution. If, when 
the tube is gently agitated, a red ring forms beneath the anilin solution, 
this color becoming gradually imparted to the whole layer, artificial 
invert sugar is present. This reaction is due to furfural formed during 
the high temperature employed in the commercial processes of inversion. 
Boiling genuine honey also causes the formation of furfural, but this treat- 
ment impairs the flavor and is probably never practiced. 

Distinction of Honeydew and Glucose Honeys. — Method of Konig 
and Karsch.X — Dissolve 40 grams of honey in a cyhnder in water, and 

* The true polarization at 87° C. of a normal solution of glucose subjected to inversion 
and neutralization as above (but without the use of the clarifier), will be about 93% that 
of the direct polarization of the sample in the cold. Hence 175X0.93 = 162.7. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 110, p. 68. 

X Zeits. anal. Chem., 34, 1895, p. i. U. S. Dept. of Agric, Bur. of Chem., Bui. 1 10, p. 63. 



SUGAR AND SACCHARINE PRODUCTS. 



64: 



make up to 40 cc. Transfer 20 cc. of the homogeneous solution to a 
250-cc. flask and till to mark with absolute alcohol with slow addition and 
constant shaking, and then allow to stand two or three days, with occasional 
agitation. At the end of this time all the dextrin has settled out. After 
shaking the solution, filter and evaporate 100 cc. of the filtrate until free 
from alcohol. To the liquid residue add a little subacetate of lead and 
sodium sulphate, make up to 20 cc. with water, and polarize the filtered 
solution. Dextrorotatory natural honeys show by this method a levo- 
rotation ; honeys adulterated with dextrose or glucose to the extent of 
25% or more, a dextrorotation. In case the honey contains a large 
amount of sucrose, the solution should be inverted with hydrochloric acid 
before polarizing. 

BEESWAX. — The purity of beeswax is best established by determining 
its melting-point, its specific gravity, its saponification equivalent, and 
its refractometric reading. The melting-point of pure wax is about 
64° C, while that of paraffin, its chief adulterant, is from 52 to 55° C. 
Its saponification equivalent should be from 87.8 to 107, while that of 
])araffin is o. 

Method of Determining Specific Gravity of Beeswax *~~V\a.ce a weighed 
rod of the wax, about i to 1.5 cm. long by 0.5 cm. diameter, in an accurately 
marked 50-cc. flask, and run in water from a burette till the water level 
reaches the mark. 50 cc. minus the burette reading represent the vol- 
ume occupied by the wax. The rod should be made to lie flat on the 
bottom of the flask, so that the incoming water will force its end against 
the sides and prevent the end from rising above the mark. The weight 
of the rod, divided by its volume gives its specific gravity. The specific 
gravity of various mixtures of wax of 0.969 specific gravity and paraffin 
of 0.871 are given in the following table, prepared by Wagner, so that 
from the specific gravity of the mixture the percentage of paraffin can be 
calculated : 



Wax 

(Percentage). 


Paraffin 
(Percentage). 


Specific 
Gravity. 


Wax 

(Percentage). 


Paraffin 
(Percentage). 


Specific 
Gravity. 


25 
50 


100 

75 
50 


.871 

-893 
.920 


75 

80 

100 


25 
20 


-942 
.948 
.969 



The Refractometer Reading is most useful in establishing the purity 
of wax. Observations with this instrument are best made at 65° and 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 842. 



644 



FOOD INSPECTION AND AN/t LYSIS. 



great care should be taken in the case of the Zeiss butyro-refractometer 
not to exceed this temperature, or injury to the instrument may resuh. 
The Abb6 refractometer may be used with perfect safety and, when 
available, is to be preferred for the examination of beeswax. Many 
food laboratories are, however, not equipped with the Abbe, but nearly 
all find the butyro-refractometer indispensable. The latter instrument 
was primarily designed for such substances as butter and lard, so that the 




Fig. III. — ^Apparatus for Polarizing at High Temperatures. 



manufacturers did not intend it to be subjected to as high a temperature 
as 65°. They have, however, assured the author that if care be taken 
to bring the temperature very slowly and gradually to the required degree, 
65°, and to avoid also sudden -cooling, the cement that secures the prisms 
in place will not be appreciably affected; otherwise cracking or loosening 
of the cement would be liable to occur after a time. 



SUGAR AND SACCHARINE PRODUCTS. 645 

At 65° C. pure beeswax should have a reading on the butyro-refrac- 
tometer of 30 to 31.5,* while that of parafifiin is from 11 to 14.5.! 



CONFECTIONERY. 

The composition of confectioneiy is more complex than that of the 
saccharine products hitherto considered. As a rule, cane sugar, or one 
of its products, as molasses, forms the basis of most of the confections. 
Commercial glucose is also a common ingredient, while a large variety 
of such materials as eggs, butter, chocolate, various flavoring extracts, 
spices, nuts, and fruits, enter into the composition of confectionery. 

U. S. Standard Candy is candy containing no terra alba, barytes, 
talc, chrome yellow, or other mineral substances or poisonous colors or 
flavors, or other ingredients injurious to health. 

Adulteration. — Of late the adulteration of confectionery has been 
held largely in check by the National Confectioners' Association of the 
United States, which has fixed high standards of purity, and has been 
very zealous in restricting the use of harmful adulterants. 

Commercial glucose is not regarded as an adulterant of confectionery 
by the above-named association and by but few of the state laws. On the 
contrary, any ingredient, other than color, that has no food value, may 
logically be considered as an adulterant. Under this head are included 
such substances as parafiEin, as well as make-weight mineral matters, such 
3,s terra alba, talc, or calcium sulphate. 

I Most of the actually harmful ingredients employed in confectionery 
jhave been inherent in the coloring matters, or in the alcohol or fusel oil 
used in the manufacture of brandy drops and allied confections. 
I Colors in Confectionery. — A very wide range of colors is necessarily 
lemployed in the manufacture of confectionery, and the almost endless 
yariety of coal-tar dyes now available lend themselves most readily to 
the confectioner's needs. Elsewhere, under "colors," lists of injurious 
and non-injurious dyes are given as compiled by the National Confec- 
tioners' Association, though it is not always readily apparent how the lines 
jare drawn. 

j The tinctorial power of these dyes is so high that the actual amount 
of substance contained in a thin coating of the color on the outside of the 
candy is exceedingly small, so that it is doubtful whether serious cases of 
Injury have ever arisen from their use. 

* «£), 1.4452 tb 1,4463- t '•£), 1-4310 to 1.4335- 



646 FOOD INSPECTION AND ANALYSIS. 

Such was not the case formerly, before the prevalence of the coal-tar 
dyes, when such poisonous mineral pigments as chromate of lead were 
frequently used. Only one or two instances of the use of lead chromate 
in candy have come to the author's attention within ten years, since more 
satisfactory and harmless yellow colors among the azo-dyes are now 
obtainable. 

Analysis of Confectionery. — The following have been submitted 
by the author as provisional methods of procedure for the A. O. A. C.:* 

(i) Products of Practically Uniform Composition Throughout. — 
{a) Lozenges and Other Pulverizable Products. — Grind in a mortar or 
mill to a fine powder. For total solids, weigh from 2 to 5 grams of the 
powdered sample in a tared platinum dish, and dry in a McGill oven 
to constant weight. 

For Ash, ignite the residue from total solids in the original dish, 
observing the precautions given under sugar (p. 586), and molasses 
(p. 624). 

(b) Semi-plastic, Syrupy, or Pasty Products. — Weigh 50 grams of 
the sample into a 250-cc. graduated flask, mix thoroughly or dissolve, 
if soluble, in water, and fill to the mark. Be sure that the solution is 
uniform, or, if insoluble material is present, that it is evenly mixed by 
shaking before taking aliquot parts for the various determinations. For 
total solids and ash, measure 25 cc. of the above solution or mixture into 
a tared platinum dish, and proceed as directed under (a). 

(2) Confectionery in Layers or Sections of Different Composition. — 
When it is desired to examine the different portions separately, they 
should be separated mechanically with a knife, when possible, and treated 
as directed under (i). 

(3) Sugar-coated Fruit, Nuts, etc. — In case of a saccharine coating 
inclosing fruit, nuts, or any less readily soluble material, dissolve or 
wash off the exterior coating in water, which may, if desired, be evaporated 
to dryness for weighing, and proceed as in (i). 

(4) Candied or Sugared Fruits. — Proceed as in the examination of 
fruits (Chapter XXI). 

Detection of Mineral Adulterants. — As in the case of molasses, a 
considerable quantity, say 100 grams, should be reduced to an ash for 
examination for mineral adulterants, such as talc, calcium sulphate, and 
iron oxide, which are detected by regular qualitative tests. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 44. 



SUGAR AND SACCHARINE PRODUCTS. 647 

Detection of Lead Chromate. — Fuse the ash in a porcelain crucible 
with a mixture of sodium carbonate and potassium chlorate, boil the 
fused residue with water, neutrahze with acetic acid, filter, and treat the 
filtrate with barium chloride or lead acetate solution. A yellow pre- 
cipitate indicates a chromate. Treat the insoluble part of the fusion 
with nitric acid, and test for lead in the usual manner. 

If a drop of ammonium sulphide be applied to a piece of confectionery 
colored with lead chromate, it will produce a black coloration. 

Determination of Ether Extract. — The ether extract includes the fat 
derived from chocolate, eggs, or butter, as well as any paraffin present. 
Measure 25 cc. of the 20% solution (i) (h) (p. 646) into a very thin, 
readily frangible glass evaporating-shell (Hoffmeister^s Schdlchen), con- 
taining 5 to 7 grams of freshly ignited asbestos fiber; or, if impossible to 
thus obtain a uniform sample, weigh out 5 grams of the mixed, finely 
divided sample into a dish, and wash with water into the asbestos in the 
evaporating-shell, using, if necessary, a small portion of the asbestos 
fiber on a stirring-rod to transfer the last traces of the sample from dish 
to shell. Dry to constant weight at 100°, after which cool, wrap loosely 
in smooth paper, and crush into rather small fragments between the 
fingers, carefully transferring the pieces with the aid of a camel's-hair 
brush to an extraction-tube, or to a Schleicher and Schull cartridge for 
fat extraction. Extract with anhydrous ether or vdth petroleum ether in 
a continuous extraction apparatus for at least twenty-five hours. Trans- 
fer the solution to a tared flask, evaporate the ether, dry in an oven at 
100° C. to constant weight, and weigh. 

Determination of Paraffin. — Add to the ether extract in the flask, as 
above obtained, 10 cc. of 95% alcohol, and 2 cc. of i : i sodium hydroxide 
solution, connect the flask with a reflux condenser, and heat for an hour 
on the water-bath or until saponification is complete. Remove the con- 
denser, and aflow the flask to remain on the bath till the alcohol is evapo- 
rated off, and a dry residue is left. Treat the residue with about 40 cc. 
of water, and heat on the bath, with frequent shaking, till everything 
soluble is in solution. Wash into a separatory funnel, cool, and extract 
with four successive portions of petroleum ether, which are collected in 
a tared flask or capsule. Remove the petroleum ether by evaporation, and 
dry in the oven to constant weight. 

It should be noted that any phytosterol or cholesterol present in the 
fat would come down with the paraffin, but the amount would be so 
insignificant that, except in the most exacting work, it may be disregarded. 



04H h'OOl) /NPSECT.'ON AND ANALYSIS. 

The (haracUr of the final residue should, however, be confirmed by 
(Iclcrmininf^ its melling-])()int and specific gravity, and by subjecting it 
to cxaniinalioii in llic bulyro-refractometer. The melting-point of par- 
affin is about 5.1.5" C; its si)e(ific gravity at 15.5° C. is from 0.868 to 0.915, 
and on the butyro-refractometer the reading at 65° C. is from 11 to 14.5. 

Determination of Starch. — Measure gradually 25 cc. of a 20% aqueous 
solution or uniform mixture of the sample into a hardened filter or Oooch 
crucible, or transfer by washing 5 grams of the finely ])owdered substance 
to Ihc fihcr or Gooch, and allow the residue on the filter to become air- 
dried. I''.\tra(t with i"ive successive ])oriions of 10 cc. of ether, then 
wash with 150 cc. of 10% alcohol, and finally with 20 cc. of strong alcohol. 
Transfer the residue to a large flask and boil gently for four hours with 
200 cc. of water and 20 cc. of hydrochloric acid (specific gravity 1.125), 
the flask being ])r()vided with a reflux condenser. Cool, neutralize with 
sodium hydroxide, add 5 ( c of alumina cream, and make up the volume 
to 250 cc. with water, I-'ilUr and determine the dextrose in an aliquot 
part of the filtrate by any of the various Fehling methods. Hie weight 
of the dextrose nuillii)licd by 0.9 gives the weight of the starch. 

Polarization of Confectionery. As a clarifur use either alumina 
cream or subacetate of lead, according to ihe nature and opacity of the 
sample. Ordinarily alumina cream is best, 1)ul in dark-colored samples, 
or those in which molasses has been used, it is sometimes necessary to 
emj)loy the subacetate. When starch is absent, and the sample is practi- 
cally soluble, ])olarize and invert in the usual manner (p. 588). Where 
consi(leral)le starch or insoluble matter is jiresent, use the double-dilution 
method of Wiley and Ewell Q). 620), thus making due allowance for 
the volume of the jirec ii)ilale. 

Cane sugar, invert sugar, and dextrin, arc determined as directed 
for honey. 

Commercial glucose is roughly determined by j)()lari/ing the sample 
at 87° C, as in the case of honey ([>. 639). 

Confectionery is made in such a wide variety of forms, and these differ 
in consistency to such an extent that commercial glucose of all available 
degrees of density can be utilized to advantage in one i)roducl or another. 
In this respect confectionery is unlike honey and molasses, wherein a 
fairly uniform grade of commercial glucose is necessarily used for 
mixing, this grade being naturally selected with reference to its similarity 
in density to the molasses. On this account the glucose factor used 



SUGAR /'.ND S/1CCHARINE PRODUCTS. 649 

for honey and molasses (175) may in some varieties of confectionery be 
too high. 

Determination of Alcohol in Syrups Used in Confectionery. — (Brandy- 
drops.) — Open each drop by cutting off a seaion with a sharp knife, and 
collect in a beaker the syrup of from 15 to 25 of the drops, which 
will usually yield from 30 to 50 grams of syrup. Strain the syrup into 
a tared beaker through a perforated porcelain filter-plate in a funnel 
to separate from particles of the inclosing shell, and ascertain the weight 
of the syrup. Wash into a distilling-flask, dilute with half its volume 
of water, and distil off into a tared receiving-flask a volume equal to the 
original volume of syrup taken. Ascertain the weight of the distillate 
and its specific gravity by means of a pycnometer. Multiply the per- 
centage by weight of alcohol corresponding to the specific gravity, as 
found in the tables on page 661 et seq., by the weight of the distillate, and 
divide this by the weight of syrup taken. The result Is the per cent by 
weight of alcohol in the syrup. 

Detection of Colors. — It is somedmes necessary to macerate a con- 
siderable mass of the material to remove the color, which is, however, 
in the majority of cases readily soluble. The insoluble colors are nearly 
all mineral pigments to be looked for in the ash, as in the case of chromate 
of lead (p. 647). Frequently the coloring matter is confined to a thin 
outer layer, which is readily washed off. 

The solution of the dyestuff is examined as directed under colors. 

Detection of Arsenic. — Arsenic may be present through impure 
coloring-matter. If the color is confined to an exterior coating, this 
should be washed off and examined. If distriVjuted through the mass, 
a solution of the whole should be taken. Examine for arsenic by the 
Gutzeit or Marsh method, as direaed imder glucose (p. 632). 



650 FOOD INSPECTION AND ANALYSIS. 



REFERENCES ON SUGARS. 

Babington, F. W. Sugars, Syrups, and Molasses. Can. Inl. Rev. Dept., Bui. 

25- 

Maple Syrup. Can. Inl. Rev. Dept., Bui. 45. 

Bartley, E. H., and Mayer, J. L. Identification of Carbohydrates. Merck's Report, 

12, 1903, p. 100. 
Brown, H. T., Morris, G. H., and Millar, J. H. Experimental Methods Employed 

in the E.xamination of the Products of Starch Hydrolysis by Diastase. Jour. 

Chem. Soc. Trans., 71 (1897), p. 72. 
Browne, C. A. The Analysis of Sugar Mi.xtures. Jour. Am. Chem. Soc, 28, 1906, 

P- 439- 
— — Chemical Analysis and Composition of American Honeys. U. S. Dept. of Agric, 

Bur. of Chem., Bui. no. 
The Unification of Saccharimetric Observations. A. O. A. C. Proc. 1908. U. S. 

Dept. of Agric, Bur. of Chem., Bui. 122, p. 221. 
Bryan, A. H. The Estimation of Dry Substance by the Refractometer 

in Liquid Saccharine Food Products. Jour. Am. Chem. Soc, 30, 1908, 

p. 1443. 
Methods for the Analysis of Maple Products and the Detection of Adulterants, 

together with the Interpretation of Results Obtained. U. S. Dept. of Agric,. 

Bur. of Chem., Circ. No. 40. 
DoOLiTTLE, R. E., and Seeker, A. F. The Possibilities of Muscovado Sugar as an 

Adulterant for Maple Products. A. O. A. C. Proc. 1908. U. S. Dept. of AgriC;. 

Bur. of Chem., Bui. 122, p. 196. 
Notes on the Winton Lead Number of Mixtures of Cane and Maple Syrup. 

Ibid., p. 198. 
Frankel and Hutter. Starch, Glucose and Dextrin. Phila., 1881. 
Fresenius, W. Der Starkesirup bei Zubereitung von Nahrungs- und Genussmitteln. 

Zeits. Unters. Nahr. Genuss., 2, 1899, pp. 35 u. 279. 
Fruhling, R. Anleitung zur Untersuchung der fiir die Zuckerindustrie. 6th ed. 

Braunsweig, 1903. 
Hiltner, R. S., and Thatcher, R. W. An Improved Method for the Rapid 

Estimation of Sugar in Beets. Jour. Am. Chem. Soc, 23, 1901, p. 

299. 
Horne, \V. D. The Chemical Determination of Sulphites in Sugar Products. U. S. 

Dept. of Agric, Bur. of Chem., Bui. 105, 1906, p. 125. 
HoRTVET, J. The Chemical Composition of Maple-Syrup and Maple-Sugar, Methods 

of Analysis, and Detection of Adulteration. Jour. Am. Chem. Soc, 26, 1904, 

P- 1523- 



SUG^R /1ND SACCHARINE PRODUCTS. 651 

Jones, C. H. Detection of Adulteration in Maple Sugar and Maple Syrup. Vt. Agric. 

Exp. Sta. Rep., 1903, p. 446. 
Maple Syrup and Maple Sugar Investigations with Particular Reference 

to the Detection of Adulteration. Vt. Agric. Exp. Sta. Rep., 1904, p. 

315- 
Landolt, H. Handbook of the Polariscope and its Practical Applications, 

1882. 
Trans, by Long, J. H. Optical Rotation of Organic Substances. Easton, 

1902. 
Leach, A. E. The Determination of Commercial Glucose in Molasses, SyruDS and 

Honey. Jour. Am. Chem. Soc, 25, 1903, p. 982. 

Saccharine Products. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 43. 

Lock and Newlands. A Handbook for Planters and Refiners. London, 1888. 

MACF.A.RLANE, T. Honey. Can. Inl. Rev. Dept., Bui. 45. 

MuNSON, L. S., and Walker, P. H. The Unification of Reducing Sugar Methods. 

Jour. Am. Chem. Soc, 28, 1906, p. 663. 
Robin, L. Sucres. Analyse des Matieres Alimentaires (Girard et Dupre), p. 525. 

Paris, 1894. 
Roth, H. L. A Guide to the Literature of Sugar. London, 1890. 
Sachsse, R. Die Chemie der Kohlenhydrate. Leipzig, 1877. 
Sawyer, H. E. The Commercial Analysis of Molasses. Jour. Am. Chem. Soc, 27, 

1905, p. 691. 
Shutt, F. F., and Charron, A. T. Determination of Moisture in Honey. Trans. 

Royal Soc. Canada, 2d Series, 1902-3, 7, Section 3. 
SiDERSKY, D. Traite d' Analyse des Matieres Sucrees. Paris, 1890. 
Spencer, G. L. Handbook for Sugar Manufacturers and their Chemists. New- 
York, 1897. 
Steydn, E. Die Untersuchung des Zuckers und Zuckerhaltiger StoiTe. Leipzig, 

1893. 
Sy, a. p. Note on the Examination of Maple Products — The Lead Value. J. Frank. 

Inst., 162, p. 71. 
Three New Preliminary Tests for Maple Products. Jour. Am. Chem. Soc, 30, 

1908, p. 1429. 
ToLLENS, B. Handbuch der Kohlenhydrate. Breslau, 1888. 
ToLMAN, L. M., and Smith, W. B. Estimation of Sugars by Means of the Refrac- 

tometer. Jour. Am. Chem. Soc, 28, 1906, p. 1476. 
Tucker, J. H. Manual of Sugar Chemistry. New York, 1890. 
Walker, P. H. The Unification of Reducing Sugar Methods. Jour. Am. Chem. 

Soc, 29, 1907, p. 541. 
Weichmann, F. S. Sugar Analysis. New York, 1890. 
Wein, E. Tabellen zur quantitativen Bestimmung der Zuckerarten. 
Trans, by Frew, W. Tables for the Quantitative Estimation of the Sugars. 

London, 1896. 
Wiley, H. W. Sugar, Molasses and Syrup, Confections, Honey and Beeswax. U. S 

Dept. of Agric, Div. of Chem., Bui. 13, part 6. 



652 FOOD INSPECTION /INI) /IN A LYSIS. 

Wiley, H. W. The Influence of TemiK-ralure on the Si)e(iric Rotation of Sucrose 

and Method of Correcting Readings of CoiTij)ensating Polariscopes Therefor. 

Jour. Am. Chem. Soc, 21, 1899, p. 568. 
WiNTON, A. I.. A Method for the Determination of Lead Number in Maple Syrup 

and Ma|)ii' Sugar. Jour. Am. Chem. Soc, 28, igo6, j;. 1204. 
Young, W. J. A Microscojjic Study of Pollen. U. S. Dept. of Agric, Hur. of Chem., 

Bui. no. 



CHAPTER XV. 

ALCOHOLIC BEVERAGES. 

Alcoholic Fermentation. — In a broad sense all alcoholic liquors are 
saccharine products, in that they are essentially the result of the fermen- 
tation of sugar. In the case of fruits, the sugar already exists as such 
in their juices, which, when expressed, almost immediately on exposure 
to the air begin to undergo spontaneously the process of alcoholic fermen- 
tation, in accordance wilh the reaction: 

(i) C«H,20«=2QH«0+2C03. 

Dextrose or Alcohol Carbon 

grape sugar dioxide 

In the case of grains the process is more complex, involving a preliminary 
saccharous fermentation, whereby the starch is first transformed into 
sugar. 
Thus 

(2) 2CeH,.A+ H^O = C,H. A + C«H^Oe. 

Starch Dextrin Dextrose 

(3) CeH,o05+H,0 = C,H„Oe. 

Dextrin Dextrose 

The process of alcoholic or vinous fermentation is largely dependent 
upon the presence of various species of yeasts, which either exist from 
the first in the expressed juices themselves, as in the case of wines, being 
derived from the skins of the grapes and from the air, or are introduced 
with some degree of selection, as in the case of beer. 

In the juices of most fruits the sugar exists in the form of sucrose, 
mixed wilh variable amounts of invert sugar resuhing from the inver- 
sion of the sucrose due to the action of ferments, such as invertase, a 
soluble ferment of yeast. The invert sugar nearly always predominates, 
and in some juices, as for instance the grape, nearly all the sugar has been 
inverted. 

6S3 



654 FOOD INSPECTION AND ANALYSIS. 

The above reaction, No. i, illustrating the splitting up of grape sugar 
into alcohol and carbon dioxide, does not represent the practical yield 
of alcohol under ordinary conditions that occur in vinous fermentation, 
for, as a matter of fact, instead of 51.11 parts of alcohol and 48.89 parts 
carbon dioxide, which would theoretically result as above from the fer- 
mentation of 100 parts of dextrose, only about 95% of the theoretical 
yield can be obtained, so that in practice it is possible to form but about 
48.5% alcohol and 46.5% carbon dioxide. The balance, amounting 
to some 5%, consists chiefly of glycerin, succinic acid, and traces of 
various compounds, including some of the higher-boiling alcohols (propyl, 
butyl, and amyl) and their ethers, which form the fusel oil of the dis- 
tilled liquors. 

Vinous fermentation takes place most readily in slightly acid liquids, 
at a temperature ranging from 25° to 30° C. 

It is convenient to divide alcoholic beverages into two main groups, 
first the fermented and second the distilled liquors. The fermented 
liquors naturally subdivide themselves into (a) the products of the direct 
spontaneous fermentation of saccharine fruit juices, such, for example, 
as those of the apple and the grape, to form cider and wine respectively, 
and (h) the malted and brewed liquors,, such as beer and ale, produced 
by the conversion of the starch of grain inLo sugar, and the final alcoholic 
fermentation of the latter. 

The distilled liquors include such products as whiskey, brandy, rum, 
and gin, wherein alcoholic infusions prepared by previous fermentation 
in various ways are further subjected to distillation. 

Alcoholic Liquors and State (or Municipal) Control. — The mere 
adulteration of liquors does not constitute the only feature which brings 
them within the scope of the public analyst's work and renders them 
especially amenable to stringent laws. Indeed, it is often a far more 
important question for the analyst to decide by his results whether or 
not the samples submitted to him, by police seizure or otherwise, are 
sold in violation of the regulations in force in his particular locality govern- 
ing the liquor traffic. 

A common regulation in no-license localities fixes the maximum per 
cent of alcohol which shall decide whether or not a liquor is legally a 
temperance drink, and can be sold as such with impunity. From its low 
content in alcohol, an analyst's findings regarding a certain sample may 
exonerate the dealer suspected of violating this law, while yet by the 
very reason of its being low in alcohol the same sample would be placed 



ALCOHOLIC BEyERAGES. 655 

in the adulterated list as regards non-conformance to a standard of purity. 
While the raising of revenue is one purpose for the existence of these 
laws bearing on liquor license, an equally important object sought to be 
gained is doubtless the repression of intemperance. 

Toxic Effects. — A popular impression seems to exist that the toxic 
effec.s of an adulterated liquor are far worse from a temperance stand- 
point than those of a sample of good standard quality, and it is a common 
experience of the public analyst to have submitted to him by well-mean- 
ing temperance advocates samples which are alleged to have caused 
the worst forms of intoxication, and are thus suspected of being impure. 
As a matter of fact the chief adulterants of liquors are water, sugar, and, 
in the case of beer, various bitter principles and vegetable extractives, 
none of which are on record as being in themselves actively toxic* 

Alcohol is the one ingredient of liquor which, more than any other, 
produces a marked physiological effect. Many liquors, especially those 
of the distilled variety classed as adulterated, are so considered by reason 
of their low alcoholic content through watering or otherwise, hence this 
commonest form of adulteration, far from being detrimental in itself, is 
actually helpful to the temperance cause. 

Details of Liquor Inspection. — The same precautions should be 
carefully observed by officers making seizures of liquors for analysis, 
as by food inspectors, regarding safe delivery of the samples to the 
analyst. The following instructions are circulated by the State Board 
of Health of Massachusetts, which has in charge the inspection of liquors, 
concerning the taking of samples in that state and the transmission to 
the analyst: 

DIRECTIONS rOR TAKIXG SAMPLES FOR ANALYSES. 

The officer making a seizure, or taking samples of beer, should note 
at the time of such seizure the general appearance of the liquor, — as to 
whether it is clear or cloudy, whether it is still or has a strong head. 

If the liquor is in bottles, take at least one pint bottle; if in barrels, 
draw a pint bottle from each. Request the owner to seal each sample 
taken. If the bottles have cork stoppers, cut the stoppers off level with 
the top of the bottle and cover with wax; if with patent stoppers, a little 
wax placed vpon the wire at the point where it lays against the neck of 
the bottle is sufficient. If the owner refuses to seal it, then the officer 

* The writer refers to substances intentionally added, and not to accidental impurities, 
such as arsenic, etc., that are occasionally found. 



656 FOOD INSPECTION AND ANALYSIS. 

should seal it in his presence, calling his attention to the fact. Before 
leaving the premises, place upon the bottle a label or tag, with the date, 
the name of the owner, and the name of the officer upon it, and also the 
name of the town or city. Then place in a box, with the certificate 
required by law, and forward without delay to the analyst. 

FORM OF LABEL. 



Town 

Date of seizure 19 

Owner 

Kind of liquor 

Brewer 

Accompanying each sample is a certificate like the following, the 
first part of which is filled out and signed by the officer, while the second 
part, containing the data of analysis, is filled out and signed by the analyst 
and returned by him to the officer. Such a certificate is nearly always 
accepted as evidence in court without the personal appearance of the 
analyst. 

ss 19 . 

To the State Board of HeaUh: 

I send herewith a sample of 

taken from liquors seized by me 19 . 

Ascertain the percentage of alcohol it contains, by volume, at sixty 
degrees Fahrenheit, and return to me a certificate herewith upon the 
annexed form. 
Seized from 



Officer. 

COMMONWEALTH OF MASSACHUSETTS. 

No 

Office of the State Board of Health. 

Boston, 19 . 

This is to certify that the received by me 

with the above statement contains per cent of alcohol, 

by volume, at sixty degrees Fahrenheit. '°° 

Received 19 . 

Analysis made 19 . 



[seal.] Analyst State Board of Health. 



ALCOHOLIC BEVERAGES. 657 

A convenient method for recording analyses is by the employment 
of numbered library cards, which bear the same number as the certificates 
and are kept by the analyst. 

The following is a convenient form: 

No Analyzed 

County Wt. flask and ale '.'....'. 

City or town Wt. flask 

Ofiicer Wt. ale '.V.'.'.'.W 

Defendant Sp.gr. ale. (60°) \\ 

Address Per cent alcohol .'.'.".'.' 

Kind of liciuor Reported \\ 

Seized 

Received 

How delivered 

Sealed 

Condition 

Kind of bottle 

Registered 

METHODS OF ANALYSIS COMMON TO ALL LIQUORS. 

Specific Gravity. — This should be taken at 15.6° or calculated to 
that temperature. The most convenient mode of procedure is to bring 
the temperature of the sample somewhat below that point by allowing 
the flask containing it to stand in cold water, and to have everything in 
readiness to make the determination when 15.6° temperature has been 
reached, either by the hydrometer spindle in a glass cylinder, by the 
Westphal balance, or by the pycnometer. The latter is by far the most 
accurate, especially if it is of the form which is fitted with a thermometer- 
stopper. 

Detection of Alcohol. — It is rarely necessary to make a qualitative 
test for alcohol in liquors, since it is almost invariably present even in 
many of the so-called temperance drinks, at least in small amount. 
Indeed in many localities a beverage is legally a temperance drink that 
contains not more than 1% alcohol by volume. 

The lodojorm Test. — Alcohol, when present in aqueous solution to 
the extent of 0.1% or more, may be detected by the iodoform test. The 
solution is warmed in a test-tube with a few drops of a strong solution 
of iodine in potassium iodide, after which enough sodium hydroxide 
solution is added to nearly decolorize. On standing for some time a 
yellow precipitate of iodoform will appear if alcohol be present, or at 
once if there is a considerable amount, and the characteristic odor of 
iodoform will be rendered apparent, even when the precipitate is so slight 
as to be almost imperceptible. This iodoform precipitate is crystalline, 
showing under the microscope as star-shaped groups or hexagonal tablets. 



65S FOOD INSPECTION /tND ANALYSIS. 

It should not be forgotten that other substances than alcohol give the 
reaction, as lactic acid, acetone, and various aldehydes and ketones. 

Pure methyl or amyl alcohol or acetic acid do not thus react. 

Berthelot recommends benzoyl chloride as a reagent for detecting 
alcohol. By warming a mixture of a few drops of benzoyl chloride with 
the solution to be tested, and adding a little sodium hydroxide, ethyl 
benzoate is formed, recognizable by its distinctive odor. This reaction 
is delicate to 0.1% alcohol. The presence of other alcohols than ethyl 
produces ethers of characteristic odor. 

Hardy s Test for Alcohol consists in shaking the aqueous solution 
with some powdered guaiacum resin, filtering, and adding to the filtrate 
a little hydrocyanic acid and a drop of dilute copper sulphate solution. 
A blue coloration considerably deeper than that due to the copper salt 
is indicative of alcohol. 

Methyl Alcohol in spirits is tested for as described on pp. 749-752. 

Determination of Alcohol. — In the case of carbonated liquids it is 
necessary to first expel the free carbon dioxide, which is readily accom- 
plished by pouring the liquor back and forth from one beaker to another, 
from time to time removing the excess of froth from the top of the vessel 
by the aid of the hand. Or, the sample may be shaken vigorously in a 
large separatory funnel, and the still liquor drawn off from below the 
froth, repeating the operation several times if necessary. In either 
case the mechanical treatment should be continued till the liquor is com- 
paratively quiet and free from foam. 

(i) By Distillation. — This is by far the most accurate method of 
determining alcohol, and should be carried out in all cases where any 
legal controversy is apt to be involved. Into a flask of 250 to 400 cc. 
capacity introduce a convenient quantity of the liquor, which should be 
accurately weighed or measured, according to whether the percentage 
by weight or measure is desired. The following are suitable quantities: 
Distilled hquors, 25 grams or cc; cordials, 25 to 50 grams or cc; wines, 
ciders, and malt liquors, 100 grams or cc. In the case of wines or 
ciders which have undergone acetic fermentation, add o.i to 0.2 gram of 
precipitated calcium carbonate or neutralize with standard alkali. 

Dilute the liquid to 150 cc. and distil into a loo-cc flask. Nearly 
all alcoholic liquors, if comparatively free from carbon dioxide, will 
boil without undue frothing or foaming. New wine will occasionally 
give trouble in this regard, but foaming may usually be prevented in this 



ALCOHOLIC REVERAGES. 659 

case by the addition of tannic acid. In case of wine, cider, and beer 
all the alcohol will have passed over in the first 75 cc. of the distillate, 
or three-fourths the original measured volume, but with distilled liquors 
high in alcohol the process had better be continued till nearly 100 cc. or 
the original volume taken have passed over. If the condenser is of glass, 
one can observe when all the alcohol has been distilled over, for the reason 
that the mixed alcohol and water vapors in the upper portion of the con- 
denser present a striated or wavy appearance, readily apparent so long 
as the alcohol is passing over, while after all the alcohol has been distilled, 
the condenser-tube appears perfectly clear. The distillation is thus 
continued for some time after this striated appearance has ceased. The 
distillate in the receiving glass is finally made up to the mark or to the 
original volume of the liquor taken. Strictly speaking, the measure- 
ments before and after distillation should be made at 15.6° C, but, except- 
ing in case of distilled liquors, no appreciable error results from making 
both measurements at the same or room temperature. Another precau- 
tion formerly thought necessary was to have the deliver}'-tube from the 
condenser pass below the level of a little water in the receiving-flask 
from the start, but equally accurate results have been obtained by simply 
allowing the end of the condenser-tube to enter the narrow-necked flask. 

Fig. 112 shows a bank of six stills of the kind used in the author's 
laboratory for alcohol determination in liquors. In each still the verti- 
cal glass worm-condenser, the round-bottomed distilling-flask, and the 
lamp, are supported by rings held by a single upright rod. The receiving- 
flask is readily connected with the condenser by means of a single bent 
tube provided with a rubber stopper. The cold-water pipe supplying 
the condensers is shown at the top, and the gas-supply pipe at the bottom. 

The distillate, made up to 100 cc, is thoroughly shaken and its 
specific gravity taken at exactly 15.6° in a pycnometer, or by the Westphal 
balance. From the specific gravity the corresponding percentage of 
alcohol by weight or volume, or the grams per 100 cc. in the distillate, 
is ascertained by reference to the accompanying tables. 

To obtain percentage of alcohol by weight in the sample, multiply 
the per cent by weight in the distillate by the weight of the distillate, and 
divide by the weight of the sample taken ; to obtain per cent by volume, 
multiply the per cent by volume in the distillate by 100, and divide by 
the volume of the sample used. 

(2) From the Specific Gravity of the Sample. — In the case of dis- 
tilled liquors having very little residue, an approximation to the true 



66o FOOD INSPECTION yIND ^N^ LYSIS. 

percentage of alcohol may be obtained by using the alcohol table in con- 
nection with the specific gravity of the liquor itself. The accuracy of 
this method depends largely on the freedom from residue, being absolutely 
correct for mixtures of alcohol and water only. 

(3) By Eva porat ion. ^Determme the specific gravity of the sample, 
evaporate a measured portion of the liquor (50 or 100 cc.) in a porcelain 




Fig. 112. — Bank of Stills for Alcohol Determination. 

dish over the water-bath to one-fourth its bulk, make up to its original 
volume with distilled water, and determine the specific gravity of this 
second or dealcoholized portion. Add i to the original specific gravity, 
and from this subtract the second specific gravity. The difference is 
the specific gravity corresponding to the alcohol in the liquor, the per 
cent of which is found from the table. 

Example. — Suppose the specific gravity of the original sample to be 
0.9900 while that of the dealcoholized sample is 1.0009. Then 1.9900 — 
1.0009 = 0.9891. .'. Per Cent by volume of alcohol = 8. 10. 



ALCOHOLIC BEyE RAGES. 



66] 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL. 
(According to Hehner.) 



Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 
















] ' — • 


Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 
Cent 


Pel 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 

Cent 


Per 

Cent 


Grams 


bv 


by Vol- 


per 
100 cc. 


by 


by Vol- 


per 


by 


by Vol- 


per 




Weight 


ume. 






Weight 


ume. 






Weight 


ume. 


1 00 cc. 


I.OOOO 


0.00 


0.00 


0.00 


















0.9999 


0.05 


0.07 


0.05 


0.9959 


^■ii 


2-93 


2.32 


0.9919 


4.69 


5-86 


4-65 


8 


O.II 


0.13 


O.II 


8 


2-39 


3.00 


2.38 


8 


4-75 


5-94 


4.71 


7 


0.16 


0.20 


0.16 


7 


2.44 


3-07 


2-43 


7 


4.81 


6.02 


4-77 


6 


0.21 


0.26 


0.21 


6 


2.50 


3-14 


2-49 


6 


4.87 


6.10 


4-83 


5 


0.26 


0-33 


0.26 


5 


2.56 


3.21 


2-55 


5 


4-94 


6.17 


4.90 


4 


0.32 


0.40 


0.32 


4 


2.61 


3-28 


2.60 


4 


5.00 


6.24 


4-95 


3 


0-37 


0.46 


0-37 


3 


2.67 


3-35 


2.65 


3 


5.06 


6.32 


5-01 


2 


0.42 


0-53 


0.42 


2 


2.72 


3-42 


2.70 


2 


5-12 


6.40 


5-07 


I 


0.47 


C.60 


0.47 


I 


2.78 


3-49 


2.76 


I 


5-19 


6.48 


5-14 





0.53 


0.66 


0-53 





2-83 


3-55 


2.81 





5-25 


6-55 


5-20 


0.9989 


0.58 


0-73 


0.58 


0.9949 


2.89 


3.62 


2.87 


0.9909 


5-31 


6-63 


5.26 


8 


0.63 


0.79 


0.63 


8 


2.94 


3-69 


2.92 


8 


5-37 


6.71 


5-32 


7 


0.68 


0.86 


0.68 


7 


3.00 


3-76 


2.98 


7 


5-44 


6.78 


5-39 


6 


0.74 


0-93 


0.74 


6 


3.06 


3-83 


3-04 


6 


5-50 


6.86 


5-45 


5 


0.79 


0.99 


0.79 


5 


3-12 


3-90 


3.10 


5 


5-56 


6-94 


5-51 


4 


0.84 


1.06 


0.84 


4 


3.18 


3-98 


3.16 


4 


5.62 


7.01 


5-57 


3 


0.89 


1-13 


0.89 


3 


3-24 


4-05 


3-22 


3 


5-69 


7.09 


5-64 


2 


0-95 


1. 19 


0-95 


2 


3-29 


4.12 


3-27 


2 


5-75 


7.17 


5-70 


I 


1. 00 


1.26 


1. 00 


I 


3-35 


4.20 


i-2,3 


I 


5-81 


7-25 


5-76 





1.06 


1-34 


1.06 





3-41 


4-27 


3-39 





5-87 


7-32 


5.81 


0.9979 


1. 12 


1.42 


1. 12 


0.9939 


3-47 


4-34 


3-45 


0.9899 


5-94 


7.40 


5-88 


8 


1. 19 


1-49 


1. 19 


8 


3-53 


4-42 


3-51 


8 


6.00 


7.48 


5-94 


7 


1.25 


1-57 


1.25 


7 


3-59 


4-49 


3-57 


7 


6.07 


7-57 


6.01 


6 


1-31 


1-65 


1-31 


6 


3-65 


4-56 


3-63 


6 


6.14 


7.66 


6.07 


S 


1-37 


1-73 


1-37 


5 


3-71 


4-63 


3-69 


5 


6.21 


7-74 


6.14 


4 


1-44 


1. 81 


1-44 


4 


3-76 


4.71 


3-74 


4 


6.28 


7-83 


6.21 


3 


1-50 


1.88 


1.50 


3 


3.82 


4-78 


3-80 


3 


6.36 


7-92 


6.29 


2 


1.56 


1.96 


1.56 


2 


3-88 


4-85 


3-85 


2 


6.43 


8.01 


6.36 


I 


1.62 


2.04 


1. 61 


I 


3-94 


4-93 


3-91 


I 


6.50 


8.10 


6-43 





1.69 


2.12 


1.68 





4.00 


5.00 


3-97 





6.57 


8.18 


6.50 


0.9969 


1-75 


2.20 


1-74 


0.9929 


4.06 


5.08 


4-03 


0.9889 


6.64 


8.27 


6-57 


8 


1. 81 


2.27 


1.80 


8 


4.12 


5.16 


4.09 


8 


6.71 


8.36 


6.63 


7 


1.87 


2-35 


1.86 


7 


4.19 


5-24 


4.16 


7 


6.78 


8.45 


6.70 


6 


1-94 


2.43 


1-93 


6 


4-25 


5-32 


4.22 


6 


6.86 


8-54 


6.78 


5 


2.00 


2-51 


1.99 


5 


4-31 


5-39 


4.28 


5 


6-93 


8.63 


6.85 


4 


2.06 


2.58 


2-05 


4 


4-37 


5-47 


4-34 


4 


7.00 


8.72 6.92 


3 


2. II 


2.62 


2.10 


3 


4-44 


5-55 


4.40 


3 


7.07 


8.80 


6-99 


2 


2.17 


2.72 


2.16 


2 


4-50 


5-63 


4.46 


2 


7-13 


8.88 


7-05 


I 


2.22 


2-79 


2.21 


I 


4-56 


5-71 


4-52 


I 


7 20 


8.96 


7.12 





2.28 


2.86 


2.27 





4.62 


5-78 


4-58 





7-27 


9.04 


7.19 



662 



FOOD INSPECTION /1ND ANALYSIS. 



SPECIFIC GRAVITY AND PERCENTAGE OF KLCOnOl.— {Continued). 



Spec. 
Grav. 

at 
15.6° C. 



0.9879 
8 

7 
6 

S 
4 



0.9869 

8 

7 
6 

5 
4 



I 
o 

0.9859 
8 

7 
6 

5 
4 
3 
2 
I 
O 

0.9849 

8 

7 
6 

5 
4 
3 
2 
I 
o 



Absolute Alcohol. 



Per 

Cent 

bv 

Weight 



0.9839 

8 
7 



7-33 
7.40 

7-47 
7-53 
7.60 
7.67 

7-73 
7.80 
7.87 
7-93 

8.00 
8.07 
8.14 
8.21 
8.29 
8.36 

8.43 
8.50 

8.57 
8.64 

8.71 

8-79 
8.86 

8.93 
9.00 
9.07 
9.14 
9.21 
9.29 
9-36 

9-43 
9-50 
9-57 
9.64 
9.71 

9-79 
9.86 

9-93 
10.00 
10.03 



10.15 

10.23 

10.31 

610.38 

5 10.46 

4 10.54 

3 10.62 

10.69 

10.77 

10.85 



Per 
Cent 

by Vol- 
ume. 



9-13 
9.21 
9.29 



9.70 
9.78 
9.86 

9-95 
10.03 
10. 12 
10.21 
10.30 
10.38 
10.47 
10.56 
10.65 
10-73 

10.82 
10.91 
11.00 
11.08 
11.17 
11.26 

11-35 
11.44 
11.52 
11.61 

11.70 
11.79 
11.87 
11.96 
12.05 
12.13 
12.22 
12.31 
12.40 
12.49 

12.58 
12.68 
12.77 
12.87 
12.96 
13-05 
13-15 
13.24 

13-34 
13-43 



Grams 
per 



7.24 


7-31 


7-37 


7-43 


7-50 


7-57 


7-63 


7.70 


7-77 


7-83 


7.89 


7.96 


8.04 


8.10 


8.17 


8.24 


8.31 


8.38 


8.45 


8.52 


8.58 


8.66 


8.73 


8.80 


8.87 


8-93 


9.00 


9-07 


9.14 


9.22 


9.29 


9-35 


9.42 


9-49 


9-56 


9.64 


9.71 


9-77 


9.84 


9.92 


9-99 


10.06 


10.13 


10.20 


10.28 


10.36 


10.44 


10.51 


IO-59 


10.67 



Spec. 
Grav. 

at 
15.6° C. 



0.9029 
8 

7 
6 

5 
4 
3 



0.9819 

8 

7 
6 

5 

4 



Absolute Alcohol. 



Per 

Cent 

by 

Weight 



0.9799 

8 

7 
6 

5 
4 



0.9789 
8 

7 
6 

5 
4 



10.92 
11.00 
11.08 
11.15 
11.23 
11.31 
11.38 
11.46 

11-54 
11.62 

11.69 
11.77 
11.85 
11.92 
12.00 
12.08 
12.15 
12.23 
12.31 
12.38 

12.46 

12-54 
12.62 
12.69 
12.77 
12.85 
12.92 
13.00 
13.08 
13-15 

13-23 

13-38 
13.46 

13-54 
13.62 
13.69 
13-77 
13-85 
13.92 

14.00 
14.09 
14.18 
14.27 
14.36 
14-45 
14.55 
14.64 

14-73 
14.82 



Per 
Cent 
by Vol- 
ume 



13-52 
13.62 

13-71 
13.81 
13.90 

13-99 

14.09 

14.1 

14.27 

14-37 

14.46 
14.56 
14-65 
14-74 
14.84 

14-93 
15.02 

15- 
15.21 

15-30 

15-40 
15-49 
15-5 
15.6 

15-77 
15.86 
15.96 
16.05 
16.15 
16.24 

16.33 

16.43 

16.52 

16.61 

16.70 

16.80 

16. 

16.98 

17.08 

17.17 

17.26 

17-37 
17-48 

17-59 
17.70 
17.81 
17.92 
18.03 
18.14 
18.25 



Grams 
per 



10.73 
10.81 
10.89 
10.95 
11.03 
11.11 
11.18 
11.26 

11-33 
11.41 

11.48 
11.56 
11.64 
11.70 
11.78 
11.85 
11.92 
12.00 
12.08 
12.14 



2.30 

2-37 
2.44 

2-51 
2-59 
2.66 

2-74 



12.96 

13-03 
13.10 
13.18 
13.26 

13-40 
13-48 
13-56 
13-63 

13-71 
13-79 
13.88 
13.96 
14.04 

14-13 
14.23 

14-32 
14-39 
14.48 



Spec. 
Grav. 

at 
iS.6°C 



-9779 
8 

7 
6 

5 
4 



0.9769 



0-9759 
8 

7 
6 

5 
4 
3 



0.9749 
8 

7 
6 

5 
4 



0.9739 
8 

7 
6 

5 
4 
3 



Absolute Alcohol. 



Per 
Cent 

by 
Weight 



14.91 

15.00 
15.08 
15-17 
15-25 
15-33 
15-42 
15-50 
15-58 
15-67 

15-75 
15-83 
15-92 
16.00 
16.08 
16.15 
16.23 
16.31 
16.38 
16.46 

16.54 
16.62 
16.69 
16.77 
16.85 
16.92 

i\7 . 00 

17- 
17.17 

17-25 

17.33 
17.42 

17-50 
17-58 
17.67 

17-75 
17-83 
17.92 
18.00 



18.15 
18.23 
18.31 
18.38 
18.46 

18.54 
18.62 
18.69 
18.77 
18.85 



Per 

Cent 
by Vol- 
ume. 



18.36 

18.48 
18.58 
18.68 
18.78 
18.88 
18.98 
19.08 
19.18 
19.28 

19-39 
19.49 

19-59 
19.68 
19.78 
19.87 
19.96 
20.06 
20.15 
20.24 

20.33 

20.43 

20.52 

20.61 

20.71 

20.80 

20. 

20.99 

21.09 

21.19 

21.29 
21.39 
21.49 

21-59 

21.69 

21.79 

21. 

21.99 

22.09 

22.18 

22.27 
22.36 
22.46 

22-55 

22.64 

22.73 

22.82 
22.92 

23-01 

21.10 



Grams 
per 



/1LCOHOLIC BEVERAGES. 663 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Con/inu€(i). 





Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 






Spec. 








Spec. 






Grav. 
at 


Per 
Cent 


(!ent Grams 


Grav. 
at 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 
at 


Per 
Cent 


Per 
Cent 


Grams 


15.6° C. 


by 


by Vol- J^' 


15.6° C. 


by 


by Vol- 


per 


15-6° C. 


by 


by Vol- 


per 




Weight 


ume. '°°''''- 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 


0.9729 


18.92 


23.19 18.41 


0.9679 


22.92 


27-95 


22.18 


0.9629 


26.60 


32-27 


25.61 


8 


19.00 


23.18 18.48 


8 


23.00 


28.04 


22.26 


8 


26.67 


32-34 


25-67 


7 


19.08 


23-38 18.56 


7 


23-08 


28.13 


22.33 


7 


26.73 


32-42 


25-73 


6 


19.17 


23-48 18-65 


6 


23-15 


28.22 


22.40 


6 


26.80 


32-50 


25-79 


5 


19-25 


23-58 18.73 


5 


23-23 


28.31 


22.47 


5 


26.87 


32-58 


25-85 


4 


19-33 


23.68 18.80 


4 


23-31 


28.41 


22.54 


4 


26.93 


32-65 


25-91 


3 


19.42 


23.78 1S.88 


3 


23-38 


28.50 


22.61 


3 


27.00 


32-73 


25-98 


2 


19-50 


23-88 18.95 


2 


23.46 


28.59 


22.69 


2 


27-07 


32.81 


26.04 


I 


19-58 


23.98 19.03 


I 


23-54 


28. 68 


22.76 


I 


27-14 


32.90 


26.10 





19.67 


24.08 19.12 





23.62 


28-77 


22-83 





27.21 


32.98 


26.17 


0.9719 


19-75 


24.18 19.19 


0.9669 


23.69 


28.86 


22-90 


0-9619 


27.29 


33-06 


26.25 


8 


19-83 


24-28 19.27 


8 


23-77 


28.95 


22.97 


8 


27-36 


33-15 


26.31 


7 


19.92 


24-38 19-36 


7 


23-85 


29.04 


23-05 


7 


27-43 


33-23 


26.37 


6 


20.00 


24.48 19.44 


6 


23.92 


29-13 


23.11 


6 


27.50 


3i-2>-^ 


26.43 


5 


20.08 


24-58 


19-51 


5 


24.00 


29.22 


23-19 


5 


27-57 


33-39 


26.51 


4 


20.17 


24.68 


19-59 


4 


24.08 


29-31 


23-27 


4 


27.64 


33-48 


26.57 


3 


20.25 


24-78 


19.66 


3 


24-15 


29.40 


23,-33 


3 


27.71 


33-56 


26.64 


2 


20.33 


24.88 


19-74 


2 


24-23 


29-49 


23.40 


2 


27-79 


33-64 


26.71 


I 


20.42 


24-98 


19.83 


I 


24-31 


29-58 


23-48 


I 


27.86 


33-73 


26.78 





20.50 


25-07 


19.90 





24-38 


29-67 


23-55 





27-93 


33-81 


26.84 


0.9709 


20.58 


25-17 


19.98 


0.9659 


24-46 


29.76 


23-62 


0.9609 


28.00 


33.89 26.90 


8 


20.67 


25-27 


20.07 


8 


24-54 


29.86 


23-70 


8 


28.06 


33.97 26.96 


7 


20.75 


25-37 


20.14 


7 


24.62 


29-95 


23-77 


7 


28.12 


34-04 27.01 


6 


20.83 


25-47 


20.22 


6 


24-69 


30.04 


23.84 


6 


28.19 


34-111 27.07 


5 


20.92 


25-57 


20.30 


5 


24-77 


30-13 


23-91 


5 


28.25 


34- 18 


27-13 


4 


21-00 


25-67 


20.33 


4 


24-85 


30.22 


23-99 


4 


28.31 


34-25 


27.18 


3 


21.08 


25-76 


20.46 


3 


24-92 


30-31 


24-05 


3 


28.37 


34-33 


27.24 


2 


21.15 


25.86 


20.52 


2 


25-00 


30.40 


24.12 


2 


28.44 


34-40 


27-31 


1 


21.23 


25-95 


20.59 


I 


25-07 


30.48 


24.19 


I 


28.50 


34-47 


27-36 





21.31 


26.04 


20.67 





25.14 


30.57 


24.26 





28.56 


34-54 


27-42 


0.9699 


21.38 


26.13 


20.73 


0.9649 


25.21 


30-65 


24-32 


0-9599 


28.62 


34-61 


27-47 


8 


21.46 


26.22 


20.81 


8 


25.79 


30-73 


24-39 


8 


28.69 


34-69 


27-53 


7 


21.54 


26.31 


20.89 


7 


25-36 


30.82 


24-46 


7 


28. 7^ 


34-76 


27-59 


6 


21.62 


26.40 


20.96 


6 


25-43 


30-90 


24-53 


6 


28.81 


34-83 


27.64 


5 


21.69 


26.49 


21.03 


5 


25-50 


30.98 


24-59 


5 


28.87 


34-90 


27-70 


4 


21.77 


26.58 


21. II 


4 


25-57 


31-07 


24.66 


4 


28.94 


34-97 


27-76 


3 


21.85 


26.67 


21.18 


3 


25.64 


2>^-'^3 


24-72 


3 


29.00 


35-05 


27.82 


2 


21.92 


26.77 


21-25 


2 


25-71 


31-23 


24-79 


2 


29.07 


35-12 


27.89 


I 


22.00 


26.86 


21-33 


I 


25-79 


31-32 


24.86 


I 


29-13 


35-20 


27-95 





22.08 


26.95 


21.40 





25.86 


31-40 


24-93 





29.20 


35-28 


28.00 


0.9689 


22.15 


27.04 


21.47 


0.9639 


25-93 


31-48 


24-99 


0-9589 


29-27 


35-35 


28.07 


8 


22.23 


27-13 


21.54 


8 


26.00 


31-57 


25.06 


8 


29-33 


35-43 


28.12 


7 


22.31 


27.22 


21-61 


7 


26.07 


31-65 


25.12 


7 


29.40 


35-51 


28.18 


6 


22.38 


27-31 


21.68 


6 


26.13 


31.72 


25.18 


6 


29-47 


35-58 


28.24 


5 


22.46 


27.40 


21.76 


5 


26.20 


31.80 


25-23 


5 


29-53 


35-66 


28.30 


4 


22.54 


27-49 


21.83 


4 


26-27 


31.88 


25-30 


4 


29.60 


35-74 


28.36 


3 


22.62 


27-59 


21.90 


3 


26.33 


31.96 


25-36 


3 


29.67 


35-81 


28.43 


2 


22.69 


27-68 


21.96 


2 


26.40 


32-03 


25-43 


2 


29-73 


35-89 


28.48 


I 


22.77 


27-77 


22.01 


I 


26.47 


32.11 


25-49 


I 


29.80 


35-97 


28.54 





22.85 


27.86 


22.12 





26.53 


32.19 


25-55 





29.87 


36.04 


28.61 



664 



POOD INSPECTION AND ANALYSIS. 



SPECIFIC GRAVITY AND PERCENTAGE OF A-'LCOUO'L— {Continued). 



Spec. 
Grav. 

at 
iS.6°C 



0.9579 
8 

7 
6 

5 
4 
3 



0.9569 

8 

7 
6 

5 
4 
3 



0.9559 
8 

7 
6 

5 
4 
3 



0.^549 
8 

7 
6 

5 
4 



C.9539 
8 

7 
6 

5 
4 
3 



Absolute Alcoliol. 



Per 

Cent 

by 

Weight 



29-93 
30.00 

30. 
30.11 

30-17 

30 • 
30.28 

30-39 
30.44 

30-50 
30-56 
30.61 
30.67 

30-7 
30.78 
30.83 
30.89 

30-94 
31.00 

31.06 

31.12 

31-19 

31-25 

31-3 

31-37 

31-44 

31-50 

31-56 

31.62 

31.69 

31-75 

31- 

31-87 

31-94 

32.00 

32.06 

32- 
32.19 

32-25 

32-31 
32-37 
32-44 
32-50 
32-56 
32.62 
32.69 

32-75 
32.81 
32-87 



Per 

Cent 

by Vol 

ume. 



36. 

36.20 

36.26 

36-32 

36- 

36-45 

36.5 

36-57 

36.64 

36.70 

36.76 

36.83 
36.89 

36-95 

37.02 

37.08 

37-14 

37- 

37-27 

37-34 

37-41 
37-48 

37-55 
37.62 

37-69 
37-76 
37-83 
37-90 
37-97 
38.04 

38. 
38.18 

38-25 

38-33 

38.40 

38-4 

38-53 

38.60 

38.68 

38.75 

38.82 
38.89 
38-96 
39-04 
39-11 
39.18 

39-25 
39-32 
39-40 
39-47 



Grams 

per 
100 cc. 



28.67 
28.73 
28.78 
28.82 
28.88 
28.92 
28.98 
29.03 
29.08 
29-13 

29.18 
29.23 
29-27 
29-33 
29.38 

29-43 
29.48 

29-53 
29-58 
29.63 

29.69 
29-74 
29.81 
29-86 
29.91 
29.97 
30-03 
30.09 

30-14 
30.20 

30. 26 

30-31 
30-36 
30.42 
30.48 
30.53 
30-59 
30-64 
30.71 

30-77 

30.81 
30.87 
30-93 
30-99 
31-05 
31.10 

31-15 
31.20 
31.26 
31-32 



Spec. 
Grav. 

at 
15.6° C. 



0.9529 
8 

7 
6 

5 
4 
3 
2 
I 
o 

0.9519 

8 

7 
6 

5 
4 
3 
2 
I 
o 

0.9509 
8 

7 
6 

5 
4 
3 
2 
I 
o 

0.9499 
8 

7 
6 

5 
4 

3 
2 

I 
o 

0.9489 
8 

7 
6 

5 
4 
3 



Absolute Alcohol. 



Per 
Cent 

by 
Weight 



32-94 
33-00 
33-06 
33-12 
33-18 
33-24 
33-29 
33-35 
33-41 
33-47 

33-53 
33-59 
33-65 
33-71 
33-76 
33-82 
33-88 
33-94 
34.00 

34-05 

34-10 
34-14 
34-19 
34-24 
34-29 
34-33 
34-38 
34-43 
34-48 
34-52 

34.57 
34.62 

34-67 
34-71 
34-76 
34.81 
34.86 
34-90 
34-95 
35-00 

35-05 
35-10 

35-15 
35-20 
35-25 
35-30 
35-35 
35-40, 
35-45 
35-50 



Per 
Cent 
by Vol- 
ume. 



39-54 
39.61 
39.68 

39-74 
39.81 

39-87 
39-94 
40.01 
40.07 
40.14 

40.20 
40.27 
40.34 
40.40 
40.47 
40-53 
40.60 
40.67 
40.74 
40.79 

.40.84 
40.90 

40-95 
41 .00 

41-05 

41. II 

41.16 

41. 

41.26 

41-32 

41-37 
41.42 
41.48 

41-53 
41.58 

41-63 
41.69 

41-74 
41.79 
41.84 



Grams 
per 



.90 

-95 
.01 
.06 
.12 
-17 
-23 
.29 

-34 
.40 



31-38 


31-43 
31-48 


31-53 


31-59 
31-63 
31.69 


31-74 
31.80 
31.86 


31-91 
31.96 


32.01 


32.07 


32.12 


32.17 


32-22 


32-27 


32-32 


32-37 


32.41 


32-45 


32-49 


32.54 


32-59 
32.63 

32.67 


32-71 


32-75 


32-79 


32-84 
32.88 


32-92 
32.96 


33- 00 


33-04 


33-09 


3i-''?> 


33-17 


33-21 


32.26 


33-30 


33-34 


33-39 


33-43 
33-48 


33-53 


33-57 
33-6i 
33-65 



Spec. 
Grav. 

at 
15.6° C 



0.9479 
8 

7 
6 

5 
4 
3 



0.9469 
8 

7 
6 

5 
4 
3 



■9459 
8 

7 
6 

5 
4 



0.9449 
8 

7 
6 

5 
4 



0.9439 
8 

7 
6 

5 
4 
3 



Absolute Alcohol. 



Per 
Cent 

by 
Weight 



35-55 
35 -60 
35-65 
35-70 
35-75 
35-80 
35-85 
35-90 
35-95 
36.00 

36.06 
36.11 

36.17 

36.22 

36.28 

36.33 

36.39 

36.44 

36-5 

36-56 

36.61 
36-67 
36.72 
36-78 
36.83 
36.89 
36.94 
37-00 
37.06 

37- 

37- 

37- 

37- 

37-33 

37-39 

37-44 

37-50 

37-56 

37.61 

37-67 

37-73 
37-78 
37-83 
37-89 
37-49 
38.00 
38.06 
38.11 
38-17 



Per 
Cent 
by Vol- 
ume 



42.45 
42-51 
42.56 
42.62 
42.67 

42-73 

42.78 

42-84 
42.89 

42-95 

43.01 

43-07 

43-13 

43-19 

43-26 

43-3 

43-38 

43-44 

43-50 

43-56 

43-63 
43-69 
43-75 
43-81 
43-87 
43-93 
44.00 
44.06 
44.12 
44.18 

44.24 
44-30 
44-36 
44-43 
44-49 
44-55 
44.61 
44.67 
44-73 
44-79 

44.86 
44-92 
44-98 
45-04 
45-10 
45.16 

45-22 

45.28 

45-34 
45-41 



ALCOHOLIC BEVERAGES. 665 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Conimwei). 



Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 




Absolute Alcohol. 














Spec. 






Grav. 

at 

15.6° c. 


Per 

Cent 


Per 

Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 
Cent 


Per 

Cent 


Grams 


Grav. 

at 


Per 

Cent 


Per 

Cent 


Grams 


bv 


by Vol- 


per 


by 


by Vol- 


per 


15.6° C. 


by 


by Vol- 


per 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 


0.9429 


38.28 


45.47 


36.08 


0-9379 


40-85 


48.26 


38.31 


0.9329 


43-29 


50-87 


40.38 


8 


38-33 


45.53 


36.13 


8 


40.90 


48.32 


38.35 


8 


43 


2,3, 


50.92 


40.42 


7 


38.39 


45.59 


36-18 


7 


40-95 


48. .3 7 


38.39 


7 


43 


39 


50-97 


40.46 


6 


38.44 


45-65 


36-23 


6 


41.00 


48-43 


38-44 


6 


43 


43 


51.02 


40-50 


5 


38.50 


45-71 


36.28 


5 


41.05 


48.48 


38-48 


5 


43 


48 


51-07 


40-54 


4 


38.56 


45-77 


36-33 


4 


41.10 


48-54 


38-52 


4 


43 


52 


51.12 


40-58 


3 


38.61 


45-83 


36-38 


3 


41-15 


48.59 


38-58 


3 


43 


57 


51-17 


40.62 


2 


38.67 


45-89 


36.43 


2 


41.20 


48.64 


38-62 


.2 


43 


62 


51.22 


40.66 


I 


38.72 


45-95 


36-48 


I 


41-25 


48-70 


38.66 


I 


43 


67 


51.27 


40.70 





38.78 


46.02 


36-53 





41-30 


48-75 


38-70 





43 


71 


51.32 


40-74 


0.9419 


38-83 


46.08 


36-57 


0.9369 


41-35 


48.80 


38-74 


0.9319 


43 


76 


51-38 


40.78 


8 


38.89 


46.14 


36.62 


8 


41.40 


48.86 


38-78 


8 


43 


81 


51-43 


40.81 


7 


38.94 


46.20 


36-67 


7 


41-45 


48.91 


38-82 


7 


43 


86 


51.48 


40.85 


6 


39.00 


46.26 


36-72 


6 


41-50 


48.97 


38-87 


6 


43 


90 


51-53 


40.89 


5 


39-05 


46.32 


36-76 


5 


41-55 


49.02 


38.91 


5 


43 


95 


51-58 


40-93 


4 


39.10 


46.37 


36-80 


4 


41.60 


49-07 


38-95 


4 


44 


00 


51-63 


40-97 


3 


39-15 


46.42 


36-85 


3 


41-65 


49-13 


38.99 


3 


44 


05 


51.68 


41.01 


2 


39.20 


46.48 


36-89 


2 


41.70 


49.18 


39-04 


2 


44 


09 


51-72 


41-05 


I 


39-25 


46.53 


36-94 


I 


41-75 


49.23 


39.08 


I 


44 


14 


51-77 


41.09 





39-30 


46.59 


36-98 





41.80 


49.29 


39-13 





44 


18 


51.82 


41 13 


9409 


39-35 


46.64 


37.02 


0.9359 


41.85 


49-34 


39-17 


0.9309 


44 


23 


51-87 


41-17 


8 


39-40 


46.70 


37-07 


8 


41.90 


49.40 


39-21 


8 


44 


27 


51-91 


41.20 


7 


39-45 


46-75 


37-11 


7 


41-95 


49-45 


39-25 


7 


44 


32 


51.96 


41.24 


6 


39-50 


46.80 


37-15 


6 


42.00 


49 50 


39-30 


6 


44 


36 


52-01 


41.28 


5 


39-55 


46.86 


37-19 


5 


42.05 


49-55 


39-34 


5 


44 


41 


52-06 


41-31 


4 


39.60 


46.91 


37.23 


4 


42.10 


49.61 


39-38 


4 


44 


46 


52.10 


41-35 


3 


39-65 


46.97 


37-27 


3 


42.14 


49.66 


39-42 


3 


44 


50 


52-15 


41.49 


2 


39-70 


47-02 


37-32 


2 


42-19 


49.71 


39-46 


2 


44 


55 


52.20 


41-43 


I 


39-75 


47-08 


37-36 


I 


42.24 


49.76 


39-50 


I 


44 


59 


52-25 


41.47 





39.80 


47-13 


37-41 





42.29 


49.81 


39-54 





44 


64 


52-29 


41-51 


0.9399 


39-85 


47-18 


37-45 


0.9349 


42.33 


49.86 


39-58 


0.9299 


44 


68 


52-34 


41-55 


8 


39-90 


47-24 


37-49 


8 


42.38 


49.91 


39.62 


8 


44 


73 


52-39 


41-59 


7 


39-95 


47.29 


37-53 


7 


42.43 


49.96 


39.66 


7 


44 


77 


52-44 


41-63 


6 


40.00 


47-35 


37-58 


6 


42.48 


50.01 


39-70 


6 


44 


82 


52.48 


41.67 


5 


40.05 


47.40 


37.62 


5 


42.52 


50.06 


39-74 


5 


44 


86 


52.53 


41.70 


4 


40.10 


47-45 


37-67 


4 


42-57 


50.11 


39-78 


4 


44 


91 


52.58 


41-74 


3 


40.15 


47-51 


37-71 


3 


42.62 


50.16 


39-82 


3 


44 


96 


52.63 


41-77 


2 


40.20 


47-56 


37-75 


2 


42.67 


50.21 


39.86 


2 


45 


00 


52.68 


41.81 


I 


40.25 


47.62 


37.80 


I 


42.71 


50.26 


39-90 


1 


45 


05 


52.72 


41.85 





40-30 


47.67 


37-84 





42.76 


50-31 


39-94 





45 


09 


52-77 


41.89 


0-9389 


40.35 


47.72 


37-88 


0.9339 


42. Si 


50-37 


39-98 


0.9289 


45 


14 


52.82 


41-93 


8 


40.40 


47-78 


37-92 


8 


42.86 


50-42 


40.02 


8 


45 


18 


52-87 


41.97 


7 


40-45 


47-83 


37-96 


7 


42-90 


50-47 


40.06 


7 


45 


23 


52-91 


42.00 


6 


40.50 


47.89 


38.00 


6 


42.95 


50-52 


40.10 


6 


45 


27 


52-96 


42.04 


5 


40-55 


47-94 


38-05 


5 


43-00 


50-57 


40.14 


5 


45 


32 


53-OI 


42.08 


4 


40.60 


47-99 


38.09 


4 


43-05 


50.62 


40- 18 


4 


45 


36 


53-06 


42.12 


3 


40-65 


48.05 


38-13 


3 


43-IO 


50-67 


40.22 


3 


45 


41 


53-10 


42.16 


2 


40.70 


48.10 


38.18 


2 


43-13 


50-72 


40.26 


2 


45 


46 


53-15 


42.19 


1 


40.75 


48.16 


38-22 


I 


43-19 


50-77 


40.30 


I 


45 


50 


53-20 


42.23 





40.80 


48.21 


38.27 





43-24 


50.82 


40.34 





45-55 


53-24 


42.27 



666 FOOD INSPECTION AND ANALYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Cow/mMei). 



Spec. 

Grav. 

at 


Absolute Alcohdl. 


Spec. 
Grav. 

at 


Absolute Alcohol. 


Spec. 
Grav. 

at 


Absolute Alcohol. 


Per 


Per 


Per 


Per 


Per 


Per 


^ c fi9 C 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15. U V-*. 


by 


by Vol- 


by 


by Vol- 




^.^y, 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.9279 


45-59 


53-29 


0.9229 


47-86 


55-65 


0.9179 


50.13 


57-97 


8 


45-64 


53-34 


8 


47-91 


55-69 


8 


50-17 


58.01 


7 


45-68 


53-39 


7 


47.96 


55-74 


7 


50.22 


58.06 


6 


45-73 


53-43 


6 


48.00 


55-79 


6 


50.26 


58.10 


5 


45-77 


53-48 


5 


48.05 


55-83 


5 


50.30 


58.14 


4 


45-82 


53-53 


4 


48.09 


55-88 


4 


50-35 


58.19 


3 


45-86 


53-58 


3 


48.14 


55-93 


3 


50.39 


58.23 


2 


45-91 


53-62 


2 


48.18 


55-97 


2 


50.43 


58.28 


I 


45-96 


53-67 


r 


48.23 


56-02 


I 


50-48 


58-32 





46.00 


53-72 





48.27 


56.07 





50-52 


58-36 


0.9269 


46.05 


53-77 


0.9219 


48.32 


56.11 


0.9169 


50-57 


58-41 


8 


46.09 


53-81 


8 


48.36 


56.16 


8 


50-61 


58.45 


7 


46.14 


53-86 


7 


48.41 


56.21 


7 


50-65 


58.50 


6 


46.18 


53-91 


6 


48.46 


56.25 


6 


50.70 


58.54 


5 


46.23 


53-&5 


5 


48.50 


56.30 


5 


50.74 


58.58 


4 


46.27 


54.00 


4 


48.55 


56.35 


4 


50.78 


58.63 


3 


46.32 


54-05 


3 


48.59 


56-40 


3 


50-83 


58.67 


2 


46.36 


54.10 


2 


48.64 


56.44 


2 


50-87 


58.72 


I 


46.41 


54-14 


I 


48.68 


56.49 


I 


50-91 


58.76 





46.46 


54.19 





48.73 


56.54 





50.96 


58-80 


0.9259 


46.50 


54.24 


0.9209 


48.77 


56.58 


0.9159 


51.00 


58-85 


8 


46.55 


54.29 


8 


48.82 


56.63 


8 


51-04 


58.89 


7 


46.59 


54.33 


7 


48.86 


56.68 


7 


51.08 


58-93 


6 


46.64 


54-38 


6 


48.91 


56.72 


6 


51-13 


58-97 


5 


46.68 


54.43 


5 


48.96 


56-77 


5 


51-17 


59-01 


4 


46.73 


54-47 


4 


49.00 


56.82 


4 


51.21 


59-05 


3 


46.77 


54.52 


3 


49-04 


56.86 


3 


51-25 


59-09 


2 


46.82 


54-57 


2 


49.08 


56.90 


2 


51-29 


59-14 


I 


46.86 


54.62 


I 


49-12 


56-94 


I 


51-33 


59-18 





46.91 


54.66 





49.16 


56.98 





51-38 


59.22 


0.9249 


46.96 


54.71 


0.9199 


49-20 


57.02 


0.9149 


51-42 


59-26 


8 


47.00 


54.76 


Proof 8 


49-24 


57-06 


8 


51.46 


59-30 


7 


47.05 


54.80 


7 


49.29 


57-10 


7 


51-50 


59-34 


6 


47.09 


54-85 


6 


49-34 


57-15 


6 


51-54 


59-39 


5 


47-14 


54-90 


5 


49-39 


57.20 


5 


51-58 


59-43 


4 


47-18 


54.95 


4 


49-44 


57-25 


4 


51-63 


59-47 


3 


47-23 


54.99 


3 


49-49 


57-30 


3 


51-67 


59-51 


2 


47.27 


55-04 


2 


49-54 


57-35 


2 


51-71 


59-55 


I 


47-32 


55-09 


I 


49-59 


57-40 


I 


51-75 


59-59 





47-36 


55-13 





49-64 


57-45 





51-79 


59-63 


0.9239 


47-41 


55-18 


0.9189 


49.68 


57-49 


0.9139 


51-83 


59.68 


8 


47-46 


55-23 


8 


49-73 


57-54 


8 


51.88 


59-72 


7 
6 


47-50 


55-27 


7 


49-77 


57-59 


7 


51.92 


59-76 


47-55 


55-32 


6 


49-82 


57-64 


6 


51.96 


59.80 


5 


47-59 


55-37 


5 


49.86 


57-69 


5 


52.00 


59-84 


4 


47-64 


55-41 


4 


49-91 


57-74 


4 


52-05 


59-89 


3 


47.68 


55-46 


3 


49-95 


57-79 


3 


52.09 


59-93 


2 


47-73 


55-5t 


2 


50.00 


57-84 


2 


52.14 


59.98 


I 


47-77 


55-55 


I 


50.04 


57-88 


I 


52.18 


60.02 





47-82 


55-60 





50.09 


58.92 





52.23 


60.07 



/1LCOHOUC BE ys RAGES. 



667 



SPECIFIC GRAVITY AND PERCENTAGE OF W.COU.O'L— {Continued). 



. 


Absolute Alcohol. 




Absolute Alcohol. 




Absolute AlcohoL 


Spec. ' 






Spec. 






Spec. 






Grav. 


Per 


Per 


Grav. 


Per 


Per 


Grav, 


Per 


Per 


at 
15.6° C. I 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.9«iL29 


52.27 


60.12 


0.9079 


54-52 


62.36 


0.9029 


56.82 


64.63 


8 


52-32 


60.16 


8 


54-57 


62.41 


8 


56.86 


64.67 


7 


52.36 


60.21 


7 


54-62 


62.45 


7 


56.91 


64.71 


6 


52-41 


60.25 


6 


54-67 


62.50 


6 


56-95 


64.76 


5 


52-45 


60.30 


5 


54-71 


62.55 


5 


57.00 


64.80 


4 


52-50 


60.34 


4 


54.76 


62.60 


4 


57-04 


64-85 


3 


52-55 


60.39 


3 


54-81 


62.65 


3 


57-08 


64.89 


2 


52-59 


60.44 


2 


54-86 


62.69 


2 


57-13 


64-93 


I 


52.64 


60.47 


I 


54-90 


62.74 


I 


57-17 


64-97 





52-68 


60.52 





54.95 


62.79 





57-21 


65.01 


0.9119 


52-73 


60.56 


0.9069 


55-00 


62.84 


0.9019 


57-25 


65-05 


8 


52.77 


60.61 


8 


55-05 


62.88 


8 


57-29 


65-09 


7 


52-82 


60.65 


7 


55-09 


62.93 


7 


57-33 


65-13 


6 


52.86 


60.70 


6 


55-14 


62.97 


6 


57-38 


65-17 


5 


52-91 


60.74 


5 


55-18 


63.02 


5 


57-42 


65-21 


4 


52-95 


60.79 


4 


55-23 


63-06 


4 


57-46 


65-25 


3 


53.00 


60.85 


3 


55-27 


63.11 


3 


57-50 


65.29 


2 


53-04 


60.89 


2 


55.32 


63-15 


2 


57.54 


65.33 


I 


53-09 


60-93 


I 


55-36 


63-20 


I 


57-58 


65-37 





53-13 


60.97 





55-41 


63.24 





57-63 


65.41 


0.9109 


53-17 


61.02 


0.9059 


55-45 


63.28 


0.9009 


57-67 


65-45 


8 


53-22 


61.06 


8 


55-50 


63-33 


8 


57-71 


65-49 


7 


53-26 


61.10 


7 


55-55 


63-37 


7 


57-75 


65-53 


6 


53-30 


61.15 


6 


55-59 


63.42 


6 


57-79 


65-57 


5 


53-35 


61.19 


5 


55-64 


63-46 


5 


57-83 


65.61 


4 


53-39 


61.23 


4 


55-68 


63-51 


4 


57-88 


65-65 


3 


53-43 


61.28 


3 


55-73 


63-55 


3 


57-92 


65.69 


2 


53-48 


61.32 


2 


55-77 


63.60 


2 


57-96 


65.73 


I 


53-52 


61.36 


I 


55-82 


63.64 


I 


sS.oo 


65-77 





53.57 


61.40 





55-86 


63-69 





58.05 


65.81 


0.9099 


53-61 


61.45 


0.9049 


55-91 


63-73 


0.8999 


58.09 


65-85 


8 


53-65 


61.49 


8 


55-95 


63-78 


8 


58.14 


65.90 


7 


53-70 


6r-53 


7 


56.00 


63-82 


7 


58.18 


65.94 


6 


53-74 


61-58 


6 


56-05 


63-87 


6 


58.23 


65-99 


5 


53-78 


61.62 


5 


56-09 


63.91 


5 


58-27 


66.03 


4 


53-83 


61.66 


4 


56-14 


63-96 


4 


58-32 


66.07 


3 


53-87 


61.71 


3 


56-18 


64.00 


3 


58-36 


66.12 


2 


53-91 


61-75 


2 


56.23 


64.05 


2 


58-41 


66.16 


I 


53-96 


61.79 


I 


56-27 


64.09 


I 


58-45 


66.21 





54-00 


61.84 





56-32 


64.14 





58-50 


66.25 


0.9089 


54-05 


61.88 


0.9039 


56.36 


64.18 


0.8989 


58-55 


66.29 


8 


54-10 


61.93 


8 


56.41 


64.22 


8 


58-59 


66.34 


7 


54-14 


61.98 


7 


56.45 


64-27 


7 


58.64 


66.38 


6 


54-19 


62.03 


6 


56-30 


64.31 


6 


58.68 


66.43 


5 


54-24 


62.07 


5 


56-55 


64.36 


5 


58-73 


66.47 


4 


54-29 


62.12 


4 


56.59 


64.40 


4 


58-77 


66.51 


3 


54-33 


62.17 


3 


56.64 


64-45 


3 


^lil 


66.56 


2 

I 


54-38 
54-43 


62.22 
62.26 


2 

I 


56.68 
56.73 


64-49 
64-54 


2 

I 


58.86 
58-91 


66.60 
66.65 





54.48 


62.31 





56-77 


64-58 





58-95 


66.69 



668 FOOD INSPECTION AND AN/i LYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF k-LCOUOl.— {Continued). 





Absolute Alcohol. 


Spec. 


Absolute 


Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 














Grav. 


Per 


Per 


Grav. 
at 


Per 


Per 


Grav. 

at 


Per 


Per 


at 
iS.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8979 


59.00 


66.74 


0.8929 


61.13 


68.76 


0.8879 


63-30 


70.81 


8 


59-04 


66.78 


8 


61.17 


68.80 


8 


63-35 


70-85 


7 


59-09 


66.82 


7 


61.21 


68.83 


7 


63-39 


70.89 


6 


59-13 


66.86 


6 


61.25 


68.87 


6 


63-43 


70=93 


5 


59-17 


66.90 


5 


61.29 


68.91 


5 


63.48 


70-97 


4 


59.22 


66.94 


4 


61-33 


68.95 


4 


63-52 


71.01 


3 


59.26 


66.99 


3 


61.38 


68.99 


3 


63-57 


71-05 


2 


59-30 


67-03 


2 


61.42 


69.03 


2 


63.61 


71.09 


I 


59-35 


67-07 


I 


61.46 


69.07 


I 


63-65 


71-13 





59-39 


67.11 





61.50 


69.11 





63-70 


71.17 


0.8969 


59-43 


67-15 


0.8919 


61.54 


69.15 


0.8869 


63-74 


71.22 


8 


59-48 


67.19 


8 


61.58 


69.19 


8 


63.78 


71.26 


7 


59-52 


67.24 


7 


61.63 


69.22 


7 


63-83 


71-30 


6 


59-57 


67.28 


6 


61.67 


69.26 


6 


63.87 


71-34 


5 


59-61 


67.32 


5 


61.71 


69-30 


5 


63.91 


71-38 


4 


59-65 


67.36 


4 


61-75 


69-34 


4 


63.96 


71-42 


3 


59-70 


67.40 


3 


61.79 


69.38 


3 


64.00 


71.46 


2 


59-74 


67.44 


2 


61.83 


69.42 


2 


64.04 


71-50 


I 


59-78 


67.49 


I 


61.88 


69.46 


I 


64.09 


71-54 





59-83 


67-53 





61.92 


69.50 





64.13 


71-58 


0.8959 


59-87 


67-57 


0.8909 


61.96 


69-54 


0.8859 


64.17 


71.62 


8 


59-91 


67.61 


8 


62.00 


69.58 


8 


64.22 


71-66 


7 


59-96 


67-65 


7 


62.05 


69.62 


7 


64.26 


71.70 


6 


60.00 


67.69 


6 


62.09 


69.66 


6 


64-30 


71-74 


5 


60.04 


67-73 


5 


62.14 


69.71 


5 


64-35 


71.78 


4 


60.08 


67-77 


4 


62.18 


69-75 


4 


64-39 


71.82 


3 


60.13 


67.81 


3 


62.23 


69.79 


3 


64-43 


71.86 


2 


60.17 


67.85 


2 


62.27 


69.84 


2 


64.48 


71.90 


I 


60.21 


67.89 


I 


62.32 


69.88 


I 


64.52 


71.94 





60.26 


67-93 





62.36 


69.92 





64-57 


71.98 


0.8040 


60.29 


67-97 


0.8899 


62.41 


69.96 


0.8849 


64.61 


72.02 


8 


60.33 


68.01 


8 


62.45 


70.01 


8 


64-65 


72.06 


7 


60.38 


68.05 


7 


62.50 


70.05 


7 


64.70 


72.10 


6 


60.42 


68.09 


6 


62.55 


70.09 


6 


64-74 


72.14 


5 


60.46 


68.13 


5 


62.59 


70.14 


5 


64.78 


72.18 


4 


60.50 


68.17 


4 


62.64 


70.18 


4 


64.83 


72.22 


3 


60.54 


68.21 


3 


62.68 


70.22 


3 


64.87 


72.26 


2 


60.58 


68.25 


2 


62.73 


70.27 


2 


64.91 


72.30 


I 


60.63 


68 29 


I 


62.77 


70-31 


I 


64.96 


72-34 





60.67 


68.33 





62.82 


70-35 





65.00 


72.38 


0.8939 


60.71 


68.36 


0.8889 


62.86 


70.40 


0.8839 


65.04 


72.42 


8 


60.76 


68.40 


8 


62.91 


70.44 


8 


65.08 


72.46 


7 


60-79 


68.44 


7 


62.95 


70.48 


7 


65-13 


72.50 


6 


60.83 


68.48 


6 


63.00 


70.52 


6 


65-17 


72-54 


5 


60.88 


68.52 


5 


63.04 


70-57 


5 


65.21 


72.58 


4 


60.92 


68.56 


4 


63.09 


70.61 


4 


65-25 


72.61 


3 


60.96 


68.60 


3 


63-13 


70.65 


3 


65-29 


72-65 


2 


61.00 


68.64 


2 


63-17 


70.69 


2 


65-33 


72.69 


I 


61.04 


68.68 


I 


63.22 


70.73 


I 


65-38 


72.73 





61.08 


68.72 





63.26 


70.77 





65-42 


72.7? 



ALCOHOLIC BEVERAGES. 669 

SPECIFIC GRAVITY AND PERCENTAGE OF KLCOHOl.— {Continued). 





Absolute Alcohol. 




Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 






Spec. 










Grav. 


Per 


Per 


Grav. 


Per 


Per 


Grav. 


Per 


Per 


at 
15.6° C. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8829 


65.46 


72.80 


0.8779 


67-58 


74-74 


0.8729 


69.67 


76.61 


8 


65-50 


72.84 


8 


67.63 


74-78 


8 


69.71 


76.65 


7 


65-54 


72.88 


7 


67.67 


74-82 


7 


69-75 


76.68 


6 


65-58 


72.92 


6 


67.71 


74.86 


6 


69.79 


76.72 


5 


65-63 


72.96 


5 


67-75 


74-89 


5 


69-83 


76.76 


4 


65.67 


72.99 


4 


67.79 


74-93 


4 


69.88 


76.80 


3 


65-71 


73-03 


3 


67.83 


74-97 


3 


69.92 


76.83 


2 


65-75 


73-07 


2 


67.88 


75-01 


2 


69.96 


76.87 


I 


65-79 


73-11 


I 


67.92 


75-04 


I 


70.00 


76.91 





65-83 


73-15 





67.96 


75.08 





70.04 


76.94 


0.8819 


65.88 


73-19 


0.8769 


68.00 


75-12 


0.8719 


70.08 


76.98 


8 


65.92 


73.22 


8 


68.04 


75-i6 


8 


70.12 


77.01 


7 


65.96 


73.26 


7 


68.08 


75-19 


7 


70. 16 


77.05 


6 


66.00 


73-30 


6 


68.13 


75-23 


6 


70.20 


77.08 


5 


66.04 


73-34 


5 


68.17 


75-27 


5 


70.24 


77.12 


4 


66.09 


73-38 


4 


68.21 


75-30 


4 


70.28 


77-15 


3 


66.13 


73-42 


3 


68.25 


75-34 


3 


70.32 


77-19 


2 


66.17 


73-46 


2 


68.29 


75-38 


2 


70.36 


77.22 


I 


66.2 2 


73-50 


I 


68.33 


75-42 


I 


70.40 


77.25 





66.26 


73-54 





68.38 


75-45 





70.44 


77.29 


0.8809 


66.30 


73-57 


0.8759 


68.42 


75-49 


0.8709 


70-48 


77.32 


8 


66-35 


73-61 


8 


68.46 


75-53 


8 


70.52 


77.36 


7 


66.39 


73-65 


7 


68.50 


75-57 


7 


70-56 


77-39 


6 


66.43 


73-69 


6 


68.54 


75.60 


6 


70.60 


77-43 


5 


66.48 


73-73 


5 


68.58 


75-64 


5 


70.64 


77-46 


4 


66.52 


73-77 


4 


68.63 


75-68 


4 


70.68 


77-50 


3 


66.57 


73-81 


3 


68.67 


75-72 { 


3 


70.72 


77-53 


2 


66.61 


73-85 


2 


68.71 


75-75 


2 


70.76 


77-57 


I 


66.65 


73-89 


I 


68.75 


75-79 


I 


70.80 


77.60 





66.70 


73-93 





68.79 


75-83 





70.84 


77-64 


0.8799 


66.74 


73-97 


0.8740 


68.83 


75-87 


0.8699 


70.88 


77.67 


8 


66.78 


74-01 


8 


68.88 


75-90 


8 


70.92 


77.71 


7 


66.83 


74-05 


7 


68.92 


75-94 


7 


70.96 


77-74 


6 


66.87 


74-09 


6 


68.96 


75-98 


6 


71.00 


77.78 


5 


66.91 


74-13 


5 


69.00 


76.01 


5 


71.04 


77.82 


4 


66.96 


74-17 


4 


69.04 


76.05 


4 


71.08 


77-85 


3 


67.00 


74.22 


3 


69.08 


76.09 


3 


71.13 


77.89 


2 


67.04 


74-25 


2 


69.13 


76-13 


2 


71.17 


77-93 


I 


67.08 


74-29 


I 


69.17 


76.16 


I 


71.21 


77.96 





67-13 


74-33 





69.21 


76.20 





71-25 


78.00 


0.8789 


67.17 


74-37 


0-8739 


69-25 


76.24 


0.8689 


71.29 


78.04 


8 


67.21 


74-40 


8 


69.29 


76.27 


8 


71-33 


78.07 


7 


67.25 


74-44 


7 


69-33 


76.31 


7 


71-38 


78.11 


6 


67.29 


74-48 


6 


69.38 


76-35 


6 


71.42 


78-14 


5 


67-33 


74-52 


5 


69.42 


76-39 


5 


71.46 


78.18 


4 


67-38 


74-55 


4 


69.46 


76.42 


4 


71-50 


78.22 


3 


67.42 


74-59 


3 


69-50 


76.46 


3 


71-54 


78-25 


2 


67.46 


74-63 


2 


69-54 


76-50 


2 


71-58 


78-29 


I 


67.50 


74-67 


I 


69-58 


76-53 


I 


71-63 


78.33 





67-54 


74-70 





69.63 


76-57 





71.67 


78.36 



670 FOOD INSPECTION /1ND y1N/i LYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF KLCO'iiO'L--{Continued). 





Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


— 






Spec. 






Spec. 






spec. 














Grav. 


Per 


Per 


Grav. 

at 


Per 


Per 


Grav. 
at 


Per 


Per 


at 
15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


by 


by Vol- 




by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8679 


71.71 


78.40 


0.8629 


73-83 


80.26 


0.8579 


76.08 


82.23 


8 


71-75 


78.44 


8 


73-88 


80.30 


8 


76 


-13 


82.26 


7 


71.79 


78.47 


7 


73-92 


80.33 


7 


76 


-17 


82.30 


6 


71-83 


78.51 


6 


73-96 


80.37 


6 


76 


21 


82-33 


5 


71.88 


78-55 


5 


74.00 


80.40 


5 


76 


25 


82.37 


4 


71.92 


78.58 


4 


74-05 


80.44 


4 


76 


29 


82.40 


3 


71.96 


78.62 


3 


74.09 


80.48 


3 


76 


a 


82.44 


2 


72.00 


78.66 


2 


74.14 


80.52 


2 


76 


38 


82.47 


I 


72.04 


78.70 


I 


74.18 


80.56 


I 


76 


42 


82.51 





72.09 


78-73 





74-23 


80.60 





76 


46 


82.54 


0.8669 


72-13 


78.77 


0.8619 


74-27 


80.64 


0.8569 


76 


50 


82.58 


8 


72.17 


78.81 


8 


74-32 


80.68 


8 


76 


54 


82.61 


7 


72.22 


78.85 


7 


74-36 


80.72 


7 


76 


58 


82.65 


6 


72.26 


78.89 


6 


74.41 


80.76 


6 


76 


63 


82.69 


S 


72.30 


78.93 


5 


74-45 


80.80 


5 


76 


67 


82.72 


4 


72-35 


78.96 


4 


74-50 


80.84 


4 


76 


71 


82.76 


3 


72-39 


79.00 


3 


74-55 


80.88 


3 


76 


75 


82.79 


2 


72-43 


79.04 


2 


74.59 


80.92 


2 


76 


79 


82.83 


I 


72.48 


79.08 


I 


74.64 


80.96 


I 


76 


83 


82.86 





72.52 


79.12 





74.68 


81.00 





76 


88 


82.90 


0.8659 


72-57 


79.16 


. 8609 


74.73 


81.04 


0-8559 


76 


92 


82.93 


8 


72.61 


79.19 


8 


74-77 


81.08 


8 


76 


96 


82.97 


7 


72.65 


79-23 


7 


74.82 


81.12 


7 


77 


00 


83-00 


6 


72.70 


79.27 


6 


74.86 


81.16 


6 


77 


04 


83.04 


5 


72-74 


79-31 


5 


74.91 


81.20 


5 


77 


08 


83.07 


4 


72.78 


79-35 


4 


74.95 


81.24 


4 


77 


13 


83.11 


3 


72.83 


79-39 


3 


75.00 


81.28 


3 


77 


17 


83.14 


2 


72.87 


79.42 


2 


75-05 


81.32 


2 


77 


21 


83.18 


I 


72.91 


79.46 


I 


75.09 


81.36 


I 


77 


25 


83.21 





72.96 


79-50 





75-14 


81.40 





77 


29 


83-25 


0.8649 


73.00 


79-54 


0.8599 


75-18 


81.44 


0.8549 


77 


33 


83.28 


8 


73-04 


79-57 


8 


75-23 


81.48 


8 


77 


38 


83.32 


7 


73.08 


79-61 


7 


75.27 


81.52 


7 


77 


42 


83.36 


6 


73-13 


79-65 


6 


75-33 


81.56 


6 


77 


46 


83-39 


5 


73-17 


79.68 


5 


75-36 


81.60 


5 


77 


50 


83-43 


4 


73-21 


79.72 


4 


75-41 


81.64 


4 


77 


54 


83.46 


3 


73-25 


79-75 


3 


75-45 


81.68 


3 


77 


58 


83-50 


2 


73-29 


79-79 


2 


75-50 


81.72 


2 


77 


63 


83-53 


I 


73-33 


79-83 


I 


75.55 


81.76 


I 


77 


67 


83-57 





73-38 


79.86 





75-59 


81.80 





77 


71 


83.60 


0.8639 


73-42 


79.90 


0.8589 


75-64 


81.84 


0.8539 


77 


75 


83.64 


8 


73-46 


79-94 


8 


75.68 


81.88 


8 


77 


79 


83.67 


7 


73-50 


79-97 


7 


75-73 


81.92 


7 


77 


83 


83-71 


6 


73-54 


80.01 


6 


75-77 


81.96 


6 


77 


88 


83-74 


5 


73-58 


80.04 


5 


75.82 


82.00 


5 


77 


92 


83.78 


4 


73-63 


80.08 


4 


75.86 


82.04 


4 


77 


96 


83.81 


3 


73-67 


80.12 


3 


75-91 


82.08 


3 


78 


00 


83-85 


2 


73-71 


80.15 


2 


75-95 


82.12 


2 


78 


04 


83.88 


1 


73-75 


80.19 


I 


76.00 


82.16 


I 


78 


08 


83.91 





73-79 


80.22 





76.04 


82.19 





78.12 


83-94 



ALCOHOLIC BEVERAGES. 671 

SPECIFIC GRAVITY AND PERCENTAGE OF KLCOB.O\.— (Continued). 



Spec. 


Absolute 


Alcohol. 


Spec. 


Absolute Alcohol. 




Absolute Alcohol. 










Spec. 






Grav. 


Per 


Per 


Grav. 


Per 


Per 


Grav. 


Per 


Per 


at 
13.6° C. 


Cent 


Cent. 


at 
15.6° C. 


Cent 


Cent 


at 
iS.6° C. 


Cent 


Cent 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8529 


78.16 


83-98 


0.8479 


80.17 


i 85.63 


0.8429 


82.19 


87.27 


8 


78.20 


84.01 


8 


80.21 


85.66 


8 


82.23 


87-30 


7 


78.24 


84.04 


7 


80.25 


1 85.70 


7 


82.27 


87-34 


6 


78.28 


84.08 


6 


80.29 


85.73 


6 


82.31 


87-37 


5 


78.32 


84.11 


5 


80.33 


85-77 


5 


82.35 


87.40 


4 


78.36 


84.14 


4 


; 80.38 


85.80 


4 


82.38 


87-43 


3 


78.40 


84.18 


3 


80.42 


85-84 


3 


82.42 


87.46 


2 


78.44 


84.21 


2 


80.46 


85-87 


2 


82.46 


87-49 


I 


78.48 


84.24 


I 


80.50 


1 85.90 ' 


! 

I 


82.50 


87-52 





78.52 


84-27 





80.54 


85.94 





82.54 


87-55 


0,8519 


78.56 


84-31 


0.8469 


80.58 


\ 85.97 


0.8419 


82.58 


87.58 


8 


78.60 


84-34 


8 


80.63 


86.01 i 


8 


82.62 


87.61 


7 


78.64 


84-37 


7 


80.67 


86.04 


7 


82.65 


87.64 


6 


78.68 


84.41 


6 


80.71 


86.08 


6 


82.69 


87-67 


5 


78.72 


84.44 


5 


80.75 


86.11 


5 


82.73 


87.70 


4 


78.76 


84-47 


4 


80.79 


86.15 


4 


82.77 


87-73 


3 


78.80 


84-51 


3 


80.83 


86.18 j 


3 


82.81 


87.76 


2 


78.84 


84.54 


2 


80.88 


86.22 


2 


82.85 


87.79 


I 


78.88 


84-57 


I 


80.92 


86.25 


I 


82.88 


87.82 





78.92 


84.60 





80.96 


86.28 





82.92 


87-85 


0.8509 


78.96 


84.64 


0.8459 


81.00 


86.32 


0.8409 


82.96 


87.88 


8 


79.00 


84.67 


. 8 


81.04 


86.35 


8 


83.00 


87.91 


7 


79.04 


84.70 


7 


81.08 


86.38 


7 


83.04 


87-94 


6 


79.08 


84-74 


6 


81.12 


86.42 


6 


83.08 


87-97 


5 


79.12 


84-77 


5 


81.16 


86.45 


5 


83.12 


88.00 


4 


79.16 


84.80 


4 


81.20 


86.48 


4 


83-15 


88.03 


3 


79.20 


84-83 


3 


81.24 


86.51 


3 


83-19 


88.06 


2 


79.24 


84.87 


2 


81.28 


86.54 


2 


83-23 


88.09 


I 


79.28 


84.90 


I 


81.32 


86.58 


I 


83-27 


88.13 





79-32 


84-93 





81.36 


86.61 





83-31 


88.16 


0.8499 


79-36 


84-97 


0.8449 


81.40 


86.64 


0.8399 


83-35 


88.19 


8 


79.40 


85.00 ; 


8 


81.44 


86.67 


8 


83-38 


88.22 


7 


79-44 


85-03 i 


7 


81.48 


86.71 


7 


83-42 


88.25 


6 


79.48 


85.06 


6 


81.52 


86.74 ' 


6 


83-46 


88.28 


5 


79-52 


85.10 


5 


81.56 


86.77 


5 


83-50 


88.31 


4 


79-56 


85-13 ' 


4 


81.60 


86.80 


4 


83-54 


88.34 


3 


79.60 


85.16 


3 


81.64 


86.83 


3 


83-58 


88.37 


2 


79-64 


85.19 


2 


81.68 


86.87 


2 


83-62 


88.40 


I 


79.68 


85-23 


I 


81.72 


86.90 


I 


83-65 


88.43 





79-72 


85.26 





81.76 


86.93 





83.69 


88.46 


0.8489 


79.76 


85.29 


0.8439 


81.80 


86.96 i 


0.8389 


83-73 


88.49 


8 


79.80 


85-33 


8 


81.84 


86.99 


8 


83-77 


88.52 


7 


79-84 


85-36 


7 


81.88 


87-03 


7 


83.81 


88.55 


6 


79.88 


85-39 


6 


81.92 


87.06 ' 


6 


83-85 


88.58 


5 


79-92 


85.42 


5 


81.96 


87.09 


5 


83.88 


88.61 


4 


79.96 


85.46 


4 


82.00 


87.12 


4 


83.92 


88.64 


3 


80.00 


85-49 


3 


82.04 


87-15 


3 


83-96 


88.67 


2 


80.04 


85-53 


2 


82.08 


87.18 


2 


84.00 


88.70 


I 


80.08 


85-56 


I 


82.12 


87.21 


I 


84.04 1 


88.73 





80.13 


85-59 

1 





82.15 


87.24 





84.08 I 


88.76 



672 FOOD INSPECTION AND ANALYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF KLCOnO'L— {Continued). 





Absolute Alcohol. 


Spec. 

Grav. 

at 


Absolute Alcohol. 


Spec. 
Grav. 

at 


Absolute Alcohol. 


Spec. 
Grav. 


Per 


Per 


Per 


Per 


Per 


Per 


at 
iS.6°C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent. 


by 


by Vol- 




by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8379 


84.12 


88.79 


0.8329 


86.08 


90-32 


0.8279 


88.00 


91.78 


8 


84.16 


88.83 


8 


86.12 


90-35 


8 


88.04 


91.81 


7 


84.20 


88.86 


7 


86.15 


90.38 


7 


88.08 


91.84 


6 


84.24 


88.89 


6 


86.19 


90.40 


6 


88.12 


91.87 


5 


84.28 


88.92 


5 


86.23 


90-43 


5 


88.16 


91.90 


4 


84.32 


88.95 


4 


86.27 


90.46 


4 


88.20 


91-93 


3 


84.36 


88.98 


3 


86.31 


90.49 


3 


88.24 


91.96 


2 


84.40 


89.01 


2 


86.35 


90.52 


2 


88.28 


91.99 


I 


84.44 


89.05 


I 


86.38 


90-55 


I 


88.32 


92.02 





84.48 


89.08 





86.42 


90-58 





88.36 


92-05 


0.8369 


84.52 


89.11 


0.8319 


86.46 


90.61 


0.8269 


88.40 


92.08 


8 


84.56 


89.14 


8 


86.50 


90.64 


8 


88.44 


92.12 


7 


84.60 


89.17 


7 


86.54 


90.67 


7 


88.48 


92.15 


6 


84.64 


89.20 


6 


86.58 


90.70 1 


6 


88.52 


92.18 


5 


84.68 


89.24 


5 


86.62 


90-73 


5 


88. =^6 


92.21 


4 


84-72 


89.27 


4 


86.65 


90.76 


4 


88.60 


92-24 


3 


84.76 


89.30 


3 


86.69 


90.79 


3 


88.64 


92.27 


2 


84.80 


89-33 


2 


86.73 


90.82 


2 


88.68 


92-30 


I 


84.84 


89.36 


I 


86.77 


90.85 


I 


88.72 


92-33 





84.88 


89-39 





86.81 


90.88 





88.76 


92.36 


0.8359 


84.92 


89.42 


0.8309 


86.85 


90.90 


0.8259 


88.80 


92-39 


8 


84.96 


89.46 


8 


86.88 


90-93 


8 


88.84 


92.42 


7 


85.00 


89.49 


7 


86.92 


90.96 


7 


88.88 


92-45 


6 


85.04 


89 52 


6 


86.96 


90.99 


6 


88.92 


92.48 


5 


85.08 


89-55 


5 


87.00 


91.02 


5 


88.96 


92-51 


4 


85.12 


89-58 


4 


87-04 


91.05 


4 


89.00 


92-54 


3 


85-15 


89.61 


3 


87.08 


91.08 


3 


89.04 


92-57 


2 


85.19 


89.64 


2 


87.12 


91. II 


2 


89.08 


92.60 


I 


85-23 


89.67 


I 


87-15 


91.14 


I 


89.12 


92.63 





85-27 


89.70 





87.19 


91.17 





89.16 


92.66 


0.8349 


85-31 


89-72 


0.8299 


87-23 


91.20 


0.8249 


89.19 


92.68 


8 


85-35 


89-75 


8 


87-27 


91-23 


8 


89.23 


92.71 


7 


85-38 


89.78 


7 


87-31 


91-25 


7 


89.27 


92.74 


6 


85.42 


89.81 


6 


87-35 


91.28 


6 


89.31 


92.77 


5 


85.46 


89.84 


5 


87.38 


91-31 


5 


89-35 


92.80 


4 


85-50 


89.87 


4 


87.42 


91-34 


4 


89-38 


92.83 


3 


85-54 


89.90 


3 


87.46 


91-37 


3 


89.42 


92.86 


2 


85-58 


89-93 


2 


87.50 


91.40 


2 


89.46 


92.89 


I 


85.62 


89.96 


I 


87-54 


91-43 


I 


89.50 


92.91 





85-65 


89-99 





87.58 


91.46 





89-54 


92.94 


'^-8339 


85.69 


90.02 


0.8289 


87.62 


91.49 


0.8239 


89.58 


92.97 


8 


85-73 


90.05 


8 


87.65 


91-52 


8 


89.62 


93.00 


7 


85-77 


90.08 


7 


87.69 


91-55 


7 


89.65 


93-03 


6 


85.81 


90.11 


6 


87-73 


91-57 


6 


89.69 


93-06 


5 


85-85 


90.14 


5 


87-77 


91.60 


5 


89-73 


93-09 


4 


85.88 


90.17 


4 


87.81 


91.63 


4 


89-77 


93-11 


3 


85.92 


90.20 


3 


87.85 


91.66 


3 


89.81 


93-14 


2 


85.96 


90.23 


2 


87.88 


91.69 


2 


89.85 


93-17 


I 


86.00 


90.26 


I 


87-92 


91.72 


I 


89.88 


93.20 





86.04 


90.29 





87.96 


91-75 





89.92 


93-23 



ALCOHOLIC BEl^ERyiCES. 673 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (C<w/wm<;J). 





Absolute Alcohol. | 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 






Spec. 






Spec. 


















Grav. 
at 


Per 


Per 


Grav. 
at 


Per 


Per 


Grav. 
at 


Per 


Per 


tefi^C 


Cent 


Cent 


iS.6°C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15. U V_/. 


by 


by Vol- 


by 


by Vol- 




by 


by Vol- 




Weight. 


ume. 




"Weight. 


ume. 




Weight. 


ume. 


0.8229 


89.96 


93.26 


0.8179 


91-75 


94-53 


0.8129 


93-59 


95-84 


8 


90.00 


93-29 


8 


91.79 


94.56 


8 


93-63 


95-87 


7 


90.04 


93-31 


7 


91.82 


94-59 


7 


93-67 


95-90 


6 


90.07 


93-34 


6 


91.86 


94-61 


6 


93-70 


95-92 


5 


90.11 


93 -.36 


5 


91.89 


94-64 


5 


93-74 


95-95 


4 


90.14 


93-39 


4 


91-93 


94.66 


4 


93-78 


95-97 


3 


90.18 


93-41 


3 


91.96 


94.69 


3 


93.81 


96.00 


2 


90.21 


93-44 


2 


92.00 


94.71 


2 


93-85 


96-03 


I 


90.25 


93-47 


I 


92.04 


94.74 


I 


93-89 


96.05 





90.29 


93-49 





92.07 


94-76 





93-92 


96.08 


0.8219 


90.32 


93-52 


0.8169 


92.11 


94-79 


0.8119 


93-96 


96.11 


8 


90.36 


93-74 


8 


92-15 


94.82 


8 


94.00 


96.13 


7 


90-39 


93-57 


7 


92.18 


94-84 


7 


94-03 


96.16 


6 


90-43 


93-59 


6 


92.22 


94.87 


6 


94.07 


96.18 


5 


90.46 


93.62 


5 


92.26 


94-90 


5 


94.10 


96.20 


4 


90-50 


93-64 


4 


92.30 


94.92 


4 


94.14 


96.22 


3 


90-54 


93-67 


3 


92-33 


94-95 


3 


94.17 


96.25 


2 


90.57 


93-70 


2 


92-37 


94.98 


2 


94.21 


96.27 


I 


90.61 


93-72 


I 


92.41 


95-00 


I 


94.24 


96.29 





90.64 


93-75 





92.44 


95-03 





94-28 


96.32 


0.8209 


90.68 


93-77 


0.8159 


92.48 


95.06 


0.8109 


94-31 


96-34 


8 


90.71 


93.80 


8 


92.52 


95-08 


8 


94-34 


96-36 


7 


90-75 


93.82 


7 


92.55 


95-11 


7 


94-38 


96.39 


6 


90.79 


93-85 


6 


92-59 


95-13 


6 


94.41 


96.41 


5 


90.82 


93-87 


5 


92.63 


95.16 


5 


94.45 


96.43 


4 


9c. 86 


93-90 


4 


92.67 


95-19 


4 


94.48 


96.46 


3 


90.89 


93-93 


3 


92.70 


95-21 


3 


94-52 


96.48 


2 


90-93 


93-95 


2 


92-74 


95-24 


2 


94-55 


96.50 


I 


90.96 


93-98 


I 


92.78 


95-27 


I 


94-59 


96-53 





91.00 


94.00 





92.81 


95-29 





94.62 


96-55 


0.8190 


91.04 


94-03 


0.8149 


92.85 


95-32 


0.8099 


94-65 


96-57 


8 


91.07 


94-05 


8 


92.89 


95-35 


8 


94.69 


96.60 


7 


91.11 


94.08 


7 


92.92 


95-37 


7 


94.73 


96.62 


6 


91.14 


94.10 


6 


92.96 


95-40 


6 


94.76 


96.64 


5 


91. t8 


94-13 


! 5 


93-00 


95-42 


5 


94.80 


96.67 


4 


91.21 


94-15 


1 4 


93-04 


95-45 


4 


94-83 


96.69 


3 


91-25 


94.18 


1 

3 


93-07 


95-48 


3 


94.86 


96.71 


2 


91.29 


94-21 


2 


93." 


95-50 


2 


94.90 


96.74 


I 


91.32 


94-23 


1 I 


93-15 


95-53 


I 


94-93 


96-76 





91.36 


94-26 


1 


93.18 


95-55 





94-97 


96.78 


0.8189 


91-39 


94-28 


0.8139 


93-22 


95-58 


0.8089 


95.00 


96.80 


8 


91-43 


94-31 


8 


1 93-26 


95-61 


8 


95.04 


96.83 


7 


91.46 


94-33 


7 


1 93-30 


95-63 


7 


95-07 


96-85 


6 


91.50 


94-36 


6 


I 93-33 


95-66 


6 


95-" 


96.88 


5 


91-54 


1 94-38 


5 


93-37 


95-69 


S 


95-14 


96.90 


4 


91-57 


; 94-41 


4 


93-41 


95-71 


4 


95-18 


96-93 


3 


91.61 


' 94-43 


3 


93-44 


95-74 


3 


95-21 


96.95 


2 


91.64 


1 94-46 


2 


93-48 


95-76 


2 


95-25 


96.98 


I 


91.68 


1 94-48 


I 


93-52 


95-79 


I 


95-29 


97.00 





91.71 


94-51 


i 


93-55 


95.82 





95-32 


97.02 



674 FOOD INSPECTION AND ANALYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Co«/f;n/f(f). 





Absolute Alcohol. 




Absolute Alcohol. | 


Spec. 


Absolute Alcohol. 


Spec. 






Spec. 










Orav 


Per 


Per 


Grav. 


Per 


Per 


Grav. 

at 

T C ffi C 


Per 


Per 


at 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


Cent 


Cent 


I5.6°C. 


by 


by Vol- 


by 


by Vol- 


IJ3.U \.y. 


bv 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 





Weight. 


ume. 


0.8079 


95-36 1 


97-05 


0.8029 


97.07 


98.18 1 


0.7979 


98.69 


99.18 


■; 


95-39 


97.07 


8 


.97.10 


98.20 


8 


98.72 


99.20 


7 


95-43 


97.10 


7 


97-13 


98.22 


7 


98-75 


99.22 


6 


95-46 


97.12 


6 


97.16 


98.24 


6 


98.78 


99.24 


5 


95-5° 


97-15 


5 


97.20 


98.27 


5 


98.81 


99.26 


4 


95-54 


97.17 


4 


97-23 


98.29 


4 


98.84 


99.27 


3 


95-57 


97.20 


3 


97.26 


98.31 


3 


98.87 


99.29 


2 


95.61 


97.22 


2 


97-30 


98.33 


2 


98.91 


99-31 


I 


95-64 


97.24 


I 


97-33 


98.35 


I 


98.94 


99-33 





95-68 


97.27 





97-37 


98.37 





98.97 


99-35 


0.8069 


95-71 


97.29 


0.8019 


97.40 


98.39 


0.7969 


99.00 


99-37 


8 


95-75 


97-32 


8 


97-43 


98.42 , 


8 


99-03 


99-39 


7 


95-79 


97-34 


7 


97.46 


98-44 1 


7 


99.06 


99.41 


6 


95-82 


97-37 


6 


97-50 


98.46 


6 


99.10 


99-43 


5 


95.86 


97-39 


5 


97-53 


98.48 


5 


99-13 


99-45 


4 


95-89 


97.41 


4 


97-57 


98.50 


4 


99.16 


99-47 


3 


95-93 


97-44 


3 


97.60 


98.52 


3 


99.19 


99-49 


2 


95-96 


97.46 


2 


97-63 


98.54 


2 


99-23 


99-51 


I 


96.00 


97-49 


I 


97.66 


98.56 


I 


99.26 


99-53 





96-03 


97-51 





97.70 


98.59 




i 


99.29 


99-55 


0.8059 


96.07 


97-53 


0.8009 


97-73 


98.61 


0-7959 


99-32 


99-57 


8 


96.10 


97-55 


8 


97.76 


98.63 


8 


99-36 


99-59 


7 


96.13 


97-57 


7 


97.80 


98.65 


7 


99-39 


99.61 


6 


96.16 


97,60 


6 


97-83 


98.67 


6 


99-42 


99-63 


5 


96.20 


97.62 


5 


97.87 


98.69 


5 


99-45 


99-65 


4 


96.23 


97.64 


4 


97.90 


98.71 


4 


99.48 


99-67 


3 


96.26 


97.66 


3 


97-93 


98.74 


3 


99-52 


99-69 


2 


96.30 


97.68 


2 


97.96 


98.76 


2 


99-55 


99.71 


I 


96-33 


97.70 


1 


98.00 


98.78 


I 


99-58 


99-73 





96.37 


97-73 





98.03 


98.80 





99.61 


99-75 


0.8049 


96.40 


97-75 


0.7999 


98.06 


98.82 


0.7949 


99-65 


99-77 


8 


96-43 


97-77 


8 


98.09 


98.83 


8 


99.68 


99.80 


7 


96.46 


97-79 


7 


98.12 


98.85 


7 


99.71 


99.82 


6 


96.50 


97.81 


6 


98.16 


98.87 


6 


99-74 


99.84 


5 


96-53 


97-83 


5 


98.19 


98.89 


5 


99.78 


99.86 


4 


96-57 


97.86 


4 


98.22 


98.91 


4 


99.81 


99.88 


3 


96.60 


97.88 


3 


98.25 


98.93 


3 


99.84 


99.90 


2 


96.63 


97-90 




98.28 


98.94 


2 


99-87 


99.92 


I 


96.66 


97.92 


I 


98.31 


98.96 


I 


99-90 


99-94 





96.70 


97-94 





98-34 


98.98 





99-94 


99.96 


0.8039 


96-73 


97.96 


0.7989 


98-37 


99.00 


0-7939 


99-97 


99.98 


8 


96.76 


97.98 


8 


98.41 


99.02 




. 




7 


96.80 


98.01 


7 


98.44 


99.04 




Abs. 


Ale. 


6 


96.83 


98-03 


6 


98.47 


99-05 


0.7938 


100.00 


100.00 


5 


96.87 


98-05 


5 


98.50 


99-07 








4 


96.90 


98.07 


4 


98-53 


99-09 








3 


96-93 


98.09 


3 


98.56 


99.11 








2 


96.96 


98.11 


2 


98-59 


99-13 








I 


97.00 


98.14 


I 


98.62 


99-15 











97-03 


98.16 





98.66 


99.16 









/iLCOHOLIC BEVERAGES. 



675 



(4) Determination of Alcohol by the Ebullioscope or Vaporimeter 
is based on the variation in boiling-point of mixtures of alcohol and water, 
in accordance with the amount of alcohol present. There are various 
forms of this instrument, one of the simplest and most convenient being 
that of Salleron, Fig. 113, the apparatus being known in France as an 








Fig. 113.— Salleron's Ebullioscope and Scale for Calculation of Results. 

ebulliometer. This consists of a jacketed metallic reservoir, heated by 
a lamp placed beneath, and fitted with a return-flow condenser at the 
top and with a delicate thermometer graduated in tenths of a degree. 

As the boiling-point of water varies with the atmospheric pressure, 
it is necessary to determine the actual boiling-point corresponding with 
the barometric conditions each time a series of determinations are made. 



6/6 FOOD INSPECTION AND ANALYSIS. 

This is done by boiling a measured portion of distilled water in the reser- 
voir, and carefully noting the tempera t'ure when it becomes constant. 

The reservoir is then rinsed out with a little of the liquor to be tested, 
after which a measured amount of this liquor is boiled in the reservoir 
and the temperature again noted. A sliding scale (Fig. 113) accompanies 
the instrument, having three graduated parts as shown. The central 
movable portion is graduated in degrees and tenths of a degree centi- 
grade, the part at the left has the per cent of alcohol corresponding to 
the temperature in the case of simple mixtures of alcohol and water, 
while the part at the right is used for reading the per cent in the case of 
wine, cider, beer, etc., which have a considerable residue. The movable 
scale bearing the degrees of temperature is first set with the actual tem- 
perature of boiling water (as ascertained) opposite the o mark on the 
stationary scale. Suppose the temperature of boiling water has been 
found to be 100.1°. The scale is in this case set as shown in Fig. 113. 
Suppose also the temperature of boiling of the wine to be tested is 
found to be 89.3°. From the right-hand scale the corresponding per cent 
of alcohol is found to be 17.2. 

When the liquor to be tested contains more than 25% of alcohol, it 
is necessary to dilute with a measured amount of distilled water and 
calculate the per cent from the dilution. 

When once the boiling-point of water has been determined for a given 
barometric pressure, it is unnecessary to change the position of the slid- 
ing scale during a series of alcohol determinations unless that pressure 
changes. 

Expression of Results. — Some confusion is caused by the three ways 
of expressing results of the alcohol determination, whether as per cent by 
weight, per cent by volume, or grams per 100 cc. The particular mode 
adopted should depend upon the nature of the case and upon the prevail- 
ing custom. In laboratory analyses, unless otherwise qualiiied, the simple 
expression of "per cent" usually implies per cent by w^eight, and for 
the reason that this conforms with other determinations, the adoption 
of the weight-percentage plan is perhaps most natural to the chemist on 
the grounds of uniformity. 

In enforcing the laws regulating the liquor traffic, the custom leans 
to volume percentage, and many of the laws are based on the ' ' volume 
of alcohol at 60° F." (see p. 656). 

In recent years many European analysts have adopted the custom of 
expressing results of analyses of wines and other liquors in. grams per 



ALCOHOLIC BEl^ERAGES. 677 

TOO cc. and, in order to have a common basis of comparison between 
the composition of American and of European wines, this manner of 
expression has to some extent been adopted in the United States. 

Proof-spirit in the United States is an alcoholic liquor containing 50% 
of absolute alcohol by volume at 15.6° C. A common method of express- 
ing alcohol is in "degree proof" or simply " proof," which In the United 
States is twice the per cent of alcohol by volume. TTius, 91.3 proof or 
degree proof is the same as 45.65% alcohol by volume. 

English Proof-spirit differs from that in the United States in that it 
contains 49.24% by weight, or 57.06% by volume of ab.solute alcohol at 
15.6° C. Strength is expressed in degrees over or under proof. Thus 
liquor 20° under proof has 80 parts by volume of proof-spirit and 20 parts 
of water at 15.6° C, while 20° under-proof means that 100 volumes of the 
liquor have to be diluted to 120 volumes with water to yield proof-spirit. 
To calculate the per cent by volume of English proof-spirit from the per 
cent of alcohol by volume, divide the latter by 0.5706, or multiply it by 

I-7525- 

Direct Determination of Extract.^In licjuors having a high sugar 
content, the extract or total solids cannot be determined accurately by 
evaporation at the temperature of boiling water, owing to the dehydra- 
tion of the reducing sugars at temperatures exceeding 75°. When extreme 
accuracy is required, such liquors should be dried in vacuo at 75°, or in 
a McGill oven (p. 586). 

Approximate results satisfactor}^ in most cases are obtained by heat- 
ing for two and one-half hours 10 grams of the liquor in a tared platinum 
dish at the temperature of boiling water. If the results are to be expressed 
in grams per 100 cc, instead of weighing out 10 grams, 10 cc. of the liquor 
are measured by a pipette into a tared dish. With distilled liquors having 
low residues, accurate results are obtainable by direct evaporation at 
100°, using preferably 25 grams or 25 cc. according as the result is to be 
expressed in per cent l)y weight or grams per 100 cc. 

Extract in wine and beer is more readily calculated indirectly from 
iheir specific gravity as noted elsewhere. 

Determination of Ash. — The residue from the determination of the 
extract is incinerated to a white ash in the original dish at a low red heat, 
either over a Bunsen flame or in a mufifle. The dish is finally cooled in 
a desiccator and weighed. 

Preservatives and Artificial Sweeteners in liquors are identified as 
described in Chapters XVIII and XIX. 



678 



FOOD INSPECTION AND ANALYSIS. 



FERMENTED LIQUORS. 

The fermented juices of many varieties of fruits and berries furnish 
beverages more or less popular in various localities, especially for home 
consumption, though, with the exception of the products of the apple and 
the grape, few of them are found on the market. The following table 
shows the average percentage of sugar and free acid in the expressed 
juice or must of fruits, according to Fresenius, arranged in the order 
of their sugar content: 





Per Cent Sugar. 


Per Cent Free 
Acid as Malic. 




1-99 
2.13 
2.80 
4.18 
4.84 
5-32 
6.89 
7-30 
7-56 
8.00 

8.43 

9.14 

10.00 

10.44 

15-30 
16.15 


0.85 
1.29 
1.72 
0.67 
1.80 
1.42 
1-57 
2-43 
1.08 

1-63 
0.09 
0.82 
2.02 
1-52 
0.88 
0.80 




Plums 












German prunes 

















CIDER. 

Cider is the expressed juice of the apple. When fresh and before 
fermentation has set in, it is known as sweet cider, but it does not long 
remain in this condition, developing after a good fermentation from 3 to 
6 per cent of alcohol by volume. 

The predominating yeast under the influence of which the fermenta- 
tion of cider takes place is Saccharomyces apiculatus, found in consider- 
able quantity on the outside of the apples as well as in the soil in which 
the trees grow. 

Process of Manufacture. — The best cider is made from ripe fruit, 
taking care to avoid the green and the rotten apples, both of which impair 
the quality of the product. After gathering, the apples are best allowed to 
stand in piles until perfectly ripe, being kept under cover. If exposed 
to the weather, certain of the yeast organisms found on the skins of the 
apples that are useful in promoting subsequent fermentation would be 



ALCOHOLIC BEI^ERAGES. 



679 



washed off. As a rule the apples commonly used by farmers for cider- 
making are those that are unsalable or unfit for other purposes, beino- 
chiefly windfalls or bruised and imperfect fruit. The apples are usually 
first crushed in a mill to a coarse pulp, which is afterward subjected to 
pressure in a suitable press and the juice thus extracted. 

In this country but little attention is paid to the after processes the 
juice being usually transferred directly to barrels, which are not always 
particularly clean, and allowed to ferment spontaneously in a convenient 
place, subject to changes in temperature. There is little wonder that 
cider so made will keep but a short time and quickly goes over into vinegar, 
unless salicylic acid or other antiseptic is added. 

In France more care is taken to regulate the temperature of fermen- 
tation, to insure absolute cleanness of aU receptacles, and to separate 
out contaminating impurities. A preliminar}' fermentation is usually 
given to the juice in open vats, during which the yeast spores are 
developed, while impurities separate out both by rising to the surface 
and by settling to the bottom, care being taken to avoid the develop- 
ment of acetic fermentation. At the proper time the juice is "racked 
ofi'" or drawn from the clear portion between the top and bottom, trans- 
ferred to scrupulously clean barrels, and allowed to undergo a second 
fermentation at a lower temperature than before. 

Sometimes the "racking off" is repeated, and the juice is further 
clarified by "fining'' or treating -with isinglass, which carries down certain 
albuminous substances. 

Cider thus made is capable of keeping a \tr\ long time. 
In England cider is sometimes "fined" by treatment with milk, one 
quart of the latter being added to eighteen gallons of cider. 

The apple pomace, left as a residue, is generally steeped in water 
and repressed. The juice from the second pressing is occasionallv added 
to the first for cider manufacture, but more often is concentrated and 
made into apple jelly, or used as a fortifier for vinegar to make up 
deficiency in solids. 

Composition of Cider. — The following tables, due to Browne,* show 
the chemical composition of the freshly expressed juice of several 
American varieties of apple, as well as that of a few fermented samples 
of cider of known purity. 



* Peiin. Dept. of Agric, BuL 58. 



68o 



FOOD INSPECTION /iND /IN A LYSIS. 
APPLE JUICES. 



acb 



ye 

,0 n 



S-^.2 



-> ^ 

5? • • CD 

■*-JrOr2 4J 

Pi 



Red astrachan . . . . 

Early harvest 

Yellow transparent 
Early strawberry. . 

Sweet bough 

Baldwin, green. ... 

ripe 

Ben Davis 

Bellflower 

Tulpahocken 

Unknovm 



-05317 
.05522 
.05020 
.04949 
.04979 
.04882 
.07362 

-05389 
.06270 
.05727 
.05901 



11.78 
13.29 
II. 71 
II. 81 
11.87 
II .36 
16.82 
12.77 
14.90 
13-94 
13-75 



6.87 


3- 


7-49 


3- 


8.03 


2. 


5-47 


4- 


7.61 


3- 


6.96 


I. 


7-97 


7- 


7. II 


3- 


9.06 


4- 


9.68 


3- 


10.52 


2. 



10.50 
11.46 
10.14 

9.68 

10.69 

8.59 

15.02 

10.96 

13-38 
12.79 
12.83 



10.69 
11.67 
10.24 
9.90 
10.85 

8.68 

15-39 
II. 16 
13.61 

12.95 
12.95 



1. 14 


0-37 


0.77 


0.90 0.28 


0.65 


0.86 ' 0.27 


0.44 


0.78 


0.24 


I. II 


0. 10 






1.24 


0.31 


1.22 


0.67 


0.26 


0.87 


0.46 


0.28 


1.07 


0.58 


0.28 


0.66 


0.26 


0.24 


0.49 


0.44 


0.26 


0.22 



23.72 
24.32 

19.24 
39-40 
36.16 

49.00 

39.20 

48.20 

44.18 



FERMENTED CIDER (MIXED APPLES). 





















Rotation, 




Specific 
Gravity. 


SoUds. 


Invert 
Sugar. 


Malic 
Acid. 


Acetic 
Acid. 


Alcohol. 


Pectin. 


Ash. 


400-mm. 

Tube, 
Ventzke 

Scale. 
Degrees 

to the 1 

Left. 


A... 


1.99805 


1-94 


0.19 


0.21 


0.24 


6.85 


0.03 


0.25 


2.30 


B... 
C... 


I. 00122 
1.00525 


2.71 
3.26 


0.19 
0.89 


0.24 
0.30 


0.42 
0.48 


4.67 


0.03 
0.05 


0.32 
0.29 


2-49 

5-28 


D. . 
E... 


I. 0007 I 
I . 005 1 2 


1-93 
2.71 


0.34 
0.24 


0.27 
0.29 


0.21 
1.96 


4-95 
4.26 


0.05 
0.06 


0.23 
0.36 


2.00 
1.76 



The following are summaries of the results of a large number of 
analyses of European apple juices made by Truelle, the quantities being 
expressed in grams per liter: 



Specific gravity 

Inveri sugar 

Sucrose 

Total fermentable sugars (as dextrose) 

Tannin 

Pectin and albuminous substances. 

Acidity (sulphuric acid) 



Mean. 



I .0760 

135-85 

25.0.1 

162.18 



12 



2.90 
14 



Minimum. 



1-0573 
108.38 

5-58 
119.22 
0.26 
o 
0.69 



Maximum. 



I.IIOO 
181. 81 
71.7 

231-57 
8.07 

23 
7.41 



y4LCOHOLIC BEVER/IGES. 



68l 



In the municipal laboratory of Paris, Sangle Ferriere has analyzed 
eleven samples of known-purity cider with the following results: 







F 2 c 

3 
^0 


P. 

|3 


Sugar per 
Liter. 


Polarization, 
Laurent. 


u 

p 


Alkalinity of 
Ash, as 
K2CO3 per 
Liter. 


Aciditv as 
H2SO4. 


• 


Si • 


sli 


'0 


•0 


S 


Mean 

Maximum 

Minimum. . . 


I. 0159 
I. 0410 
I. 0012 


3-9 
6.2 
i.i 


52.67 

114.00 

22.62 


21.31 
59-40 
Trace 


21.62 
60.80 

Trace 


-4°.26 

-11°. 20 




3.26 

4-32 
2.48 


2.56 
3-68 
2.04 


5-27 
6-59 
4.20 


2-55 
2-94 
1-47 



Six samples of bottled "sweet" cider purchased in Massachusetts 
were analyzed in the Food and Drug Laboratory of the Board of Health 
with the following results: 





Per Cent 

Alcohol by 

Weight. 


Per Cent 
Acid as 
Malic. 


Per Cent 
Extract. 


Maximum 


8.00 

3-55 
5-71 


0.72 
0.48 
0.58 


7-82 
2.42 
4.19 


Minimum 


Average 





Browne gives the following as the composition of the mixed ash of 
several varieties of apple: 



Ingredient. 



Per- 
cent- 
age. 



Ingredient. 



Per- 
cent- 
age. 



Potash (KjO) 

SodaCNaP) 

Lime (CaO) 

Magnesia (MgO) 

Oxide of iron (FeoOj) 

Oxide of aluminum (.\l2O3) 

Chlorine (CI) 

Silica (SiOj) 

Sulphuric acid (SO3) 

Phosphoric acid (PjOj) 

Carbonic acid (COg) 

Deduct oxygen equivalent to CI. 
Total 



55-94 
0.31 

4-43 
3-78 

0-95 
0.80 

0-39 
0.40 
2.66 
8.64 
21.60 



99.90 
.09 



99.81 






Potassium carbonate (KgCOg)... 
Potassium phosphate (K3PO4). .. 

Sodium chloride (NaCl) 

Calcium sulphate (CaSOJ 

Calcium oxide (CaO) 

Magnesium phosphate (Mg3P20^) 

Magnesium oxide (MgO) 

Ferric oxide (Fe203) 

Aluminum oxide (.^IgOg) 

Silica (SiOa) 



6.85 

14-55 
0.60 

4-52 
2.57 
6.97 
0.59 
0.95 
0.80 
0.40 



Total 99.80 



^82 FOOD INSPECTION AND /INALYSIS. 

Burcker* gives the following composition of the ash of cider: 

Per Cent. 

Silica 0.94 

Phosphoric acid 12 .68 

Lime 2.77 

Magnesia 2 .05 

Oxides of iron and manganese o. 94 

Potash 53.74 

Soda 1. 10 

Carbonic acid 25 . 78 



100.00 



Adulteration of Cider. — The Committee on Standards of the A. O. A. C. 
have submitted for adoption the following standards for cider: Alcohol 
not more than 8%, extract not less than 1.8% determined by evaporation 
in an open vessel at ordinary atmospheric pressure and at the tempera- 
ture of boiling water; ash not less than 0.2%. 

Entirely factitious cider made from other than apple stock is rarely 
found, though the product as sold is frequently of inferior quahty and 
adulterated. The chief adulterants are water and sugar, and the use of 
antiseptics is common, especially of salicylic and sulphurous, acids, sodium 
benzoate, and occasionally beta-naphthol. 

Sodium carbonate is sometimes added to cider to neutralize the acid 
and thus prevent acetic fermentation. An abnormally high ash (say 
in excess of 0.35%) would point toward the presence of added alkali. 

Watering is apparent when the content of alcohol, solids, and ash of 
the suspected sample are found to be considerably below the corre- 
sponding constants of pure cider. According to Sangle Ferriere, the 
following are the minimum figures for these constants in a pure cider, 
so that a sample may safely be pronounced as watered if they all 
run distinctly below; 

Alcohol 3% by volume 

Extract 1.8% 

Ash 0.17% 

Besides these determinations, it is useful also to determine the fixed 
and volatile acids. 

Caramel is to be looked for, especially in watered samples. Other 

* Les Falsifications des Substances Alimentaires, p. 176. 



/fLCOHOLIC BEVERAGES. 



6S- 



adulterants alleged to be of frequent occurrence in French cider, but 
not 'commonly found in this country are commercial glucose, tartaric acid 
(to increase the acidity of a watered product), and coal-tar colors. 

Absence or deficiency of malates is conclusive evidence of fraud, 
indicating the admixture of notable quantities of the juice of the second 
pressing of pomace. 

Sugar is rendered apparent by the right-handed polarization of the 
sample, pure cider always polarizing well to the left. If after inversion 
of a dextro-rotar\^ cider the polarization is still to the right, commercial 
glucose is indicated; if the reading after inversion is to the left, cane 
sugar has undoubtedly been added. 

Frequently the analyst has only to determine the alcohol, especially 
in cases of seizure, to ascertain whether or not there has been violation 
of the liquor laws. 

PERRY OR PEAR CIDER. 

This is a common French product, but is rarely if ever found on sale 
in this countr)', though sometimes made for home consumption. In 
composition and in method of manufacture it much resembles apple 
cider. It is also subject to the same forms of adulteration. 

The following table summarizes a number of analyses made by 
Truelle on pear juice, or must, amounts being exjDressed in parts per 
thousand : 



Specific gravity 

Invert sugar 

Sucrose 

Total fermentable sugars (as dextrose) . 

Tannin 

Pectin and albuminous substances. 

Acidity (as sulphuric acid) 



Mean. 



1.0845 

145-64 

36-74 

184.14 

1.78 

13.08 

1.47 



Maximum. 



1.0675 
108.10 
16.69 

143-78 



0.76 



Minimum. 



I.09S 
200 

61.41 
220 
-^.20 
18 
2.40 



The following analysis of champagne perry is taken from the Lancet 
of October i, 1892: 

Alcohol by weight i . 45 

Alcohol by volume i . 80 

Solids 11.00 

Ash 0.35 



684 *^00D INSPECTION AND ANALYSIS. 



WINE. 

Wine in its broadest sense is the fermented expressed juice of any 
fruit, though the term, unless otherwise restricted, is generally understood 
to apply to the juice of the grape. 

The organism present in grape juice that plays the chief part in its 
alcoholic fermentation is the Saccharomyces cllipsoideus, a yeast which 
exists on the skins of the grape. 

Process of Manufacture. — The grapes, which should be fully ripe,, 
are picked and sometimes sorted, according to the care that is taken in 
grading the product. They are also sometimes freed from the stems, 
which contain considerable tannic acid, and which when crushed with the 
grapes impart a certain astringency to the final product. The grapes are 
crushed either by machiner)^ or by the bare feet, and the juice is pressed 
out from the pulp in various ways, by screw or hydraulic press, or by the 
centrifugal process. 

A certain amount of juice runs off from the preliminary crushing 
known as the first run, and makes the choicest wine. The product from 
the pressure constitutes the second run, after which the pomace, by steep- 
ing in water and repressing, is made to yield an inferior juice used in 
vinegar-making. 

Red wines are made from dark grapes by fermenting the pulp, before 
pressing, with the skins, which by this treatment yield up their rich color 
{cenocyanin) to the juice. Besides the color, the skins contain also tannin. 
White wine is made from the pressed pulp, freed from the skins at once, 
or from the pulp of white grapes. The unfermented must constitutes 
from 60 to 80 per cent of the weight of the grape. 

Fermentation progresses most rapidly at a temperature between 25° 
and 30° C, but wine having a much finer bouquet is produced by slower 
fermentation, hence the must is allowed to ferment in open vats or tubs 
in cool cellars, at a temperature of from 5° to 15° till it settles out com- 
paratively clear, special care being taken to avoid development of acetic 
fermentation. At the end of the first or active fermentation, the wine 
is drawn off and allowed to undergo a second or slow fermentation in 
casks, during which most of the lees or crude argols, composed of potas- 
sium bitartrate, settle out, being insoluble in alcohol, and the characteristic 
bouquet or flavor of the wine is developed. Occasionally during this 
process the wine is racked or drawn off. 

Undesirable fermentations and vegetable fungus growth, which are 



ALCOHOLIC BEVERAGES. 



68s 



liable to occur at this time, are avoided as much as possible by usino- 
especially clean casks, which are frequently "sulphured" (or burnt out 
with sulphur) before being used. The wine is also sometimes clarified, 
or "fined," by treatment with gelatin, which mechanically removes many 
impurities by precipitation, or is subjected to pasteurization before finally 
being bottled or stored in casks. 

Classification of Wines. — ^Wines are either natural or jortified. Nat- 
ural wines are those which contain no added sugar or alcohol, but which 
Are exclusively the product of the simple juice, fermented under the best 
conditions, either till the sugar has been used up, or till the yeast food 
is exhausted, or until the yeast growth has been checked by the strength 
of the alcohol developed. When the alcohol content amounts to 14% 
by weight there can be no further fermentation due to yeast, so that this 
is the highest limit for natural wine. Examples of natural wines are 
hock and claret and many California wines. 

Fortified wines are those to which alcohol has been added, usually before 
the natural fermentation has been allowed to proceed to a finish. For 
this reason considerable sugar is usually left, and such wines are more 
often sweet. Examples of fortified wines are jMadeira, sherry, and port. 

Volatile ethers (products of volatile acids) predominate as a rule in 
natural wines, while fixed ethers (from the fixed acids as tartaric) are 
most characteristic in fortified wines. 

Wines are also variously classified according to characteristic proper- 
ties possessed by them, as still or sparkling, red or white, "dry" or sweet, 
etc. 

Still wines are those in which there is but little carbon dioxide remain- 
ing, so that they do not effervesce. Sparkling wines are more or less 
heavily charged with carbon dioxide, either naturally, as in the case of 
champagne, wherein the gas is formed by after-fermentation of added 
sugar in the corked bottle, or artificially, by carbonating them in a similar 
manner to "soda-water." 

Among the best-known red wines are those of Burgundy and the 
Bordeaux wines or clarets, while the Rhenish and Moselle wines and the 
Sautemes are examples of white wine. 

"Dry" wines are those in which the sugar has been exhausted by 
fermentation, while sweet wines possess a considerable amount of unfer- 
mented sugar. Whether or not an excess of sugar is left after fermenta- 
tion has stopped depends upon the amount of yeast food or nitrogenous 
substance present in the wine. When the proteins are exhausted by the 



686 



FOOD INSPECTION AND ANALYSIS. 



yeast, fermentation ceases, and for this reason gelatin and other nitrog- 
enous bodies are sometimes added to extend the period of fermentation. 
Sweet wines are often reinforced by the addition of sugar. Madeira, 
both red and white, are samples of dry wine, while port wine is one of 
the sweet variety. 

While most of our finer wines still come from France and Germany, 
large quantities of California wines are now being produced of an extremely 
high grade and of many varieties. 

Composition of Grape Must and of Wine. — Konig's analyses of a 
large number of grape musts from different sources are thus summarized: 





Specific 
Gravity. 


Water, 
Per Cent. 


Nitroge- 
nous Ma- 
terial. 


Sugar. 


Acid. 


Other 
Non-ni- 
trogenous 
Material. 


Ash. 


Minimum 


I . 0690 
1.2075 
I .1024 


51-53 
82.10 


O.II 
o.t:7 


12.89 

35-45 
19.71 


0.20 
1. 18 
0.64 


1.68 

11.62 

4-48 


0.20 


Maximum 


0.63 

0.40 


Mean. 


74.40 0.28 











Typical analyses of German, French, Austrian, Russian, Italian, and 
Spanish wines arc shown in the following table, also due to Konig: 









o <u 



rtH 









Germany: 

Moselle 

Rhine , 

Baden 

Wurtemburg, white wine 
' ' red wine . . 

Alsace 

Lorraine, red wine 

France : 

Red wine 

White wine 

Austria: 

Tyrol, red wine 

' • white wine 

Russia: 

Red wine 

White wine 

Italy 

Spain: 

Ordinary red wine 

Sweet wine 



9964 
0005 



9995 



9967 



9963 

9940 
9927 

9939 
9931 



1.0233 



7-99 
8.00 
6.65 
6.10 
4-73 
6-59 
8.08 

7.80 
8.30 

9.08 
8.84 

10.76 
11.96 
10.61 

12.30 
12.78 



2.24 
2.60 
2.16 
2.27 
2.64 
2.07 
2.27 

2.56 
3-03 

2.34 
1.87 

2.76 

2.568 

3-44 

3-53 
9.69 



0.79 
0.81 
0.91 

0-95 
1. 14 
0.696 
0.56 

0-57 



0.62 
0-S9 

0.56 
0.49 
0.52 

0.49 
0-59 



0.018 
0.095 
0.091 
0.018 
0.032 



0.20 

0.358 
0.262 
0.026 
0.168 



.052 

•155 



.142 
.100 



0.031 
0.095 



0.088 



0.30 



0.458 
1-44 

0.38 
6-55 



/fLCOHOLIC BEVERAGES. 



687 



Germany: 

Moselle 

Rhine 

Baden 

Wurtemburg, white wine 
" red wine. . 

Alsace 

Lorraine, red wine 

France : 

Red wine 

White wine 

Austria: 

Tyrol, red wine- 

' ' white wine 

Russia: 

Red wine 

White wine 

Italy 

Spain: 

Ordinary' red ■wine 

Sweet wine 



0.72 

0.85 

49 

57 

0.4O 



0-7,3 
0.97 

0.65 
Q-65 

0.64 
0-59 
0-45 

1.09 
0.63 



.028 
.019 



0.043 



0.021 
0.020 



0-175 

0.23 

0.207 

0-25 

0.25 

0.229 

0.185 

0.248 
0.25 

0.222 
0-175 



0.036 0.267 
.026 0.204 
0.29 



0.61 
0.74 



.036 0.068 
.046 0.085 

0.025I 

0.043 0.115 

0.040 0.108 

0-038J 

0.030 



o.oii 
0.017 



0.024 



0.030 
0.032 



0.106 



.101 
.010 



0.0271 

0.0221 0.077 

0.027 O.III 
0.030 0.086 
0.032i 0.H5 

0.027 0.242 
0.039 0.296 



0.009 
0.008 



0.02 
0.022 



0.017 



O.OI2i 
0.020 



0.009 0.02I 
0.08 



0.008 



.018 0.033 
.015 0.038 



0.023 
0.023 



0.019 

0.221 
0.212 



On- page 688 are given summaries of analyses of American wines, 
compiled from tables of analyses made by Bigelow.* 

Varieties of Wine. — Champagne is a selected, sweet, white "mne, 
clarified with gelatin, bottled with the addition of cane sugar, mixed with 
a little brandy, and tightly corked. Sometimes a small amount of yeast 
is also introduced. Fermentation is allowed to go on at a temperature 
of about 24° C, during which the wine is highly charged with carbon 
dioxide. The bottles are set on their side for some months, after which 
they are inverted till the sediment gathers above the cork, which by careful 
manipulation is quickly removed so as to throw out the sediment, and is 
afterward replaced and secured. Champagne contains from 8 to 10 
per cent of alcohol and is high in sugar. 

Claret is a light, red wine of a deep color, and is somewhat acid and 
astringent. In alcohol it varies from 8 to 13 per cent by volume. It has 
ver\^ little sugar and is high in volatile ethers. 

Madeira is a strong, white wine, possessing a refined, nutty, aromatic 
flavor when fully aged. It is generally fortified, containing from 17 to 
20 per cent of alcohol. It is named from the island which produces it. 

Sherry is a deep, amber-colored, sweet, Spanish wine, high in alcohol 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 59. 



688 



FOOD INSPECTION AND ANALYSIS. 



•qsy 



SUUOIOQ 
pUB illUUBX 



•spp^ojj 



•31Bqd[ng 
lunissB^oj 



•jBSng 
aupnpa^ 



vO CO o « 

M CO ro O 



r^O OOO QOO TtM ^OvO 

Tf>^ OLO O^tJ- <>f< fOlO 

•^M roO Wi-i flM ■^w 



0\ IH 



00 "T! 'to 

C< fO Tt lO 

ro O fO O 



o o 



NO 0> O IH 

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rt 1/-) 
loco 



o o 



in vo 

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to •* 



or- MCO OfO mO\ 

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cz: CO M o pooo r^co 

re O <eO o^i-i ^O 



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r-O NO 't 

M O M O 



W ■* NO Tt 

NO On On O 

00 lO M ID 

M O « O 



On On no On OnCO 
NO nO '^^nO i>*. O) 

LO O 0> O LO 01 



•U011B2UB[0<J 



t-i vo 

tN| O 

I I 



LO 01 

fO O 



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O CO <^- O 



t^ rt ro O 



I I 



E o 



•loBJixa 



■spiay 



00 O 



01 CO VO »H 

01 -^ \o on 



"^ W VO IH 



CO CO 
00 NO 
CO oo 



00 CO 
H lO 

I^ CO 



01 CO •* i-i 
NO O oo O 

r^ -Tj- CO 01 



oOt-~ NOt~- nOOn O" oooe 
0001 Ot^ LO" Ooo Onlo 
t--.ro r-»ro >Ooi i^M t— P) 



•Ol^lB-JJ 

(oqoojB 



00 oo 



•ui.i3oA[g 



•[oqooiv 



CO CO f^ oo NO •"t 

Ml- O NO ro 01 

O CO t^ M On OO 



lOON QiO NOrt- NOOl 

M fo 01 NO t^NO t^OO 



•suinjo^ 
Aq [ono3[v 



O ON CO o 



O CO «5 t^ 



•X^IABJQ 

oijpads 



On On 
On On 



NO M LO O 

On On O On 
On On O 0\ 



OO 

01 00 

O CO 

O On 



CO 01 

OO CO 

ooo 

O On 



O NO 

NO NO 

looo 



•saiduiBg 
JO aaqiuni^ 






^ iS 



^ s 



6 S 



.3 



T3 g 

g § fi 



S c S E 

3 Ji 2 3 

Sf-H S g 



C/2 



_ g 

CI. 5 



g oJ i g S 5 S 



gg^ 



S*^33a33Ji33 .33^h33 
g^ggi'ggp^gg "gg-ogg 
^ -e ■>< "S <u B 'S c B 'g 5:; ^ 'g 5 ^ 'S 



1^ 1^ p^ ^ 



^^ 



al .g O- rt . 



=« ni.E. 



ALCOHOLIC BEl^ERAGES. 



689 



(sometimes containing over 20%), being usually fortified. It is slightly 
acid and possesses much fragrance. Sherry is nearly always "plastered." 

Hocks are white German wines, mildly acid, containing 9 to 12 per 
cent of alcohol by volume. They have very little sugar, and rank among 
the highest of natural wines. The best-known varieties are Hockheimer 
and Johanisberger. 

Port {Viniim portense of the 1870 Pharmacopoeia) is a dark-purple, 
astringent wine, almost always fortified, and hence high in alcohol (from 
15 to 18 per cent by volume). It is much improved by aging, during 
which it looses considerable of its astringency. It contains a large amount 
of extract, from 2 to 6 per cent of the wine being sugar. The fixed ethers 
predominate over the volatile. 

Standards of Purity for Wine. — The ratio of volatile to fixed acids in 
pure wine should not exceed 1:3. A higher proportion of volatile acid 
shows the fact that acetic fermentation has set in. 

The presence of any considerable free tartaric acid would indicate 
the addition of this substance to the wine. 

The United States Pharmacopoeia has prescribed the following require- 
ments in the case of wines: For white wine {Vinuni album) the specific 
gravity at 15.6° should not be less than 0.990 nor more than i.oio; the 
extract oi residue at 100° should not be less than 1.5 nor more than 3%; as 
indicating the amount of free acid, not less than 3 nor more than 5.2 cc. 
normal potassium hydroxide should be required to neutralize 50 cc. of 
the wine, using phenolphthalein as an indicator; it should contain not less 
than 7 nor more than 12 per cent by weight of absolute alcohol; it should 
contain only traces of tannin. 

For red wine {Vinum ruhum) the specific gravity at 15.6° should 
not be less than 0.989 nor more than i.oio; the extract should not 
be less than i.(i% nor more than 3.5%; its limits as to acidity are 
the same as with white wine, eosin or fluorescin, however, being used 
as an indicator; in alcoholic strength, it should, like white wine, come 
within the limits of 7 and 12 per cent alcohol by weight. It should 
not be artificially colored, but should show the presence of tannic 
acid. 

The following are U. S. standards for wines: Wine is the product 
made by the normal alcoholic fermentation of the juice of sound, ripe' 
grapes, and the usual cellar treatment, and contains not less than 7 
nor more than 16 per cent of alcohol, by volume, and, in 100 cc. (20° C), 



690 FOOD INSPECTION /IND /INALYSIS. 

not more than o.i gram of sodium chloride nor more than 0.2 gram 
of potassium sulphate; and for red wine not more than 0.14 gram, and 
for white wine not more than 0.12 gram of volatile acids produced by 
fermentation and calculated as acetic acid. Red wine is wine contain- 
ing the red coloring matter of the skins of grape. White wine is wine 
made from white grapes or the expressed fresh juice of other 
grapes. 

Dry wine is wine in which the fermentation of the sugars is practically 
complete, and which contains, in 100 cc. (20° C), less than i gram of 
sugars, and for dry red wine not less than 0.16 gram of grape ash and 
not less than 1.6 grams of sugar-free grape solids, and for dry white 
wine not less than 0.13 gram of grape ash and not less than 1.4 grams 
of sugar-free grape solids. 

Fortified dry wine is dry wine to which brandy has been added, 
but which conforms in all other particulars to the standard of dry 
wine. 

Sweet wine is wine in which the alcoholic fermentation has been 
arrested, and which contains, in 100 cc. (20° C), not less than 
1 gram of sugars, and for sweet red wine not less than 0.16 gram of 
grape ash, and for sweet white wine not less than 0.13 gram of 
grape ash. 

Fortified sweet wine is sweet wine to which wine spirits have been 
added. By act of Congress, " sweet wine " used for making fortified 
sweet wine and " wine spirits " used for such fortification are defined 
as follows (sec. 43, Act. of October i, 1890, 26 Stat. 567, as amended 
by section 68, Act of August 27, 1894, 28 Stat. 509, and further 
amended by Act of Congress, approved June 7, 1906) : " That the 
wine spirits mentioned in section 42 of this act is the product resulting 
from the distillation of fermented grape juice to which water may have 
been added, prior to, during, or after fermentation, for the sole purpose 
of facihtating the fermentation, and economical distillation thereof, and 
shall be held to include the products from grapes or their residues, com- 
monly known as grape brandy; and the pure sweet wine, which may 
be fortified free of tax, as provided in said section, is fermented grape 
juice only, and shall contain no other substance whatever introduced 
before, at the time of, or after fermentation, except as herein expressly 
provided; and such sweet wine shall contain not less than 4 per cent 
of saccharine matter, which saccharine strength may be determined 



/ILCOHOLIC BEVERAGES. 691 

by testing with Balling's saccharometer or must scale, such sweet wine, 
after the evaporation of the spirits contained therein, and restoring the 
sample tested to original volume by addition of water: Provided, That 
the addition of pure boiled or condensed grape must, or pure crystaUized 
cane or beet sugar, or pure anhydrous sugar to the pure gi"ape juice 
aforesaid, or the fermented product of such grape juice prior to the 
fortification provided by this act, for the sole purpose of perfecting 
sweet wine according to commercial standard, or the addition of water 
in such quantities only as may be necessary in the mechanical operation 
of grape conveyors, crushers, and pipes leading to fermenting tanks, 
shall not be excluded by the definition of pure sweet wine aforesaid: 
Provided, however, That the cane or beet sugar, or pure anhydrous sugar, 
or water, so used shall not in either case be in excess of 10% of the 
weight of the wine to be fortified under this act: And provided further, 
That the addition of water herein authorized shall be under such regula- 
tions and limitations as the Commissioner of Internal Revenue, with 
the approval of the Secretary of the Treasury, may from time to time 
prescribe; but in no case shall such wines to which water has been 
added be eligible for fortification under the provisions of this act where 
the same, after fermentation and before fortification, have an alcoholic 
strength of less than 5% of their volume." 

Sparkling wine is wine in which the after part of the fermentation is 
completed in the bottle, the sediment being disgorged and its place 
supplied by wine or sugar liquor, and which contains in 100 cc. (20° C), 
not less than 0.12 gram of grape ash. 

Modified wine, ameliorated wine, corrected wine, is the product made 
by the alcoholic fermentation, with the usual cellar treatment, of a 
mixture of the juice of sound, ripe grapes with sugai (sucrose), or a 
syrup containing not less than 65% of sugar (sucrose), and in quantity 
not more than enough to raise the alcoholic strength after fermentation, 
to 11% by volume. 

Raisin wine is the product made by the alcoholic fermentation of 
an infusion of dried or evaporated grapes, or of a mixture of such 
infusion, or of raisins with grape juice. 

Adulteration of Wine. — Beverages purporting to be wine are 
sometimes found on sale that are entirely spurious, in that they con- 
tain little if any fermented grape juice. Apple cider is not infrequently 
the basis of such artificial products, and the following recipes given 



6,2 FOOD INSPECTION /IND ANALYSIS. 

by Brannl may be taken as tyi)ical of the composition of these wine 
substitutes: 

Burgundy. — Bring into a barrel 40 f|uaris of apple juice, 5 pounds 
of bruised raisins, \ pound of tartar, 1 fjuart of bilberry juice, and 3 
pounds sugar. Allow the whole to ferment, filling constantly up with 
cider. Then clarify with isinglass, add about i ounce of essence of bitter 
almonds, and after a few weeks draw off into bottles. 

Malaga Wine. — Apple juice, 40 quarts; crushed raisins, 10 pounds; 
rectified alcohol, 2 quarts; sugar solution, 2 quarts; elderberry flowers, 

1 quart; acetic ether, i ounce and 2 drachms. The desired coloration is 
effected by the addition of bilberry or elderberry juice; otherwise the 
process is the same as given for Burgundy. 

Sherry Wine. — Apple juice, 50 ([uarls; orange-flower water, about 

2 drachms; tartar, 2 ounces and 4 drachms; rectified alcohol, 3 r^uarts; 
crushed raisins, 10 pounds; acetic e'her, i ounce and 2 drachms. The 
process is the same as for Burgundy. 

Claret Wine. — Apple juice, 50 quarts; rectifled alcohol, 4 quarts; 
black currant juice, 2 (juarls; tariar, 2 ounces and 4 drachms. Color 
with bilberry juice. The further process is the same as for Bur- 
gundy. 

Artificial products similar in nature to the above are also mixed in 
varying proportions with pure wine. 

Presence of malates, as well as absence or diminution of total tartaric 
acid, is also indicative of cider. 

If the ash of the wine be submitted to the flame test, the sodium 
light will j)redominate in the case of pure wine, while if the basis of the 
sample be largely or wholly apple stock, the potash flame will be readily 
apparent. 

Wines are most frequently adulterated by "plastering," by watering, 
bv the addition of excessive amounts of sugar or glucose, by various flavor- 
ing principles, by coal-tar and vegetable colors, by antiseptics, and by 
added alcohol. 

Plastering. — By this term is understood the addition of gypsum or 
plaster of Paris to the must before fermentation, a practice in vogue in 
parls of France, Italy, and Spain. The reaction which takes place with 
the potassium bitartrate present in the wine is, according to Chancel, 
as follows: 



ALCOHOLIC BEl^ERAGES. 693 

2KHC,H,08 + CaSO, = CaC,H,Oe+ H3C,H,Oe+ K.SO,. 

Potassium Calcium Calcium Tartaric Potassium 

bitartrate sulphate tartrate acid sulphate 

Various advantages are said to result from this practice. The wine 
is clarified by the precipitation of the calcium tartrate, which mechan- 
ically carries down with it many impurities, the color of the wine is 
improved, since the solubility of the coloring principle present in the 
skins is increased, the fermentation is rendered more rapid and complete, 
and the keeping qualities of the wine are enhanced. The practice is, 
however, considered objectionable on account of the potassium sulphate 
which is left in solution in the wine, and in some countries plaster- 
ing is forbidden, or the amount of potassium sulphate limited by 
statute. 

The following are analyses of two Spanish wines made from the same 
grape juice, one of which was plastered. The results are expressed in 
grams per liter. 





Not Plastered. 


Plastered. 


Color 


Yellow 

23-3 
0.66 
2.06 

1.29 

0.41 


Bright red 

27-3 
0.61 

5.38 

0.17 

5 


Extract dried at 100° 

Insoluble ash 


Soluble ash 

The soluble ash containing 

Potassium carbonate . . . 

" sulphate. 



The effect of plastering is thus seen to distinctly increase the extract 
and the soluble ash. Any considerable amount of potassium sulphate 
is an indication of ])lastcring. 

Addition of Cane Sugar. — The term "chaptalizing" is applied in 
France to the addition to the must of cane sugar for the purpose of 
increasing the yield in alcohol. The addition of 1,700 grams of sugar 
to 1,000 liters of must is said to increase the alcoholic strength by 1%^ 
It was formerly customary to add with the sugar calcium carbonate^ 
to partially neutralize the acidity, but this is rarely practiced at present. 

The European wine-raising countries arc not disposed to regard the 
reinforcement of wine by added cane sugar in the must as in itself a fraud, 
unless water is also added, or unless some other form of aduhcration is 
practiced at the same time. In France, however, the addition of cane 



6(;4 lOUlJ INSl'UCIION .-INI) AN/ILYSIS. 

siif^ur is iicnnillcd rinly in wine foi- Kxal < onMiiiiiilion, and is rc'slri( led in 
amour)!. 

Tlir u ,<• <if < onnncrc i;il f^huose in wine- inslc.MJ of ( :inc sugar is not 
rcf^ardcd vvilli as iniuli favor, in view of tlic fad llial glucose- contains 
more or less nnfciiiii'iil al»lc nialUi, and inlroduccs dcxirin and various 
niinrral sails inio I In- wine. 

To ah(<'rlaiii I lie naliirc and c-xhiit of lli<- sn}^!;ars prcscnl in wine Is 
frc(|ucnlly of jMcat iniporlam c Mu( h information may l)c j^aincd from 
the direct and in\i il polari/al ion of I lie samjilc, as well as from the detcr- 
niinal ion ol icdn( inj', sn)',ar^.. 

liivcil ■A\y;A\ v. llif only legitimate sugar that should be present in 
genuine wine. In noiinal ferinenlalion the dextrose is more ((uickly 
destroyed than the le\ulose, hen( c liw polari/at i(»n of pure wine is a.lways 
left handed, indess all the sugar has heen termenled, in whi( h case the 
reading should We zero. 

Seventy live samples of California, ri'd wines, ( hielly ( laret, liin-gundy, 
khiue, and southern P'raiue types, analy/.ed in the I'.incau of Chemistry* 
of the U. S. Department of Agrieulfure, ])olari/ed from 0.5 to —2.1. 
LIi)wards of eighty samples of California white wine (of the; fypcs of 
Burgundy, Sautei"ne, and southern l''ran(c) were suhmitted to polariza- 
tion and all hut hmr were left handed. 'These h)ur (evidently abnormal) 
polari/.ed from o. to | 1. Most of them \aried from 0.1 to -3.5. 

'I'liirteen of the port wine types (C'alifornia) had a lelt handed polariza- 
tion of from I 1.7 to _'7.i. These apparently inntained large (|uan- 
lities of unfermented, inverted cane sugar. 

A shar|), right handed polarization wouhl indicate the presenc:e of 
eitlu'r lonnni-rc ial glucose or cane sugar. After inversion, il tin- reading 
is still rightdianded, ghuosi- is apparent, while if inversion t hanges the 
reading from right to left, cane sugar has undoubtedly heen added, iiy 
application of Clerget's formida the amount of cane sugar (an he estimated. 

The Watering of Wine, unless e.xcessive in <legree, is not always easy 
to i)rove, by reason of the varying composition of pure wine, and because 
the |>ractice is usually accompanied by other fornis of sophistication 
inlc-ndetl to com'I up evidcMucs of watering. Consideiable (|uantitie.S 
of added water aloiu- would usually be rendered apparent by a ])roi)or- 
tionate and abnormal lowering of the ahohol, extract, ash, acidity, and, 
iiideed, nearly all the constants. 

Gautier in his TraiU sur la Sophistication et I' Analyse des Vins claims 

* Hut. 5(j. 



/ii.<.()ii(>i.i<: m.^i-.N/iana 695 

)li;i,l the sum of Ibc w<-i)^liL in grains of ;i,l(;oliol in roo cc. and (h<: tolal 
;i( iflity, v.x\)U-.vi\ In ;^ratns of siilpliurir, ;i,rif| [Mtr lilcr, v;tri<:s witliiii very 
n;i,rrow liirn'l . in |<iiro wines, ni.rcly hdnj^ l«-low 1 / i>\- ;i.l*ovi; 17. A large 
ininilxr of ;i,nalys(r;-, marie by Gautler an'l olliers would seem f.o (onlirni tlii ,, 
•o lli;it in the majorily of cases, added wjilcr Wf)uld Ix; ;;lron^'Jy indi* ;itfd if 
I lie Mini of these two ronslanlH wan maleri;i.lly n;diif:(;d hclow 1 >,. Il i , 
more conservative lo ;i,do|»f. 12.5 as !). niininiuin liinil (or I lie Mini of the 
;il(o|iol ;i,nd tol;iI ;i,r id cxijre'V.ed as above. 

detection oi Added Alcohol. —As a result of th<-. Iindin;';. of ;i. rom 
niitlee ;i.|»|>ointed in I'' ranee to determine the ni;i,ltet oi ;i,d'|(d ajrojiol, 
il was submitted ih.it ;i rel;i,tir)n exi .tefl between the weight of the extr.'ict 
and that of the .ihohol in pun; wine. In the ease of red wines, if the 
wfri^ht of the alerdiol, divided by tin: wei;^^lit rjf the extraet Hjotli expresserl 
in grams per joo ccj exceeds 4.6, th(; a,ddition of ;i,l( ohol i, 'tronjdy indi 
<;),le*fl. With wliile wines, tfie qiK^lienl obt;i.iri<:d by dividin^^ the wei^'Jit 
of alcohol by weight of extraet should Moi exceed 0.6. If it do<- ,, .id'led 
;drohf4 is to be suspected. 

In the case of pbistered wines containing sulphate of jxHassium, or 
v/ines h;i.ving ;i,dded sugar, it is necessary to derluct from the total extract 
the weijdif of the rerluf:ing siigar and of the potassium sidjdiatr: a:', found 
He,, 'J. I ;'ni,ni for cjir h of these substancrr,;, the difference,, or reducr.-rl 
extract as it i-, c;i.lled, being used in this case in obtaining the ratio. 

Fruit Wines other than Grape. -Wines nv^stly of dormrstic manufac- 
ture are sometimes made; from snruill fruits, such as raspberries, straw- 
berri' , bhi/k berries, gooseberries, elderberries, anrl currants, as well as 
from dierrie-,, plums, and apricots. Wines ma^le from mo:4 of tliese 
fruits rearlily undergo acetic fermentation linless antiseptirs are added, 
or unless extreme care is taken in their manufactun; and kee[>ing. Frc- 
'pKmtly mixtures of various fruit juices are made So yiehl exiX'llent wine. 
Most of the sour fruits rt^inire a. libend admixture of sugar to produce 
an acceptalde v/ine. 

The following analysis of currant wine Is due to I''res<rniu8: 

Alcohol „ 10.01% 

Free acid o . 79% 

Sugar iJ.()^% 

Wate,'- 77''^(>7o 

The alcolir^lic content of other fruit winfis is thiis shown by lirannt: 

(j()<yM:\)ttrry wine. m .84% ala4u>l 

KMftrberry wine ^-79% * ' 

Orange wine 11.26% " 



696 FOOD INSPECTION /IND ANALYSIS. 

METHODS OF ANALYSIS OF WINE AND CIDER. 

For determination of specific gravity, alcohol, extract (by direct 
method), and ash, see pp. 657-676. 

Calculation of the Extract in Wine. — Attention has already been called 
to the diihculty in accurately determining the extract of sweet wines 
gravimetrically by evaporation. An approximate determination of the 
extract may be obtained by calculation from the specific gravity of the 
dealcoholized liquor, or one may use for this purpose the tables compiled 
by Windisch, and based on experiments made on drying wine in vacuo 
■at 75° C. In wines high in sugar, with more than 6% of extract, this 
'method is far more accurate than drying at 100°, and is to be recommended^ 

Evaporate a measured portion of the wine on the water-bath to 
one-fourth its volume, and dilute with water to exactly the volume 
measured. Determine the specific gravity of this dealcoholized liquid 
at 15.6°, and from the following table ascertain the extract corre- 
sponding. 

Determination of Total Acidity. — Carbonated beverages are first 
freed from carbon dioxide by agitation as described on page 658, after 
which 25 cc. of the sample are heated just to the boiling-point and titrated 
with tenth-normal sodium hydroxide, using in the case of white wine 
or cider phenolphthalein as an indicator. With red wine delicate Utmus- 
paper should be used. Total acidity is usually expressed, in the case 
of cider as malic, and of wine as tartaric acid. Each cubic centimeter 
of tenth-normal alkali corresponds to 0.0067 gram malic, or 0.0075 gram 
tartaric acid. Some chemists express total acidity in terms of sulphuric 
acid, each cubic centimeter of tenth-normal alkali being equivalent to 
0.0049 gram of sulphuric acid. 

Volatile Acids in all liquors are usually expressed as acetic, ahhough 
traces of propionic and other volatile acids may be present. 50 cc. of 
the cider or wine and a little tannic acid are transferred to a distilling- 
flask, Fig. 114, the stopper of which is provided with two tubes, one of 
which connects with the condenser, while the other, arranged to reach 
nearly to the bottom of the dislilling-flask, communicates ■v\ith a second 
flask which contains about 300 cc. of water. The contents of both flasks 
are brought to boiling, after which the flame under the distilling-flask 
is lowered, and steam from the water-flask is passed through the wine 
till about 200 cc. of distillate have collected in the receiving-flask. 
Titrate this wiih tenth-normal sodium hydroxide, using phenolphthalein. 



ALCOHOLIC BEVERAGES. 



69? 



EXTRACT IN WINE. 
[According to Windisch.] 



Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


I .0000 


0.00 


I .0065 


1.68 


I. 0130 


3.36 


1.0195 


S-04 


1 .0260 


6. 72 


1.0325 


8.40 


1 .0001 


0.03 


I .0066 


1.70 


I .0131 


3.38 


I .0196 


5-06 


1 .0261 


6.75 


I .0326 


8.43 


I .0002 


0.05 


I .0067 


1.73 


1 .0132 


3.41 


I. 0197 


S-09 


I .0262 


6.77 


1 .0327 


8.46 


1 .0003 


0.08 


I .0068 


1.76 


1.0133 


3.43 


I .0198 


5- II 


1 .0263 


6.80 


1.0328 


8.48- 


I . 0004 


0. 10 


1 .0069 


1.78 


I.OI34 


3.46 


I .0199 


S.14 


1 .0264 


6.82 


1.0329 


8. SI 


I .0005 


0.13 


I .0070 


1.81 


1.0135 


3-49 


I .0200 


5.17 


1.0265 


6.85 


1.0330 


8.53 


I .0006 


0.15 


I .0071 


1.83 


1.0136 


3.51 


I .0201 


5.19 


I .0266 


6.88 


1-0331 


8-56 


I .0007 


0.18 


I .0072 


1.86 


1.0137 


3-54 


I .0202 


5.22 


1 .0267 


6.90 


1 -033a 


8-';9 


I .0008 


0. 20 


1.0073 


1.88 


1.0138 


3.56 


1.0203 


5-25 


1.0268 


6-93 


1-0333 


8.61 


I .0009 


0.23 


I .0074 


1.91 


I. 0139 


3.59 


I .0204 


5-27 


I .0269 


6.9s 


I -0334 


8.64 


1 .0010 


0. 26 


1.0075 


1.94 


I .0140 


3.62 


I .0205 


S.30 


I .0270 


6.98 


1-0335 


8.66 


I .0011 


0.26 


I .0076 


1 .96 


1 .0141 


3.64 


I .0206 


5. 32 


1 .0271 


7.01 


1-0336 


8.69 


1 .0012 


0.31 


1.0077 


1.99 


I .0142 


3.67 


I .0207 


S.35 


I .0272 


7-03 


1.0337 


8.72 


I .0013 


0.34 


1 .0078 


2 . 01 


1.0143 


3.69 


I .0208 


S.38 


1-0273 


7 .06 


1-0338 


8.74 


I .0014 


0.36 


1 .0079 


2.04 


I. 0144 


3.72 


I .0209 


5-40 


1 -0274 


7-08 


1-0339 


8.77 


I. 0015 


0.39 


I .0080 


2 .07 


1.014s 


3-75 


I .0210 


5-43 


I -0275 


7.11 


1 - 0340 


8:79' 


1 .0016 


0.41 


I .0081 


2.09 


1 . 1 46 


3-77 


I .0211 


5. 45 


1 .0276 


7-13 


1-0341 


8.82 


I .0017 


0.44 


I .0082 


2.12 


1. 0147 


3.80 


I .0212 


5. 48 


1.0277 


7-16 


1.0342 


8-85 


1 .0018 


0.46 


1 .0083 


2.14 


I .0148 


3.82 


I .0213 


S-Si 


X .0278 


7-19 


1-0343 


8.87 


1 .0019 


0.49 


I .0084 


2.17 


I .0149 


3.8s 


I .0214 


5-53 


1.0279 


7.21 


1.0344 


8.90 


I .0020 


o. 52 


1.008s 


2.19 


1.0150 


3.87 


1-021S 


S.S6 


I .0280 


7-24 


1-0345 


8.92 


1 .0021 


0.54 


1 .0086 


2. 22 


1.0151 


3.90 


I .0216 


S-58 


I .0281 


7-26 


1-0346 


8.95 


I .0022 


0.57 


I .0087 


2.25 


1 .0152 


3.93 


I .0217 


S-61 


I .0282 


7.29 


I -0347 


8.97 


1.0023 


0-S9 


1.0088 


2 . 27 


1.0153 


3.95 


I .0218 


5-64 


I .0283 


7-32 


1-0348 


9.00 


I .0024 


0.62 


I .0089 


2.30 


1.0154 


3.98 


I .0219 


5-66 


I .0284 


7-34 


1.0349 


9 03 


T .0025 


. 64 


I .0090 


2.32 


1.0I55 


4. 00 


' I . 0220 


5.69 


1-0285 


7-37 


1.0350 


9.05 


I .0026 


0. 67 


I .0091 


2-35 


1. 0156 


4.03 


1 .0220 


5-71 


1.0286 


7-39 


I .0351 


9-08 


I .0027 


0.69 


I .0092 


2.38 


1-01S7 


4.06 


I .0222 


5. 74 


1 -0287 


7-42 


1-0352 


9. 10 


I .0028 


0.72 


I .0093 


2.40 


1.0158 


4.08 


1.0223 


5-77 


1.0288 


7-45 


1.0353 


9.13 


I . 0029 


0.75 


I .0094 


2.43 


I. 0159 


4.11 


I .0224 


5-79 


I .0289 


7.47 


I. 0354 


9. 16 


I .0030 


0.77 


1.009s 


2.45 


1 .0160 


4.13 


1.0225 


5.82 


I . 0290 


7.50 


I.035S 


9.18 


1.0031 


0.80 


I .0096 


2.48 


I .0161 


4. 16 


I .0226 


5-84 


I .0291 


7.52 


1.0356 


9.21 


1 .0032 


0.82 


I .0097 


2.50 


I .0162 


4.19 


I .0227 


S.87 


I .0292 


7-55 


1.0357 


9.25 


1.0033 


0.85 


I .0098 


2.53 


1-0163 


4.21 


I .0228 


5.89 


I .0293 


7.58 


1.0358 


9- 26 


1.0034 


0.87 

1 


I .0099 


2.56 


I .0164 


4.24 


I .0229 


S.92 


I .0294 


7 .60 


1.0359 


9-29 


1.0035 


. 90 


1 .0100 


2.58 


1.0165 


4. 26 


1 .0230 


5. 94 


I .0295 


7-63 


I .0360 


9-31 


I . 0036 


0.93 


1 .0101 


2 .61 


I .0166 


4.29 


I .0231 


5.97 


I .0296 


7.6s 


1 .0361 


9-34 


1.0037 


0.9S 


I .0102 


2.63 


I .0167 


4.31 


I .0232 


6.00 


1.0297 


7-68 


I .0362 


9-36 


I . 0038 


0.98 


1. 0103 


2.66 


I. 0168 


4.34 


1 1.0233 


6.02 


I .0298 


7.70 


1.0363 


9-39 


1.0039 


I .00 


1 .0104 


2.69 


I .0169 


4.37 


I .0234 


6.05 


I .0299 


7.73 


I .0364 


9-42 


I .0040 


1.03 


I .oios 


2.71 


I .0170 


4-39 


I-0255 


6.07 


I .0300 


7-76 


1.0365 


9-44 


I .0041 


i-os 


1 .0106 


2.74 


I .0171 


4-42 


1.0236 


6.10 


I .0301 


7.78 


I .0366 


9.47 


I .0042 


1.08 


I .0107 


2.76 


1 .0172 


4-44 


1.0237 


6.12 


1.0302 


7.81 


1.0367 


9.49 


1.0043 


I .11 


1 .0108 


2.79 


I. 0173 


4-47 


1.0238 


6.15 


1.0303 


7-83 


1-0368 


9. 52 


1.0044 


I -13 


I .0109 


2.82 


I. 0174 


4.50 


1.0239 


6.18 


1.0304 


7.86 


I 0369 


9.55 


1.004s 


I. 16 


1 .0110 


2.84 


1. 0175 


4-52 


I .0240 


6. 20 


1.0305 


7-89 


1.0370 


9.57 


I .0046 


I. I 8 


1 .0111 


2.87 


1 .0176 


4.55 


I .0241 


6.23 


I .0306 


7-91 


1-0371 


9.60 


I .0047 


I . 21 


I .01 12 


2.89 


I. 0177 


4.57 


I .0242 


6.25 


1.0307 


7-94 


1-0372 


9-62 


I .0048 


I .24 


1.0113 


2.92 


I .0178 


4.60 


1.0243 


6.28 


I .0308 


7-97 


1.0373 


9-6s 


1.0049 


1.26 


I .01 14 


2.94 


I. 0179 


4.63 


I .0244 


6.31 


I .0309 


7-99 


I.0374 


9.68 


I .0050 


1.29 


I .0115 


2.97 


I .0180 


4.65 


1.0245 


6.33 


1-0310 


8.02 


1.0375 


9.70 


I .0051 


1.32 


I .0116 


3 .00 


I .0181 


4.68 


I .0246 


6.36 


I .0311 


8-04 


1.0376 


9-73 


I .0052 


1.34 


1 .0117 


3.02 


I .0182 


4.70 


1.0247 


6.38 


1. 0312 


8-07 


1.0377 


9.75 


I-OOS3 


1.37 


I .0118 


3-05 


I .0183 


4-73 


I .0248 


6.41 


1.0313 


8-09 


1.0378 


9.78 


1.0054 


^.39 


1 .oi 19 


3-07 


I .0184 


4.7s 


1.0249 


6.44 


I. 0314 


8.12 


1.0379 


9.80 


1.0055 


1.42 


I .01 20 


3-10 


I .0185 


4.78 


I .0250 


6.46 


1-0315 


8.14 


1 .0380 


9.83 


1 .0056 


1-45 


1 .0121 


3.12 


I. 0186 


4.81 


1.0251 


6.49 


1 .0316 


8.17 


I .0381 


9.86 


1.0057 


1.47 


I .0122 


3. IS 


I .0187 


4.83 


I .0252 


6.51 


1.0317 


8.20 


I .0382 


9.88 


I .0058 


1.5° 


1.0123 


3.18 


I. 0188 


4.86 


I02S3 


6.54 


I .0318 


8.22 


1.0383 


9.91 


1 .0059 


1.52 


I .0124 


3 .20 


I .0189 


4.88 


I. 0254 


6.56 


1.0319 


8.25 


1.0384 


9.93 


1 .0060 


1-55 


I .0125 


3.23 


I .0190 


4.91 


1-0255 


6.59 


1 .0320 


8.27 


1.0385 


9.96 


I .0061 


1-57 


I .01 26 


3.26 


I .0191 


4-94 


I .0256 


6.62 


1.0321 


8.30 


1 .0386 


9.99 


1 .0062 


I .60 


1.0127 


3.28 


I .0192 


4.96 


1-0257 


6.64 


1.0322 


8.33 


1.0387 


10.01 


I .0063 


1.63 


I .0128 


3-31 


I .0193 


4-99 


I -0258 


6.67 


1.0323 


8.35 


1.038S 


10.04 


I .00O4 


1.6s 


1.0129 


3-33 

1 


I .0194 


5-OI 


1.0259 


6.70 


1.0324 


8.38 


1.0389 


10.06 



698 



FOOD INSPECTION AND ANALYSIS. 
EXTRACT IN V^IHY.— {Continued). 



Specific Ex- 
Gravity, tract. 


Specific 


Ex- 1 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Gravity- 


tract. Gravity. 1 


tract. Gravity. ' 


tract. 


Gravity. 


tract. iGravity.l 


tract. 


T.03Q0 10.09 1 

1. 0391 10. II 

1 .0392 10.14 


1-0455 


11.78 ' 


1.0520 


13.47 


1-0585 


15.16 


1 .0650 


16.86 


I .0715 


18.56 


I -0456 


II. 81 1 


I .0521 


13.49 


1.0586 


15.19 


I .0651 


16.88 


I .0716 


18.58 


1 -0457 


11.83 


I .0522 


13-52 


1.0587 


15-22 


I .0652 


16.91 


I. 0717 


18.61 


1.0393 
1.0394 


10. 17 


1.0458 


11.86 ; 


1-0523 


13-55 


1.0588 


15-24 


1 .0653 


16.94 


I .0718 


18.63 


10. 19 


1-0459 


11.88 ' 


1-0524 


13-57 


1.0589 


IS-27 


I .0654 


16.96 


I. 0719 


18.66 


I - 0395 


j 
10.22 I .0460 


II .91 ! 


1.052s 


13.60 


1.0590 


15-29 


1.065s 


16.99 


I .0720 


18.60 


I .0396 


10. 25 : 1.0461 


11-94 


I .0526 


13.62 


1.0591 


15-32 


I .0656 


17 .01 


I .0721 


18.71 


I • 0397 


10.27 [l I .0462 


11.96 j 


1-0527 


13-65 


1.0592 


15-35 


1.0657 


17.04 


I .0722 


18.74 


1 .0398 


10. 30 


1-0463 


11.99 \ 


I .052S 


13-68 


1.0593 


15-37 


1.0658 


17.07 


1 .0723 


1S.76 


.:i.o399 


10.32 


I . 0464 


12.01 1 

1 


1.0529 


13.70 


1.0594 


15-40 


1.0659 


17.09 


1.0724 


18.79 


'1 . 0400 


10. 35 


I .0465 


12 .04 


1-0530 


13-73 


1.059s 


15-42 


I .0660 


17.12 


1.0725 


18.82 


1 . 0401 


10.37 


I .0466 


12.06 


I .0531 


I3-7S 


I .0596 


15-45 


I .0661 


17.14 


I .0726 


18. 84 


1 .0402 


10.40 


1.0467 


12.09 


1 .0532 


13.78 


1.0S97 


15-48 


I .0662 


17.17 


1.0727 


18.87 


I . 0403 


10.43 


I .0468 


12.12 


1.0533 


13-81 


1 .0598 


lS-50 


I .0663 


17 . 20 


1.072S 


iS.oo 


1.0404 


10. 45 


I .0469 


12.14 


1-0534 


13-83 


1.0599 


15-53 


I .0664 


17.22 


1.0729 


1S.92 


I .0405 


10.48 


I .0470 


12.17 


I-053S 


13-86 


I .0600 


15-55 


1.0665 


17.25 


1.0730 


18. OS 


I . 0406 


10.51 


1-0471 


12.19 


1-0536 


13-89 


I .0601 


15-58 


1.0666 


17.27 


1.0731 


18.07 


I .0407 


10.53 


1.0472 


12.22 


I-OS37 


13-91 


I .0602 


15.61 


I .0667 


17.30 


1.0732 


19 .00 


1 .040S 


10.56 


1.0473 


12.25 


1.0538 


13-94 


1.0603 


15-63 


1.0668 


17.33 


1.0733 


1903 


1 .0409 


10.58 


1.0474 


12.27 


1-0539 


13.96 


I .0604 


15.66 


I .0669 


17.3s 


1.0734 


19.05 


I .0410 


10.61 


1-0475 


12.30 


1.0540 


13-99 


I .0605 


15.68 


I .0670 


17.38 


1.073s 


19.08 


1 .041 1 


10.63 


1.0476 


12.32 


I -0541 


14.01 


I .0606 


15.71 


I .0671 


17.41 


1.0736 


19. 10 


I . 04T 2 


10.66 


1-0477 


12.35 


1-0542 


14.04 


I .0607 


15.74 


I .0672 


17-43 


I .0737 


1913 


I .041 3 


10 .69 


1.0478 


12.38 


1-0543 


14.07 


I .0608 


15.76 


1.0673 


17.46 


1.0738 


19-16 


1 .0414 


10.71 


1.0479 


12.40 


1.0544 


14.09 


I .0609 


15.79 


I .0674 


17.48 


I.0739 


19. 18 


I .0415 


10.74 


1 .0480 


12.43 


I. 054s 


14. 12 


I .0610 


15.81 


I .0675 


17-51 


I .0740 


19-21 


I .0416 


10.76 


I .0481 


12.45 


1.0546 


14.14 


1 .061 1 


15.84 


I .0676 


17-54 


1.0741 


19.23 


I .041 7 


10.79 


1 .0482 


12.48 


I -0547 


14.17 


I .0612 


15.87 


1.0677 


17.56 


1.0742 


19- 26 


I .0418 


10.82 


I .0483 


12.51 


I . 0548 


14. 20 


I. 0613 


15.89 


1.0678 


17-59 


1.0743 


19.29 


I. 0419 


10.84 


1.0484 


12-53 


I. 0549 


14. 22 


I .0614 


15.92 


I .0679 


17 .62 


1.0744 


19-31 


I .0420 


10.87 


1.048s 


12.56 


1.0550 


14.25 


I .0615 


15.94 


I .0680 


17.64 


1.0745 


19-34 


I .0421 


10.90 


1 .0486 


12. s8 


1.0551 


14.28 


I .0616 


15-97 


I. 0681 


17.67 


1 .0746 


19-37 


I .0422 


10.92 


1 1.0487 


12.61 


1.0552 


14-30 


I .0617 


16.00 


1.0682 


17.69 


I. 0747 


19-39 


I .0423 


10.9s 


1.04S8 


12.64 


1.0553 


14-33 


I. 0618 


16.02 


1.0683 


17.72 


I .0748 


19.42 


I .0424 


10.97 


I .0489 


12.66 


I.OSS4 


14-35 


I .0619 


16.05 


I .0684 


17.75 


1.0749 


19.44 


I .0425 


II .00 


I .0490 


12 .69 


1.055s 


14-38 


I .0620 


16.07 


1.0685 


17.77 


1.0750 


19.47 


I .0426 


11.03 


1-0491 


12.71 


1.0556 


14-41 


1.0621 


i6. 10 


I .0686 


17.80 


I .0751 


19.50 


I .0427 


11.05 


I .0492 


12.74 


I. 0557 


14-43 


I .0622 


16.13 


1.0687 


17.83 


1.0752 


19.52 


I .0428 


11.08 


1 -0493 


12-77 


1-0S58 


14.46 


1.0623 


16. IS 


1.06S8 


J7.85 


1.0753 


19.55 


I .0429 


II . to 


1-0494 


12.79 


I-OS59 


14.48 


I .0624 


16.18 


I .0689 


17.88 


1.0754 


19.58 


I .0430 


II. 13 


1-0495 


12. 82 


I .0560 


14-51 


1.0625 


16. 21 


, I .0690 


17.90 


1-07SS 


19. 60 


I .0431 


II. 15 


I . 0496 


12.84 


I -0561 


14-54 


I .0626 


16.23 


I I .o6gi 


17.93 


1.0756 


19.63 


I .0432 


II. 18 


1 -0497 


12.87 


I .0562 


14-56 


I .0627 


16. 26 


I .0692 


17.95 


1.0757 


19.65 


I .0433 


II . 21 


I .0498 


12. 90 


1-0563 


14-59 


1.0628 


16.28 


I .0693 


17.98 


1.0758 


19.68 


1-0434 


II . 23 


1.0499 


12.92 


I .0564 


14.61 


I .0629 


16.31 


I -0694 


18.01 


I .0759 


19.71 


1 .0435 


II . 26 


I .0500 


12.95 


1.056s 


14.64 


I .0630 


16.33 


1 .0695 


18.03 


I .0760 


19.73 


I .0436 


11.28 


1.0501 


12.97 


I .0566 


14-67 


, 1.0631 


16.36 


I .0696 


18.0b 


I .0761 


19.76 


I -0437 


II. 31 


I .0502 


13-00 


1.0567 


14.69 


1.0632 


16.39 


I .0697 


18. oS 


I .0762 


19.79 


I .0438 


II .34 


1.0503 


13-03 


1.0568 


14.72 


1.0633 


16.41 


I .0698 


18. II 


1.0763 


19. Si 


1.0439 


II .36 


I .0504 


13-05 


I .0569 


14.74 


1 I .0634 


16.44 


I .0699 


18.14 


I .0764 


19.84 


1 . 0440 


11 -39 


1.0505 


13.08 ] 1.0570 


14.77 


1.063s 


16.47 


I .0700 


18.16 


1.0765 


19. 86 


I .0441 


II .42 


I .0506 


13. ic 


1 1-0571 


14. So 


; I .0636 


16.49 


I .0701 


1S.19 


I .0766 


19.89 


I .0442 


11-44 


1-0507 


13.13 


1 1-0572 


14.82 


i 1.0637 


16.52 


I .0702 


18.22 


1.0767 


19.92 


I .0443 


11.47 


I .0508 


13-16 


1-0573 


14.85 


1.0638 


16.54 


I .0703 


18.24 


I .0768 


19.04 


1 . 0444 


11-49 


1-0509 


13.18 


1 I-OS74 


14.87 


i 1.0639 

1 


16. 57 


I .0704 


18.27 


1 .0709 


19.97 


I -0445 


11-52 


I .0510 


13.21 


1 

j 1-0575 


14.90 


1 .0640 


16.60 


1-0705 


18.30 


1.0770 


20.00 


I . 0446 


11-55 


1.0511 


13-23 


1 1.0576 


14.93 


1 I .0641 


16.62 


I .0706 


18.32 


1-0771 


20.02 


1.0447 


11-57 


1 .0512 


13.26 


i 1-OS77 


14.95 


I .0642 


16.65 


1.0707 


1S.35 


1.0772 


20.0s 


I .0448 


II .60 


1-0513 


13.29 


1 1-0578 


14.98 


1.0643 


16.68 


I .070S 


18.37 


1-0773 


20.07 


1.0449 


1 1 . 62 


1-0514 


13.31 


1-0579 


15.00 


I .0644 


16.70 


I .0709 


18.40 


1.0774 


20. 10 


I .0450 


II .65 


1-051S 


13.34 


I -0580 


IS. 03 


1 .0645 


16-73 


I .0710 


18.43 


1-077S 


20. 12 


I .0451 


11.68 


1 -0516 


13.36 


1 -0581 


15-06 


I .0646 


16.7s 


I .0711 


18.4s 


1-0776 


20.15 


I .0452 


II . 70 


1-0517 


13.39 


1.0582 


15.08 


I .0647 


16.78 


I .0712 


1S.48 


1.0777 


20.18 


I -0453 


11-73 


1 .0518 


13.42 


1 1.0583 


15-11 


I .0648 


16.80 


1.0713 


18.50 


1.0778 


20. 20 


I .0454 


11.75 


1.0519 


13.44 


I I .0584 


15-14 


1 . 0649 


16.83 


I. 0714 


18.53 


1-0779 


20. 23 



.ALCOHOLIC BEl^ER^GES. 
EXTRACT IN WINE— {Continued) . 



699 



Specific 
Gravity. 



Ex- 
tract. 



1 .0780 1 20 . 26 

1 .0781 I 20. 28 

1 .0782 ! 20.31 

1.0783 20.34 

1 .0784 1 20. 36 



1.078s 
I .0786 
1.0787 

1 .0788 

1 .0789 

1 .0790 

1 .0791 

1 .0792 
I -0793 
1.0794 

1.079S 

1 .0796 

1 .0797 

1 .0798 
1.0799 

1 .0800 

1 .0801 

1 .0802 

1 .0803 



20 . 39 
20 .41 
20.44 
20.47 
20.49 

20.52 
20. 55 
20. 57 
20 . 60 
20.62 

20.65 
20.68 
20 . 70 
20.73 
20.75 

20. 78 
20.81 
20.8 s 
20.86 



I .0804 I 20.89 



I .0805 
1.0806 
I .0807 



I .0809 

I .o8to 
i.oSti 
I .0812 
1 . oS I 3 
1 .0814 



20.91 
20.94 
20.96 

20 .99 
21 .02 

21 .04 
21 .07 
21 . 10 

21 . I J 

21 . 15 



1 .0815 I 21.17 

1 .0816 I 21 . 20 

1 .0817 I 21.23 
I .08 I 8 ' 21 . 25 
1 .0S19 ^ 21 . 28 



1 .0820 

1 .0821 

1 .0822 

1 .0823 
I .0824 



21 .31 

21-33 

21 .36 
21.38 
21 .41 



1.0825 21.44 
I .0826 21 .46 
I .0827 21 .49 
I .0828 j 21.52 
I .0829 I 21 . 54 



I .0830 
I .0S31 

I .0S32 

1 .0833 

1 .0834 

1-0835 
1.0836 
1.0837 
1.0838 
I .0839 



21.57 

21 -59 
21 .62 
21 .65 
21 .67 

21 . 70 
21-73 
21-75 
21.78 
21 .80 



Specific ' Ex- 
Gravity. I tract. 



1 .0845 

1 .0846 

1 .0847 
1.0848 

1 .0849 

1 .0850 

1. 0851 
1.0852 
1-0853 
1.0854 

1-0855 
1.0856 
1.0857 
1.0858 
1-0859 

I .0860 
i.o86i 
1.0862 
1.0863 
r .0864 

.0865 
.0866 

~'7 



21 


96 


21 


99 


22 


02 


22 


04 


22 


07 


22 


09 



1 .0840 21 .83 

1. 0841 21.86 

1.0842 ' 21.88 

1 .0843 j 31 .91 j 

1 .0844 21 .94 



22.12 
22.15 
22.17 
2 2. 20 

22. 22 

22.25 
22 . 28 
22.30 
22.33 

22.36 
22.38 
22 .41 
22.43 
22.46 

22 .49 
22.51 
22.54 



,0868 1 22.57 
.0869 22.59 



.0870 
.0871 
.0872 
■ 0873 
,0874 

.0875 
,0876 
,0877 
0878 
0879 



.0881 
.0882 
.0883 
.0884 

.0885 
.0886 
.0887 
.0888 
.0889 

.0890 
.0891 
.0892 

.0893 

,0894 

0895 
0896 

o89'7 
0898 
0899 

0900 
0901 
0902 
0903 
0904 

0905 
0906 
0907 
0908 
0909 



22.62 
22.65 
22.67 
22 . 70 
22.72 

22.75 
22.78 
22.80 
22.83 
22.86 



22 . gi 
22-93 
22 .96 
22.99 

23-01 
23.04 
23.07 
23.09 
23. 12 

23-14 
23.17 
23.20 

23. 22 
23.25 

23.28 
23-30 



Specific Ex- 
Gravity. 1 tract. 



1 .0910 

1 .0911 

1 .0912 
1-0913 
1 -0914 

1.091S 

1 .0916 

1 .0917 

1 .0918 

1 .0919 

1 .0920 

1 .0921 

1 .0922 
1.0923 
I .0924 

1.0925 

1 .0926 

1 .0927 

1 .0928 

1 .0929 



23.67 
23.70 
23.72 
23.75 
23.77 

23.80 
23.83 
23.85 
23.88 
23.91 

23.93 
23.96 
23.99 
24.01 
24.04 

24.07 
24.09 
24. 12 
24.14 
24.17 



1.0930 24.20 

1 .0931 24. 22 

1.0932 24.25 

1.0933 24.27 

1.0934 24.30 



23 


h '■ 


23 


■ 3=; 


23 


38, 


23 


41 


23 


43 


23 


46 


23 


49 


23 


SI 


23 


54 


23 


57 


23 


59 


23 


62 


23 


6S 



1-0935 
I -0936 
1-0937 
1-0938 
1-0939 

1 . 0940 

1 .0941 

1 .0942 
1.0943 

1 . 0944 

1 .0945 

1 .0946 
1.0947 

1 .0948 

1 .0949 

1-0950 
1.0951 
1.0952 
1-0953 
1.0954 

1.0955 
1.0956 
1.09S7 

1 .0958 

1. 0959 

1 .0960 

1 .0961 

1 .0962 

1 .0963 

1 .0964 

1.0965 

1 .0966 

1 .0967 

1 .0968 

1 .0969 

1 .0970 

1 .0971 

1 .0972 
I .0673 
1.0974 



Specific 
Gravity. 



24.33 
24.35 
24.38 
24.41 
24.43 

24.46 
24.49 
24-Si 
24.54 
24-57 

24-59 
24.62 
24.64 
24-67 
24-70 

24.72 
24-75 
24.78 
24.80 
24.83 

24.8s 
24.88 
24.91 
24.93 
24.96 

24.99 

25.01 
25-04 

25.07 



25 


09 


2 5 


12 


25 


14 


2 5 


17 


25 


20 


25 


22 


25 


25 


25 


28 


25 


30 


25 


33 


25 


36 



1-0975 

I .0976 

1-0977 
1 .0978 
1.0979 

1 .0980 

1 .0981 

1 .0982 
1.0983 
1 .0984 

1.0985 

1 .0986 

1 .0987 

1.0988 

1 . 0989 

1 .0990 

1 .0991 

1 .0992 

1.0993 
1.0994 

1-0995 
I .0996 
1.0997 
1 .0998 

1.0999 

1 . 1000 

1 . 1001 

1 . 1002 

1.1003 
1 . 1004 

i.ioos 

1 . 1006 

1 . 1007 

1 . 1008 

1 . 1009 

1 . 1010 

1 . 101 1 

1 . 101 2 
I.IOI3 

1 . 1014 

1. 1015 

1 . ioi6 
I . 1017 
1 . 1018 

1 . 1019 

1 . 1020 

1 . 1021 
1.1022 

1 . 1023 

1 . 1024 

1.1025 

1 . 1026 

1 . 1027 

1 . 1028 
1 . 1029 

1 .1030 

1 .1031 

1 . 1032 
1.1033 

1 .1034 

1 . 1035 

1 .1036 
1.1037 

1 .1038 

1 .1039 



Ex- 
tract. 



2S.38 
25.41 
25.43 
25.46 
25.49 

25-51 
25.54 
25.56 
25.59 
25.62 

25.64 
25.67 
25-70 
25-72 
25-75 

25-78 
25.80 
25.83 
25.85 
25.88 

25.91 
25.93 
25.96 
25.99 
26.01 

26 . 04 
26.06 
26.09 
26.12 
26. 14 

26. 17 
26. 20 
26. 22 
26.25 
26. 27 

26.30 
26.33 
26.35 
26.38 
26.41 

26.43 
26.46 
26.49 
26.51 
26.54 

26.56 
26.59 
26.62 
26.64 
26.67 

26. 70 
26. 72 
26.75 
26.78 
26.80 

26.83 
26.85 
26.88 
26.91 
26.93 

26 .96 
26.99 
27.01 
27.04 
27.07 



Specific 
Gravity. 



1 . 1040 

1 .1041 

1 . 1042 

1. 1043 

1 . 1044 

1.104s 
1 . 1046 
1.1047 

1 . 1048 

1 . 1049 

1. 1050 
1.1051 
1. 1052 
1.10S3 
I.IOS4 

1-1055 
I - 1056 
I.IOS7 
1-1058 
1.1059 

I . 1060 
1 . 1061 

1 . 1062 

1. 1063 

1 . 1064 

1.106s 

1 . 1066 

1 . 1067 

1 .1068 

1 . 1069 

1 . 1070 

1 . 1071 

1 . 1072 

1. 1073 
1.1074 

1.1075 
I . 1076 
1.1077 

1 . 1078 

1 . 1079 

1 . 1080 

1 . 1081 

1 . 1082 
1.1083 
1 . 1084 

1.108s 

1. 1086 

1 . 1087 
1.1088 

1 . 1089 

1 . 1090 

1 . 1091 

1 . 1092 
1.1093 
1 . 1094 

1.1095 

1 . 1096 

1 .1097 

1 .1098 

1 . 1099 

1 . 1 100 

1 . 1101 

1 . 1102 

1 . 1103 
1 . 1104 



Ex- 
tract. 



27.09 
27 . 12 
27-iS 
27-17 
27 . 20 

27 . 22 
27.25 
27 . 27 
27-30 
27-33 

27-35 
27.38 
27.41 
27.43 
27.46 

27.49 
27.51 
27.54 
27-57 
27.59 

27 .62 
27.65 
27 .67 
27 . 70 
27 . 72 

27.75 
27.78 
27.80 
27-83 
27.86 

27.88 
27.96 
27-93 
27 .96 
27.99 

28.01 
28.04 
28.07 
28.09 
28.12 

28.15 
28.17 
28. 20 
28. 22 
28.25 

28.28 
28.30 
28.33 
28.36 
28.38 

28.41 
28.43 
28.46 
28.49 
28.51 

28.54 
28.57 
28.59 
28.62 
28.65 

28.67 
28. 70 
28.73 
28.75 
28.78 



Specific 
Gravity. 



1 .1105 

1 . 1106 

1 . 1107 

1 . 1 108 
I . H09 

1 . mo 
1 . nil 
1 . Ill 2 
1 . 1 1 1 3 
1 . 1114 

1 .1115 
1 . 1 n6 
I . n 17 
1.1118 
1 . 1119 

1 . 1120 

1.1121 
I.II22 
1.1123 
I . II24 

1.II2S 
I . 1126 
1.1127 
I. 1128 
I . II29 

1.1130 
1 . 1 1 3 1 
I -1132 
I-II33 
I -II 34 

I-II3S 
1-1136 
1.1137 
I-I138 
1.1139 

1 . 1 1 40 

1 . 1141 

1 . 1142 
1.1143 
1.1144 

1.1145 
1 . 1146 
1.1147 
1 . 1 148 
1.1149 

1 .1150 
I .1151 
1.1152 
1-II53 
1.1154 

I-II55 
1-1156 
I-1I57 
1-1158 
I. 1159 



Ex- 
tract. 



28.81 
28.83 
28.86 
28.88 
28.91 

28.94 
28.96 
28.99 
20 . 02 
29.04 

29.07 
29 . 09 
29.12 
29.15 
29.17 

29 . 20 
29.23 
29. 25 
29. 28 
29-3t 

29-33 
29.36 
29-39 
29.41 
29.44 

29.47 
29.49 
29.52 
29-54 
29.57 

29. 60 
29 . 62 
29.65 
29.68 
29. 70 

29 -73 
29. 76 
29. 7S 
29.81 
29. S3 

29.86 
29.89 
29.91 
29.94 
29 .96 

29 .99 

30.02 
30.04 
30.07 
30. 10 

30.13 
30. I. > 
30.18 
30.21 
30.23 



yoo 



l^OOl) INSPECTION AND ANALYSIS. 




Fig. 114.— Apparatus for Determining Volatile Acids in Wine. 




Imc. U.S.— Horlvct'sApimraluslor Dj^Utih iniiifr ih,. Volalilc Ac ids in 



Wine. 



ALCOHOLIC BEVERAGES. 70T 

as an indicator. Each cubic centimeter of tenth-normal alkah is equiv- 
alent to 0.006 gram acetic acid. 

Hortvet Method* — The apparatus (Tig. 115; consists of a 300 cc. 
flask into the neck of which is fitted a 200-cc. cylindrical flask, with a 
steam tube, a bulb-trap leading to a condenser, and a stop-cock funnel. 
The procedure is as follows: Pour 150 cc. of recently boiled water into 
the larger flask, attach the smaller flask by means of a section of rubber 
tubing, run in 10 cc. of wine (previously freed from carbonic acid;, 
close the stop-cock and boil. In extreme cases arid to the wine a small 
piece of paraffin to pre\'ent foaming. When the water has boiled a 
moment, close the tube at the .side of the larger flask and distil until 
70 cc. of distillate have pa.ssed over. Transfer to a beaker, without 
discontinuing the distillation, and titrate, using phenolphthalein as 
indicator. Continue the distillation until the last 10 cc. [xjrtion requires 
not more than one drop of tenth-normal alkali for neutralization. 
Usually 80 or 90 cc. of distillate includes practically all of the volatile 
acids. Cool the apparatus, thus allowing the wine residue to be drawn 
back into the lower flask, rinse with boiled water, and reserve the total 
liquid for determination of non-volatile acids. 

Non-volatile Acids. — ^These may be determined by difference, cal- 
culating the vola'.ile acids for purposes of subtraction in terms of '.ar- 
taric or other acid in which the total acidity is expressed. Non- volatile 
acid may be directly determined by evaporating to dr\'ness a measured 
portion of the liquor, boiling the residue with water, and titrating the 
solution with the standard alkali. 

Detection of Free Tartaric Acid. — Nessler's Method. — Some pov;- 
dered cream of tartar h added to a portion of the wine in a corked flask, 
which is shaken from time to time, and the liquid finally filtered. To 
the filtrate is added a little 20% potassium acetate .solution. If free 
tartaric acid is present, on stirring and especially after standing for some 
time, there will be a precipitate of cream of tartar. 

Determination of Tartaric Acid, Total, Free, and Combined. — Pro- 
visional methods A. O. A. C.f 

Total Tartaric Acid. — To 100 cc. of wine add 2 cc. of glacial acetic 
acid, 3 drops of a 2o9c solution of potassium acetate, and 15 grams of 
powdered potassium chloride, and stir to hasten solution. Add 15 cc. 
of 9596 alcohol Tspecific gravity 0.81) and rub the side of the beaker 
vifforouslv with a glahs rod for about one minute to start cr\^slallization. 

* Jour. Ind. Eng. Chem., i, 1909, p. 31 

t U. S. Dept. of .-Vgric, Bur. of Chem., Bui. 65, p. 87. 



702 FOOD INSnr.CTION /fNl) ANALYSIS. 

Let stand at least fifteen hours at room temperature; decant the n(|uid 
from the separated acid potassium tartrate as rajjidly as possible (using 
vacuum) through a (looch crucible [)repared with a very thin film of 
asbestos, transferring no more of llic prc( i;)ila(e to the crucible than 
necessary. Wash the precijjilale and filter tpree times wi;h a small 
amount of a mixture of 15 grams potassium chloride, 20 cc. of 95% alco 
hoi (specific gravity 0.81), and 100 cc. water, using not more than 20 cc. 
of the wash solution in all. Transfer the asbestos film and j)rccij)itate 
to the beaker in which I Ik- precii)itation took place, wash oul the Gooch 
crucible with hot water, add about 50 vc. of hot water, heat to boiling, 
and tilrale the hoi solution with decinormal sodium hydroxide, using 
delicate litmus tincture or litmus paper as indicaior. Increase ihe 
number of cubic centimeters of decinormal alkali emj)loycd by 1.5 on 
account of the solubility of the precijMtate. This figure mul;if)lied by 
0.015 gives the amount of total tartaric acid in grams per jog cc. 

Cream oj Tartar. — Ignite the residue obtained from the eva])oration 
of 50 cc. of wine as directed under the determination of ash. Exhaust 
the ash with hot water, add to the filtrate 25 cc. of decinormal hydro- 
chloric acid, heal to incipient Ijoiling, and titrate with decinormal alkali 
solution, using litmus as indicator. Deduct from 25 c c. the number 
of cubic centimeters of decinormal alkali employed, and multiply the 
remainder by 0.0188 for potassium bitartrale expressed in grams. 

Free Tartaric Acid. — Add 25 cc. of decinormal hydrochloric acid to 
the ash of 50 cc. of wine, heat to incipient boiling, and titrate with deci- 
normal sodium hydroxide, using litmus as indicator. Deduct the number 
of cubic centimeters of alkali employed from 25, and multiply the 
remainder by 0.0075 to obtain the amount of tartaric acid necessary 
to combine with all the ash (considering it to ccmsist entirely of potash). 
Deduct the liguiX' so obtained from the total tartaric acid for the free 
tartaric acid. 

Determination of Free and Combined Malic Acid in Cider and Wine. 
— Evai)orate 100 cc. of the samj)le on the water bath lo half its \()lume, 
cool, and treat hrst with 10 cc. of 10% calcium chloride solution, and 
then with ammonia to strong alkaline reaction. Let stand for an hour 
and filter. This removes the tartaric acid. Concentrate the filtrate 
by evaporation on the water-bath to 25 cc, add 75 cc. of g^% alcohol, 
heat to the boiling-point, and fiher. Wash the residue with a mixture of 
3 parts 95% alcohol and 1 i)art water, dry, and burn to an ash. Add 
25 cc. of tenth-normal hydrochloric acid lo the ash, dilute with water, 



/ILCOHOUC BEyERAGES. 703 

hcut to boiling, and lilratc with lenlh-normal sodium hydroxide, using 
[)hcn()lphlhalcin as an indicator. Multiply the difference between 25 
and the number of cubic centimeters required to neutralize by 0.0067 
for the grams of malic acid. 

Polarization. — Results are usually expressed m terms of the undiluted 
product. The simplest method consists in treating a measured amount 
of wine or cider with one-tenth of its volume c>f learl subacetate, filtering, 
and polarizing the filtrate in the 200-mm. tube. 'Vhv. narh'ng is in( n^ased 
by 10% for the true direct polarization. If the filtrate is deej^ly (olorerl 
after clarification with subacetate, as in the case of some artificially colorerl 
wines, use a loo-mm. tube and multiply by 2 the reading, increaserl by 10%. 

If the reducing sugars arc also to be determined, one can use the same 
solution for both the j)olarization and the reducing sugars, as follows: 

Exactly neutralize with sodium hydroxide solution a measured quan- 
tity of the wine, using litmus pajjcr as an indicator, and eva[)orate on the 
water-bath to about one-fourth its original volume. Wash with water, 
into the measuring-glass, add enough subacetate of lead solution to 
clarify, and make up with water to the original volume. FiUer, and lo 
a measured amount of the filtrate adfl lo'^^^^ of its volume of a saturated 
solution of sodium suljjhate. Again filter and submit to [jolarization a 
portion of the filtrate, making the 10% correction on the reading. 

If the invert reading is desired, subject a jjortion c;f the filtrate 'to 
inversion as described under Sugars. 

Determination of Reducing Sugar. — Determine the reducing sugar as 
dextrose by the Defren or the Allihn methofl. For this [)urpose dilute a 
portion of the wine, dealcoholized and clarified as described in the pre- 
ceding section, so that it contains about one-half of 1% of sugar for the 
Defren and about 1% of sugar for the Allihn method. One may assume 
2% as the sugar-free extract of wine, the number of volumes of water to 
be added to the filtrate being determined by the difference between 2 
and the total extract as determined. 

Determination of Glycerin. — Evaf;orate 100 cc. of the wine on the 
water-bath to a vcjlume of about 10 cc, after which i (jr 2 grams of fine 
sand are added and sufficient milk of lime io render alkaline. C'onlin'ie 
the evaporation nearly to dryness, and after cooling shake with 50 cc. (;f 
95% alcohol, heat to boiling on the water-bath, and filter. Wash the 
insoluble residue on the filter-paper with several portions of hf;t ah ohol, 
using say 100 cc, adding the washings to the cjriginal filtrate. lua|>orate 
the alcoholic filtrate to a syruj^y consistency on the water-bath, dissolve 



704 FOOD INSPECTION AND ANALYSIS. 

the residue in lo cc. of absolute alcohol, and transfer to a flask with 15 cc. 
of ether. Tightly cork the flask, shake, and allow to stand for some time. 
Then filter into a tared dish, wash with a mixture of absolute alcohol (i 
part) and ether (1.5 parts), evaporate the filtrate to syrupy consistency on 
the water-bath, dr}- in a water-oven for one hour, and weigh as glycerin. 

With plastered wines the results are too high, for the reason that the 
potassium sulphate present is decomposed by the lime to form potassium 
hydroxide, soluble in glycerin and alcohol. In such wines the above 
residue sho"Jd be ignited, and the ash deducted from the first weight. 

Determination of Potassium Sulphate. — Acidify 100 cc. of the sample 
with hydrochloric acid, heat to boiling, and add an excess of barium 
chloride solution. Filter, wash, dr}-, ignite, and weigh as barium sul- 
phate, calculating the equivalent of potassium sulphate. The presence 
of the latter in excess of 0.06 gram per 100 cc. indicates plastering. 

Determination of Tannin. — An approximate method of determining 
tannin is that of Nessler and Barth. 12 cc. of wine are treated \\ith 30 
cc. of alcohol and filtered. 35 cc. of the filtrate, which corresponds to 
10 cc. of the wine, is evaporated to about 6 cc. and transferred to a lo-cc. 
graduated centrifuge tube. A few drops of 40% sodium acetate are 
then added, and a slight excess of 10% ferric chloride. The tube is 
corked, gently agitated, and allowed to stand for twenty-four hours. The 
volume of the precipitate is then measured, each cubic centimeter being 
•equivalent to o.o33'^( of tannin in the wine. 

Foreign Coloring Matters in Wine. — A wide variety of artificial colors 
have been found in red wine. Those most commonly employed at present 
are cochineal, fuchsin, and acid fuchsin. 

The Pharmacopoeia prescribes the following color tests: 

If 2 cc. of red ^^'ine be mixed in a test-tube with 2 drops of chloroform 
and 4 cc. of normal potassium hydroxide, and the mixture carefully 
heated, the disagreeable odor of isonitril should not become preceptible 
(absence of various anilin colors). 

If 50 cc. of red wine be treated with a slight excess of ammonia water, 
the liquid should acquire a green or bro%Miish-green color; if it be then 
well shaken with 25 cc. of ether, the greater portion of the ethereal layer 
removed and evaporated in a porcelain capsule with an excess of acetic 
acid and a few fibers of uncolored silk, the latter should not acquire a 
crimson or violet color (absence of fuchsin). 

If 25 cc. of red wine heated to about 45° C. be well agitated \\'ith 25 
grams of manganese dioxide, the liquid filtered oft" and acidulated with 



ALCOHOLIC BEyERAGES. 705 

hydrochloric acid, it should not acquire a red color (absence of sulpho- 
fuchsin). 

Dupre's Method of Detection* — Small cubes of jelly measuring about 
2 cm. in thickness are prepared as follows: Dissolve i part of pure 
gelatin in 10 parts boiling water and pour upon a plate to harden. This 
is then cut into cubes of the above size by a sharp knife. When a wine 
is suspected of containing foreign color, one of the cubes is immersed 
therein and allowed to remain for twenty-four hours, after which it is 
removed, washed slightly in cold water, and cut through with a knife. If 
the color is a natural one, it will lightly tinge the outer surface of the 
cube, but will not permeate far below the surface, so that the inner por- 
tion of the cross-section will be largely free from color. Nearly all foreign 
coloring matters used in wine, such as most coal-tar dyes, cochineal, 
Brazil wood, logwood, etc., will be found to deeply permeate the jelly 
cube often to the center. Information as to the nature of the color may 
sometimes be gained by immersing the dyed jelly cube in weak ammonia. 
If the color be rosanilin, the cube is decolorized, if cochineal, a purple 
coloration will result, and if logwood, a brown tinge. 

Cazeneuve's Methods for Detecting Colors in Wine. — While by no 
means complete, the following method of Cazeneuve as condensed and 
arranged by Gautier {La Sophistication des Vins) will often be found 
helpful. If other colors than these are evidently present, tests should 
be made as indicated in Chapter XVII. Cazeneuve employs the fol- 
lowing reagents: 

(i) Yellow oxide of mercury, finely pulverized. 

(2) Lead hydrate, freshly precipitated, well washed, suspended in 
about twice its volume of water; to be kept in a stoppered bottle; should 
be renewed after several days' use. 

(3) Gelatinous ferric hydrate, well washed from ammonia, suspended 
in about twice its volume of water. 

(4) Manganese dioxide, pulverized. 

(5) Concentrated, chemically pure sulphuric acid. 

(6) White wool. 

(7) Stannous hydrate, freshly precipitated, well washed, suspended in 
water, and kept from exposure to light and air. 

(8) Collodion silk, the artificial silk produced from nitro-cellulose. 
This fiber has a special affinity for basic dyes. 

* Jour. Chem. Soc, 37, p. 572. 



7o6 



FOOD INSPECTION AND ANALYSIS. 



To lo cc. of the wine are added 0.2 gram finely powdered yellow oxide of mercury. 
Boil and pour upon a double filter. 



Filtrate colored either before or after acidifying. 



(5, ^ 






Filtrate colored yellow. 10 cc. 
of the wine are warmed with 2 
grams lead hydrate. Filter. 



Filtrate colored yellow. 
A large excess of lead 
hydrate is added and 
the liquid is boiled. 



Filtrate colored red. 10 
cc. of the wine are treated 
with 2 grams lead hydrate 
and filtered. 



Filtrate col- 
orless a f t e I 
acidifying. 




ALCOHOLIC BEVERAGES. 707 



MALT LIQUORS. BEER. 



In its widest sense beer may be defined as the product of fermentation 
of an infusion of almost any farinaceous grain with various bitter extract- 
ives, but unless otherwise qualified it should be strictly applied to the 
beverage resulting from the fermentation of malted barley and hops. 
In the manufacture of beer two distinct processes are employed, viz., 
malting or sprouting the grain, and brewing. IMany brewers do noth- 
ing but the latter, buying their malt already prepared. 

Malting. — For the preparation of malt, the barley is steeped in water 
for several days, after which the water is drained off and the moist grain 
is "couched," or piled in heaps, on a cement floor, where it undergoes a 
spontaneous heating process, during which it germinates, forming the 
ferment diastase. When the maximum amount of diastase has been 
produced, indicated by the length of growth of the sprout, or "acrospire " 
within the grain, the germination is checked by spreading the grain in 
layers over a perforated iron floor, and finally subjecting it to artificial 
heat. The character of the malt and of the beer produced from it depends 
largely on the heat at which the "green" malt is kiln dried. If dried 
between 32° and 37° C. it forms pale malt, which produces the hghtest 
grades of beer. Most beer is made from malt dried at higher tem- 
peratures, say from 38° to 50°, the depth of color of the liquor varying 
with the heat to which the malt has been subjected, while the color of the 
malt varies from the "pale" through the "amber" to "brown," or even 
black. The darkest grades are sometimes dried at temperatures over 
100° C, even to the point where the starch becomes caramelized. 

A more modem method consists in the so-called pneumatic malting, 
wherein the whole operation is conducted in a large rotating drum, which 
holds the grain, and in which the temperature and moisture at different 
stages is carefully controlled by the admission to the interior of the drum 
of moisture-laden or dry air, heated to the required degree. 

The chief object of malting is the production of diastase, which by 
its subsequent action on the starch converts it into the fermentable sugars 
maltose and dextrin. Malt contains much more diastase than is necessary 
to convert the starch simply contained therein to maltose, and is capable 
of acting on the starch of a considerable quantity of raw grain, such 
as com or rice, when mixed with it. This practice of using other grains 
than malt is prohibited in some localities, such as Bavaria. 



7q8 food inspection and analysis. 

Brewing. — The malt, or mixture of malt and raw grain, is first crushed 
and "mashed" by stirring with water in tubs at 50° to 60° C, finally 
heating to 70°. During this process the conversion of the starch to mal- 
tose and dextrin takes place. The resulting liquor is known as "wort," 
containing, besides maltose and dextrin, peptones and amides. The 
clear wort is then drawn off from the residue, and boiled to concentrate 
the product and to sterilize it, after which hops (the female flower of 
the Humulus lupuliis) are added and the boiling continued. Hops 
contain resins, bitter principles, tannic acid, and a pecuUar essential oil, 
all of which are to some extent imparted to the wort. After coohng and 
settling, the clear wort is run into fermenting-vats, where selected yeast, 
usually saccharomyces cerevisicE, is added, and the alcoholic fermentation 
allowed to proceed. The temperature greatly affects the character of 
the fermentation. If kept between 5° and 8° C, a slow fermentation 
proceeds, known as bottom fermentation, during which the yeast settles 
out at the bottom. This is much more easily controlled than the 
quick or top fermentation, which takes place at from 15° to 18°, much 
of the yeast in the latter case being carried to the surface, from which it 
is finally removed by skimming. In either case the yeast feeds upon 
the albuminous matter present. At the proper stage the beer is drawn off 
from the larger portion of the yeast, and nm into casks, or tuns, in which 
an after-fermentation proceeds. The beer is finally clarified by treatment 
with gelatin or beech shavings or chips, to which the floating yeast-cells 
and other impurities attach themselves. It is finally stored in barrels 
coated with brewers' pitch, or pasteurized at 60° C. and bottled. 

Varieties of Beer. — Formerly the division of beers into "lager," 
"schenk," and "bock" was made by reason of the fact that beer had to 
be brewed under certain cHmatic conditions and at certain seasons only. 
Now, with improved means for artificial refrigeration, and \\'ith better 
methods controlling all stages of the process, these distinctions are less 
marked. 

Lager Beer (from lager, a storehouse) is a term originally applied to 
Bavarian beer, but is now given to any beer that has been stored several 
months. Formerly lager beer was made early in the winter, and stored 
in cool cellars till the following spring or summer, during nearly all of 
which time a slow after-fermentation took place. The best lager beers 
contain a low proportion of hops, and are high in extract and 
alcohol. 

Schenk Beer is a quickly fermented beer made in winter for immedi- 



ALCOHOLIC BE^ER^GES. 705 

ate use. It is brewed in from four to six weeks and will not keep long 
without souring. 

Bock Beer, according to older systems of nomenclature, occupied a 
middle place between lager and schenk, being an extra strong beer brewed 
for spring use and made in limited quantities, not being intended for 
storage. 

Berlin Weiss Bier is prepared by the quick or top fermentation of a 
wort consisting of a mixture of malted barley and wheat with hops. It is 
high in carbon dioxide, being usually bottled before the second fermen- 
tation has ended. 

Ale is \-irtually the English name for beer. It is usually lighter colored 
than lager beer, being made from pale malt by quick or top fermentation, 
and containing rather more hops than beer. It has a high content of 
sugar, due to checking fermentation at an earUer stage than in ordinary 
beer. 

Porter is a dark ale, the deep color of which should be due to the use 
of brown malt dried at a high temperature, but which is sometimes colored 
by the admixture of caramel. It has a large extract, chiefly sugar. 

Stout is an extra-strong porter, being high both in alcohol and extract. 

Composition of Beer. — Beer is a somewhat complex liquor. Besides 
water, alcohol, and sugar, it contains carbon dioxide, succinic acid, dex- 
trin, glycerin, tannic acid, the resinous bitter principles of hops, nitrog- 
enous bodies (chiefly peptones and amides), alkaline and lime salts 
(chiefly phosphates), fat (traces), acetic acid and laaic acid. The latter 
acid constitutes the chief fixed acid of beer. 

The following analyses of different varieties of beer are due to Konig: 






I < 



< I s- 



Schenk. 205 1.0114 91.11 0.197 3.36J5.34' 0.74 °-95 i-^i 0.1^60.12 0.2040.055 

Lager 258 i. 0162 90.08 0.196 3.93 5.79 0.71 0.88 3.730.1510.1650.2280.077 

Export beer.: 109 1.0176 89.01 0.209 4.40 6.38 0.74 1.20 3.47 o. 161 o.iS4 0-247 °-074 

Bock 84 X. 0213 87.87 0.2344.69 7.21' 0.73 1. 81 3.97 0.165 0.1760.2630.089 

Weiss bier.. 26 i. 0137 91.63 0.297 2.73 5.34' °-5* i.62i 2.42,0.3920.0920.1490.034 

Porter '40 1.0191 88.49 0.215 4.70 6.59 °-65 2.62' 3.08.0.281 0.3630.093 

Ale :;S r.0141 89.42 0.201 4.75 5.6;^ o.ti 1.C7 i.8i'o.278i 0.31 c.c>6 



Fifteen samples of lager beer and seven samples of pale ale, bought 
in Massachusetts bar-rooms, representing as nearly as possible the quality 



7IO 



FOOD iNSPECTlCN AK'D /IN A LYSIS. 



of liquor sold ever}' day to patrons by the bottle or glass, were analyzed 
by the Board of Health with the following results : 





Per Cent of 

Original Wort 

Extract. 


Per Cent of 

Alcohol bv 
Weight.' 


Per Cent of 
Extract. 




18.91 

7-33 
15.04 
15.99 
10.95 
13-56 


7.07 
1. 10 
4.45 
5-37 
3-53 
4-49 


7.76 




3-67 
5-92 
5-47 
3-3S 
4o4 


Mean 


Pale ale — Maximum 




Mean 



Five out of the 15 beer samples and 3 out of the 7 ale samples con- 
tained salicylic acid. 

The percentage composition of the ash of German beer is thus given 
by Konig as the mean of 19 analyses: 



Ash in 

100 Parts 

Beer. 


Potash. 


Soda. 


Lime. 


-Magnesia. 


Iron Phos- , Sul- 
Oxide. phoric phuric Silica. 
Acid. Acid. 


Chlorine, 


0.306 ! 33.67 


S.94 


2. 78 


6.24 0.48 31.35 3.47 9.29 


2.93 



Malt and Hop Substitutes. — By reason of the fluctuation in market 
price of these two chief constituents of beer, it sometimes becomes a 
question of economy to employ cheaper substitutes wholly or in part 
for one or the other. There are two classes of malt substitutes, (t) those 
which, like corn, rice, and wheat, are mixed directly with the malt before 
"mashing," and, like the malt, have to undergo a saccharous fermenta- 
tion before being acted on by yeast, and (2) such substances as cane 
sugar, invert sugar, commercial glucose, and dextrin, which are added 
to the wort at a later stage in the brewing, just before the addition of the 
yeast, being in condition to be readily acted on by the latter. 

Glucose is by far the most common malt substitute, by reason of the 
fact that its sugars much resemble those of malt, and are in readily ferment- 
able form. Diastase forms from the malt dextrin and maltose, while 
commercial glucose contains dextrin, maltose, and dextrose. 

When the price of malt is abnormally high, the addition of glucose 
is decidedly economical, but when ordinary conditions prevail, the cost 
of the two, figured vdih. reference to their yield in alcohol and extract, 
is about the same. Aside from the question of economy, however, there 
are advantages in the use of glucose, such as diminishing the nitrogenous 
content of the wort ^^'ithout lessening the alcohol or extract yielded. 



ALCOHOLIC BEVERAGES. 711 

The nitrogenous matter left after fermentation is one of the chief 
causes of cloudiness or turbidity in the finished product, and is some- 
times difficult to remove. By the use of glucose, especially in brewing 
clear bottled ales and sparkling pale beers, the appearance of the 
product is much enhanced. The temptation at times to add more 
glucose than is necessan,' to accomplish this is great. A high-grade malt 
may have as much as 40^ of glucose added to its wort and still produce 
an acceptable beer. With a low-grade malt, glucose yields a ver}^ poor 
quality of beer. Hence the use of glucose may or may not be desirable, 
though it can hardly be considered unqualifiedly as an adulterant. 

As to the employment of hop substitutes, the question of relative 
price again enters in. Only when the price of hops is high is there any 
special inducement to use substitutes. Quassia wood, chiretta, gentian, 
and calumba, all of which yield bitter principles, have been used in beer, 
and cannot be considered detrimental to health. Allen and Chattaway 
have found the first two in beer examined by them.* Such poisonous 
substances as cocculus indicus, picric acid, and strsxhnine are alleged to 
have been used as hop substitutes, but there is no authentic record of any 
of them having been found in recent years, if at all. 

Adulteration of Malt Liquors and Standards of Purity. — The Joint 
Committee on Standards of the A. O. A. C. and the A. S. X. F. D. D. has 
adopted the following standards: 

Malt Liquor is a beverage made by the alcoholic fermentation of 
an infusion, in potable water, of barley malt and hops, with or without 
unmalted grains or decorticated and degerminated grains. 

Beer is a malt hquor produced by bottom fermentation, and contains 
in 100 cc, at 20° C, not less than 5 grams of extractive matter and 
0.16 gram of ash, chiefly potassium phosphate, and not less than 2.25 
grams of alcohol. 

Lager Beer, Stored Beer, is beer which has been stored in casks for 
a period of at least three months, and contains, in 100 cc, at 20° C, 
not less than 5 grams of extractive matters, and 0.16 gram of ash, chiefly 
potassium phosphate, and not less than 2.50 grams of alcohol. 

Malted Beer is beer made of an infusion, in potable water, of barley, 
malt, and hops, and contains, in 100 cc, at 20° C, not less than 5 grams 
of extractive matter, nor less than 0.2 gram of ash, chiefly potassium 
phosphate, not less than 2.25 grams of alcohol, nor less than 0.4 gram 
of crude protein (nitrogen X 6.25). 

* Analyst, 12, 112. 



712 



FOOD INSPECTION /iND y4NALYSIS. 



Ale is a malt liquor produced by top fermentation, and contains, in 
ICO cc, at 20° C, not less than 2,75 grams of alcohol, nor less than 
5 grams of extract, and not less than 0.16 gram of ash, chiefly potassium 
phosphate. 

Porter and Stout are varieties of malt liquors made in part from 
highly roasted malt. 

Non-injurious bitter principles are no doubt employed in place of 
hops, and unless the liquor is sold for a pure malt beer, they cannot be 
regarded as adulterants. 

The tendency to shorten the time of storage of beer, or to sell it without 
storing at all, lessens or does away with the after-fermentation, resulting 
in a lack of "life" or effervescence in the product. This is sometimes 
made up by the addition of sodium bicarbonate. 

Distinction between Malted and Non-malted Liquors. — In some 
states where strict prohibitory liquor laws are in force, it is illegal to sell 
"malt liquors," so that when convictions are obtained, it is necessary 
for the analyst to distinguish between liquors brewed wholly or in part 
from malt and those in which no malt has been used, but which were 
brewed entirely from malt substitutes. This distinction is not always 
easy to make with precision. In the absence of malt, glucose is usually 
the sole source of alcohol in these beverages. Parsons * has shown that 
the most striking points of difference between malted and non-malted 
liquors are in their per cent of phosphoric acid and albuminoids, and that 
pure malt beer or ale should contain at least 0.04% P2O5, and 0.25% 
albuminoids (NX6.25). A low ash and high content of sulphates in 
the ash are also indicative of glucose. The following analyses made by 
Parsons clearly show these distinctions: 

COMPOSITION OF SEVENTY-SIX SAMPLES OF AMERICAN MALT LIQUORS. 





Specific 
Gravity. 


Alcohol 
by Vol- 
ume. 


Extract. 


Albumin- 
oids 
(NX6.25) 


Phos- 
phoric 
Acid. 


Ash. 


Sul- 
phates in 
Ash. 


Free 
Acid. 


Average 

Maximum 

Minimum. . . . 


I .0100 
I. 0210 
1.0047 


5-61 
7-85 
0-35 


4.61 
7.64 
3-15 


0.470 
0.614 
0.290 


0.061 
0.095 
0.045 


0.209 
0.296 
0.147 


6.34 
12.67 

2-44 


0.26 
0.87 

O.IO 



* Jour. Am. Chem. Soc, 24, 1902, p. 11 70. 



ALCOHOLIC BEVER/iGES. 713 

TYPICAL ANALYSES OF BEERS APPARENTLY NOT BREWED FROM MALT. 



Number. 


Specific 
Gravity. 


Alcohol 
by Vol- 
ume. 


Extract. 


Albumin- 
oids 
(NX6.2S) 


Phos- 
phoric 
Acid. 


Ash. 


Sul- 
phates. 


Free 
Acid. 


I 


1.0074 
I . 0098 
1.0062 
I.0112 
I. 0041 


1.68 
2.63 
2.27 
2. II 
1.85 


2.52 
3-40 
2.25 

3-53 
^•73 


0.114 
0.215 
0.150 

0-133 
0.031 


O.OIO 

0.023 
0.015 
0.015 

O.OIO 


0.19 

0.180 

0.124 

0.140 

0.088 


21.22 

11.30 
10.81 
12.50 


Normal 


2 


% 


,, 


4 


,, 


c 


<< 







The ash of the fifth sample is thus compared with that of the average 
beer as given by Blyth: 

Malt Beer " No-malt" Beer 

(Blyth). (Parsons). 

K2O 37-22 12.93 

NazO 8.04 19.61 

CaO 1.93 Undetermined 

MgO 5.51 

FeA Trace 

SO5 1.44 10.81 

P2O5 32.09 10.71 

CI 2.91 21.76 

SiOj 10.82 7.50 

Preservatives in Beer. — Antiseptics are frequently added to malt 
liquors, salicylic acid being most commonly used. Fluorides of ammo- 
nium and sodium have been found in American beer. Other preserva- 
tives to be looked for are benzoic acid and sulphites. Beer casks are 
frequently "sulphured" or fumed with a solution of calcium bisulphite, 
so that the beer may derive its content of sulpliites from this source. 

In cases of police seizure of beer sold in bulk or in opened bottles for 
the purpose of ascertaining whether or not their alcoholic content exceeds 
certain limits fixed by law, a little formalin had best be added as soon as 
possible after the seizure to prevent further fermentation. This is espe- 
cially desirable in cases where there is likely to be some delay in making 
the analysis, so as to forestall any claim on the part of the defendant of 
additional alcohol being formed after the seizure. From 6 to 8 drops of 
a 40% solution of formaldehyde to a quart of beer is sufficient, and this 
quantity will not appreciably affect the analysis. 

Arsenic in Beer. — In 1900 a very disastrous epidemic of arsenical 
poisoning occurred in Manchester, England, involving several thousand 
cases, many of which were fatal. The arsenic was traced to sulphuric 



714 FOOD INSPECTION /iND ANALYSIS. 

acidj which entered into the manufacture of commercial glucose used 
in the beer, the acid found so highly arsenical being made from a certain 
variety of Swedish pyrites, which was found to be abnormally high in 
arsenic. There appeared to be no doubt whatever that the beer was the 
sole cause of the trouble. While the presence of arsenic was in this case 
accidental, carelessness was shown on the part of those having to do with 
the purity of the materials entering into the composition of the beer. 
Fortunately no other instances are on record of arsenical poisoning from 
malted liquors. A large number of samples of American beer have been 
examined in the laboratory of the Food and Drug Department of the 
Massachusetts State Board of Health, and only insignificant traces of 
arsenic have in any case been found. 

Temperance Beers and Ales. — Many varieties of these so-called tem- 
perance drinks are home-made, as well as sold on the market. They are 
usually slightly fermented infusions of various roots and herbs, including 
ginger or sassafras, with molasses or sugar and yeast, and more often 
contain less than i% of alcohol by volume. Among them are included 
spruce beer, and the various root beers, such as ginger beer and ginger 
ale. The latter beverages are generally carbonated. Numerous brands 
of bottled beer are manufactured, which contain virtually the same body 
and characteristic flavor as lager beer, but not the alcohol. Indeed the com- 
position of many of these beverages is identical with that of lager beer, 
excepting in alcoholic content, being made by substantially the same 
process and out of the same ingredients, but with the alcohol finally 
removed by steaming, so that the liquor comes within the limits of a 
temperance beverage. Of this class is Uno beer, which ranges from 
0.6 to 0.9 per cent in alcohol. 

METHODS OF ANALYSIS OF MALT LIQUORS.* 

Preparation of Sample. — Transfer the contents of the bottle or 
bottles to a large flask and shake vigorously to hasten the escape of 
carbon dioxide, care being taken that the liquor is not below 15° C, 
smce below this temperature the carbon dioxide is retained by the beer 
and is liable to form bubbles in the pycnometer. 

Specific Gravity. — See page 657. 

Ash. — Determine in 25 cc. by evaporation and ignition at dull 
redness. 

* Barnard, U. S. Dept. of Agric, Bur. of Chera., Circ. 33. A. O. A. C. Methods, ibid., 
Bui. 107 (rev.), p. 90. 



ALCOHOLIC BEl^ERAGES. 



ns 



Determination of Alcohol. — From the Specific Gravity of the Dis- 
tillate. — Proceed as described on p. 658, employing 100 cc. of the liquor, 
and determining the specific gravity at 15.5° C. If the liquor is 
markedly acid, add o.i to 0.2 gram of precipitated calcium carbonate 
previous to distillation. 

From the Refraction of the Distillate. — Prepare the distillate as 
described on p. 658, except that it is made up to the mark at 17.5° C. 
Determine the refraction at 17.5° C. by means of the immersion refrac- 
tometer, and calculate the alcohol by the table of Ackermann and Stein- 
mann below. 



ACKERMANN AND STEINMANN'S TABLE FOR OBTAINING THE PER- 
CENTAGE OF ALCOHOL IN THE DISTILLATE OF BEER FROM THE 
IMMERSION REFRACTOMETER READINGS.* 















0) 






a> 






1^ 

0.5 


< 


ill 
< 




•3:10 

r! fl] U 

< 


< 


o.S 
2 " 


< 


■ol" 

III 
< 


0) . 

Pi 


< 


-oi^ 

8>eu 
< 


15-0 


0.00 


0.00 


17.2 


1.38 


1.74 


19.4 


2.74 


3-46 


21.6 


4.02 


5.06 


15-I 


0.06 


0.08 


17-3 


1.44 


1.82 


19-5 


2 


80 


3 


53 


21.7 


4.07 


5-13 


15.2 


0.13 


0.16 


17.4 


1-51 


1.90 


19.6 


2 


86 


3 


61 


21.8 


4-13 


5.20 


15-3 


0.19 


0.24 


17-5 


1-57 


1.98 


19.7 


2 


91 


3 


68 


21 .9 


4.18 


5.26 


15-4 


0.25 


0.32 


17.^ 


1.63 


2.05 


19.8 


2 


97 


3 


75 


22.0 


4.22 


5.32 


15-5 


0.32 


0.40 


17.7 


1.68 


2.12 


19.9 


3 


04 


3 


83 


22.1 


4.28 


5-39 


15-6 


0.38 


0.48 


17.8 


1-74 


2.20 


20.0 


3 


10 


3 


90 


22.2 


4-33 


5-46 


15-7 


0.44 


0.56 


17.9 


1. 81 


2.28 


20.1 


3 


15 


3 


97 


22.3 


4-39 


5-53 


15-8 


0.50 


0.64 


18.0 


1.87 


2.36 


20.2 


3 


20 


4 


04 


22.4 


4-44 


5-59 


15-9 


0-57 


0.72 


18. 1 


1-93 


2.44 


20.3 


3 


26 


4 


II 


22.5 


4-49 


5-65 


16.0 


0.64 


0.80 


18.2 


2.00 


2.52 


20.4 


3 


Z3 


4 


19 


22.6 


4-54 


S-72 


16. 1 


0.70 


0.88 


18.3 


2.06 


2.60 


20.5 


3 


38 


4 


26 


22.7 


4-59 


5-78 


;6.2 


0-77 


0.96 


18.4 


2-13 


2.68 


20.6 


3 


43 


4 


Zi 


22.8 


4.64 


5-85 


16.3 


0.83 


1.04 


18.5 


2. 19 


2.76 


20.7 


3 


50 


4 


41 


22.9 


4.70 


5-92 


16.4 


0.88 


1. 12 


18.6 


2.25 


2.84 


20.8 


3 


56 


4 


48 


23.0 


4.76 


6.00 


16.5 


0-95 


1. 19 


18.7 


2.31 


2.92 


20.9 


3 


61 


4 


55 


23.1 


4.81 


6.07 


16.6 


1. 01 


1.27 


18.8 


2-37 


2-99 


21.0 


3 


67 


4 


63 


23.2 


4.86 


6.13 


16.7 


1-05 


^■33, 


18.9 


2-43 


3-07 


21. 1 


3 


73 


4 


71 


23-3 


4-92 


6.20 


16.8 


1-13 


1-43 


19.0 


2.49 


3-14 


21.2 


3 


78 


4 


77 


23-4 


4-97 


6.27 


16.9 


1. 19 


1-51 


19. 1 


2-55 


3-22 


21-3 


3- 


84 


4 


84 


23-5 


5.02 


6-33 


17.0 


1-25 


1.58 


19.2 


2.61 


3-29 


21.4 


3 


90 


4 


92 








17.1 


1.32 


1.66 


19-3 


2.68 


3-37 


21 -5 


3 


96 


4 


99 









* Zeits. gesamte Brauwesen, 28, 1905, p. 259. 

Determination of Extract. — In cases where extreme accuracy is 
desired, the result obtained by evaporating at ioo° a weighed amount 
of the beer cannot be accepted, on account of the dehydration of the 
maltose at a temperature exceeding 75° C. Unless the evaporation is 
conducted at that temperature (a difficult operation), a closer approxi- 



7i6 



FOOD INSPECTION AND ANALYSIS. 



EXTRACT IN BEER WORT * 
[According to Schultz and Ostermann.] 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


















Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 

per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C 


Cent 

by 
Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 
Weight 


I .0000 


0.00 


0.00 


I .0065 


1 . 69 


1.70 


I. 0130 


3-35 


3-39 


I. 0195 


5.06 


5. 16 


I .0001 


0.03 


0.03 


I .0066 


1.72 


1-73 


1.0131 


3.38 


3-42 


I .0196 


5.09 


5.19 


I .0002 


0.05 


0. 05 


I .0067 


1.74 


1-75 


1.0132 


3-41 


3.46 


1.0x97 


5.12 


5-22 


I .0003 


0.08 


0.08 


I .0068 


1-77 


1.78 


I.OI33 


3-43 


3.48 


I .0198 


5. IS 


5.2s 


I .0004 


0. 10 


0. 10 


I .0069 


1.79 


1.80 


I.OI34 


3.46 


3-Si 


I .0199 


5-17 


5.27 


I .0005 


0.13 


0.13 


I . 0070 


1.82 


1.83 


1.013s 


3.48 


3.53 


I .0200 


S.20 


S.30 


1 .0006 


0.16 


0. 16 


I .0071 


1.84 


1.85 


I. 0136 


3-Si 


3-56 


I .0201 


S.23 


5-34 


I .0007 


0.18 


0.18 


I .0072 


1.87 


1.88 


1 .0137 


3-54 


3-59 


I .0202 


S.25 


5.36 


I .0008 


0.21 


0.21 


1:0073 


1 .90 


I. 91 


I .0138 


3-S6 


3.61 


I .0203 


5.28 


5-39 


1 .0609 


0. 24 


0. 24 


I .0074 


1.92 


1-93 


I. 0139 


3-59 


3-64 


I .0204 


5 -30 


5-41 


1 .0010 


0. 26 


0. 26 


1.0075 


1-95 


I .96 . 


I .0140 


3.61 


3.66 


I .0205 


5-33 


5. 44 


1 .001 1 


0. 29 


0. 29 


I .0076 


1.97 


1.98 


I .0141 


3-64 


3.69 


I .0206 


5.35 


5.46 


I .0012 


0.31 


0.31 


1.0077 


2 .00 


2.02 


I .0142 


3.66 


3.71 


1 .0207 


S.38 


S.49 


1 .001.3 


0.34 


0.34 


I .0078 


2 .02 


2.04 


I. 01 43 


3.69 


3.74 


I .0208 


S-40 


5.51 


1 .0014 


0.37 


0.37 


I .0079 


2.0s 


2.07 


I. 01 44 


3-72 


3.77' 


I .0209 


5-43 


5.54- 


I .0015 


0.39 


0.39 


I .0080 


2, 07 


2.09 


I. 0145 


3-74 


3.79 


1 .0210 


5-45 


5.S6 


I .0016 


0.42 


0.42 


I .0081 


2 . 10 


2.12 


I .0146 


3.77 


3.83 


1 .021 1 


5.48 


5.60 


I .0017 


0.45 


0.4S 


1 .0082 


2.12 


2.14 


I. 0147 


3-79 


3.8s 


I .0212 


5. 50 


5.62 


I .0018 


0.47 


0.47 


I .0083 


2-15 


2.17 


I .0148 


3.82 


3.88 


I .0213 


5,53 


S.6s 


1 .0019 


0. 50 


0.50 


I .0084 


2.17 


2.19 


1 .0149 


3.85 


391 


I .0214 


S-S5 


5.67 


I .0020 


0.52 


0.52 


I .0085 


2. 20 


2 . 22 


I .0150 


3.87 


3-93 


1.0215 


5-57 


5.69 


1 .0021 


0.55 


0.55 


I .0086 


2.23 


2.25 


1.0151 


3.90 


3.96 


1 .0216 


S .60 


5.72 


I .0022 


0.58 


o.s8 


I .0087 


2.25 


2.27 


1.0152 


3-92 


3-98 


I .0217 


5. 62 


5-74 


1.0033 


0. 60 


0.60 


1.0088 


2.28 


2.30 


I-OI53 


3-95 


4 . 01 


I .0218 


5.65 


S.77 


1 .0024 


0.63 


0.63 


I .0089 


2.30 


2.32 


I. 0154 


3-97 


4.03 


I .0219 


5.67 


5.79 


1 .0025 


0.66 


0.66 


I .0090 


2.33 


2.35 


i.oiSS 


4.00 


4.06 


I .0220 


5 -70 


5.83 


1 .0026 


0.68 


0.68 


I .0091 


2.3s 


2.37 


1.0156 


403 


4.09 


I .0221 


5.72 


S.85 


1 .0027 


0.71 


0.71 


1 .0092 


2.38 


2.40 


I. 0157 


4.05 


4. II 


I .0222 


5-75 


5.88 


1 .0028 


0-73 


0.73 


1.0093 


2.41 


2.43 


I. 0158 


4.08 


4.14 


1.0223 


5-77 


5 90 


I .0029 


0. 76 


0.76 


I .0094 


2.43 


2-45 


1.0I59 


4. 10 


4.17 


I .0224 


5 -So 


5.93 


1 .0030 


0.79 


0.79 


1 .0095 


2.46 


2.48 


I .0160 


4.13 


4. 20 


1.0225 


5.82 


5-95 


I .0031 


0.81 


0.81 


I .0096 


2.48 


2.50 


I .0161 


4.16 


4.23 


1 .0226 


5-84 


5. 97 


1.0032 


0.84 


0.84 


I .0097 


2.51 


2.53 


1.0162 


4.18 


4.25 


1 .0227 


5. 87 


6.00 


1.0033 


0.87 


0.87 


I .0098 


2.53 


2.5s 


I .0163 


^;. 21 


4.28 


I .0228 


5-89 


6.02 


1 .0034 


0.89 


0.89 


1 .0099 


2.56 


2.59 


I . 0164 


4-23 


4-30 


1.0229 


592 


6.06 


1.0035 


0.92 


0.92 


I .0100 


2.58 


2.6l 


1.0165 


4. 26 


4.33 


1 .0230 


5-94 


6.08 


1 .0036 


0.94 


0.94 


I . OIOI 


2.61 


2.64 


I .0166 


4.28 


4.3s 


I. 0231 


S-97 


6.11 


1.0037 


0.97 


0.97 


I .0102 


2.64 


2 . 67 


I .0167 


4-31 


4.38 


1 .0232 


5-99 


6.13 


1.0038 


1 .00 


1 .00 


I .0103 


2.66 


2. 69 


I. 0168 


4-34 


4.41 


1.0233 


6. 02 


6.16 


1.0039 


1 .02 


1 .02 


I .0104 


2.69 


2.72 


1 .0169 


4-36 


4-43 


1.0234 


6.04 


6.18 


1 .0040 


I -OS 


i.os 


I. 0105 


2.71 


2.74 


I .0170 


4-39 


4.46 


1.0235 


6.07 


6.21 


1 .0041 


1.08 


1.08 


1 .0106 


2.74 


2.77 


I .0171 


4.42 


4.50 


1.0236 


6.09 


6.23 


1 .0042 


1 . 10 


1 . 10 


I .0107 


2.76 


2.79 


I .0172 


4-44 


4-52 


1.0237 


6. II 


6.25 


I .0043 


1. 13 


1. 13 


1 .0108 


2.79 


2.82 


I. 0173 


4-47 


4-55 


1.0238 


6. r4 


6. 29 


1 .0044 


I. IS 


1. 16 


I . 0109 


2.82 


2.85 


I.OI74 


4-SO 


4.58 


1.0239 


6.16 


6.31 


1 .0045 


1. 18 


1. 19 


I .0110 


2.84 


2.87 


I. 0175 


4-53 


4.61 


I . 0240 


6. 19 


6.34 


1 .0046 


I . 21 


1 . 22 


I .om 


2.87 


2.90 


1.0176 


4.5s 


4.63 


I .0241 


6. 21 


6.31S 


I .0047 


1.23 


1.24 


1 .01 1 2 


2.89 


2 92 


I. 0177 


4.58 


4.66 


I .0242 


6. 24 


6.39 


I .0048 


1.26 


1.27 


1.0113 


2 . 92 


2.95 


I .0178 


4.61 


4 69 


1.0243 


6.26 


6.41 


I .0049 


I . 29 


1.30 


I .01 14 


2.94 


2.97 


1. 0179 


4.63 


4-71 


I . 0244 


6. 29 


6.44 


I .0030 


I. 31 


1-32 


i.oiis 


2.97 


3- 00 


I .0180 


4.66 


4-74 


1.0245 


0.31 


6.46 


1 .0051 


1.34 


I.3S 


1 .0116 


2.99 


3-02 


I .0181 


4.69 


4-77 


I .024(^ 


6.34 


6. so 


1.0052 


1.36 


1-37 


1.0117 


3.02 


3.06 


I .0182 


4-71 


4.80 


1.0247 


6.36 


6.52 


I.OOS3 


1.39 


1 .40 


1 .0118 


3.05 


3.09 


I .0183 


4-74 


4-83 


I .0248 


6.39 


6.SS 


1 .0054 


I. 41 


1.42 


I .0119 


3-07 


3-11 


I .0184 


4.77 


4.86 


I ,0249 


6.41 


6.57 


1.005s 
1 .0056 


1.44 


1. 45 


I .01 20 


3-IO 


3-14 


I .0185 


4-79 


4.88 


1.0250 


6.44 


6.60 


I .46 


1.47 


I .OI2I 


3-12 


3.16 


I. 0186 


4.82 


4-C- 


I .0251 


6.47 


6.63 


1.0057 
1 .0058 


1.49 


1.50 


I .0122 


3.1s 


3.19 


I .0187 


4-85 


4-94 


1.0252 


6.50 


6.66 


i-Si 


1.S2 


I .0123 


3-17 


3.21 


1.0188 


4.88 


4-97 


I .0253 


6.52 


6.68 


I .0059 


I.S4 


I-5S 


I . 0124 


3.20 


3.24 


I .0189 


4.9U 


4.99 


1.0254 


6.55 


6.72 


1 .0060 

1 .0061 
1.0062 
1.0063 
1.0064 


1.S6 


1.S7 


I .0125 


3.23 


3.27 


I . 0190 


4.93 


5.02 


1.0255 


6.58 


6.75 


1-59 
1.62 
1.64 
1.67 


1.60 


I .0126 


3-25 


3.29 


I .0191 


4.96 


5.05 


1.0256 


6.61 


6.78 


1.63 


1 .0127 


3.28 


3-32 


I .0192 


4.98 


5.08 


1.0257 


6.63 


6.80 


I. 6s 


1 .0128 


3.30 


3-34 


1.0193 


5.0I 


5-11 


1 .0258 


6.66 


6.83 


1.68 


I .0129 


3.33 


3.37 j 


1 .0194 


5.04 


S.14 


1.02S9 


6.69 


6.86 



• Calculated from results obtained by drying below 75° C 



ALCOHOLIC BEI^ERAGES. 
EXTRACT IN BEER WORT— {Continued). 



717 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


















Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 

per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 1 5° C. 


Cent 

by 
Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 1 5° C. 


Cent 

by 

Weight 


I .0260 


6.71 


6.88 


1.0325 


8.27 


8.54 


1.0390 


9.92 


10.31 


I .0435 


II-S3 


12.05 


1 .026^ 


6.74 


6.92 


1.0326 


8.29 


8.56 


I .0391 


9.9s 


10.34 


1.0456 


ii-SS 


12.08 


1 .0262 


6.77 


6.95 


1.0327 


8.32 


8.59 


1.0392 


9-97 


10.36 


I-04S7 


11.57 


12. lO 


1.0263 


6.80 


6.98 


1.0328 


8.34 


8.61 


1.0393 


9.99 


10.38 


1.0458 


1 1 . 60 


12.13 


1 . 0264 


6.82 


7 .00 


1.0329 


8.37 


8.6s 


1.0394 


10.02 


10.41 


1.0459 


II .62 


12.15 


I .0265 


6.85 


7-03 


1.0330 


8.40 


8.68 


1.0395 


10. 04 


10.44 


I . 0460 


11.65 


12.19 


1 .0266 


6.88 


7.06 


I. 0331 


8.43 


8.71 


1.0396 


10.06 


10.46 


I .0461 


11.67 


12.21 


I .0267 


6.91 


7.09 


1.0332 


8.45 


8.73 


1.0397 


10.00 


10.49 


I .0462 


11.70 


12.24 


1.0268 


6.93 


7.12 


1.0333 


8. 48 


8.76 


I .0398 


10 . 1 1 


10. SI 


I .0463 


11.72 


12. 26 


I .0269 


6.96 


7-15 


I -0334 


8.51 


8.79 


1.0399 


10. 13 


10. S3 


I .0464 


II.7S 


12.30 


I .0270 


6.99 


7.18 


1.033s 


8.53 


8.82 


I .0400 


10. 16 


10.57 


1.046s 


11.77 


12.32 


I .0271 


7.01 


7. 20 


1.0336 


8.56 


8.8s 


■ I .0401 


10.18 


10.59 


I .0466 


11.79 


12.34 


I .0272 


7.04 


7.23 


1.0337 


8.59 


8.88 


I .0402 


10. 20 


10. 61 


1 .0467 


11.82 


12.37 


1.0273 


7.07 


7 . 26 


1.0338 


8.61 


8.90 


I .0403 


10. 23 


10. 64 


I .0468 


11.84 


12.39 


1.0274 


7.10 


7.29 


1.0339 


8.64 


8.93 


I .0404 


10.2s 


10.66 


I .0469 


11.87 


12.43 


1.0275 


7.12 


7.32 


1.0340 


8.67 


8.96 


1.040s 


10. 27 


10. 69 


I .0470 


11.89 


I2.4S 


1 .0276 


7. IS 


7.3s 


1.0341 


8.70 


9.00 


1 .0406 


10.30 


10. 72 


1.0471 


11.92 


12.48 


1.0277 


7.18 


7.38 


1.0342 


8.72 


9.02 


I .0407 


10. 32 


.10.74 


1.0472 


11.94 


12.50 


I .0278 


7.21 


7-41 


1.0343 


8. 75 


9.05 


I . 0408 


10.3s 


10.77 


1.0473 


11.97 


12.54 


I .0279 


7.23 


7-43 


1.0344 


8.78 


9.0S 


I .0409 


10.37 


10.79 


1.0474 


11.99 


12. s6 


I .0280 


7.26 


7.46 


1.0345 


8.80 


9.10 


I .0410 


10.40 


10.83 


1-0475 


12.01 


12.58 


1 .0281 


7.28 


7.48 


1.0346 


8.83 


9.14 


1 .041 1 


10.42 


10.85 


I .0476 


I 2 .04 


12. 6i 


I .0282 


7.30 


7. SI 


I .0347 


8.86 


9.17 


I .041 2 


10.45 


I0.88 


1.0477 


12.06 


12 . 64 


I .0283 


7.33 


7.54 


1.0348 


8.88 


9.19 


I. 0413 


10.47 


10 . 90 


I .0478 


12 .09 


12.67 


I .0284 


7.3s 


7.56 


1.0349 


8.91 


9.22 


I. 0414 


10.50 


10.93 


1.0479 


I 2 . 1 1 


12.69 


I .0285 


7-37 


7.S8 


1.0350 


8.94 


9.25 


I. 0415 


10. 52 


10. 96 


I . 0480 


12.14 


12.72 


I .0286 


7-39 


7.60 


1.0351 


8.97 


9.28 


I .0416 


10. 55 


10.99 


1 .0481 


12.16 


12.74 


1 .0287 


7.42 


7.63 


1.0352 


8.99 


9.31 


1.0417 


10. S7 


II .01 


I .0482 


12.19 


12.78 


1.0288 


7-44 


7.6s 


1.0353 


9.02 


9.34 


I .0418 


10. 60 


11 .04 


1 .0483 


12.21 


12.80 


1 .0289 


7.46 


7.68 


I. 0354 


9.0s 


9-37 


I .0419 


10.62 


II .06 


1 . 0484 


12.23 


12.8a 


1 .0290 


7.48 


7.70 


I.03S5 


9.07 


9.39 


I .0420 


10.6s 


11 . 10 


1.048s 


12.26 


12.8s 


I .0291 


7. SI 


7-73 


1.0356 


9. 10 


9.42 


1 .0421 


10.67 


11.12 


1 .0486 


12.28 


12.88 


I .0292 


7.53 


7.7S 


1.0357 


913 


9.46 


I .0422 


10. 70 


II. 15 


I .0487 


12.31 


12.91 


1.0293 


7.5s 


7.77 


I 0358 


9. IS 


9.48 


1.0423 


10.72 


II. 17 


1.0488 


12.33 


12.93 


I .0294 


7.57 


7.79 


I. 0359 


9.X8 


9.51 


I .0424 


10.75 


11.21 


I . 0489 


12.36 


12.96 


1.0295 


7 .60 


7.82 


1.0360 


9. 21 


9.54 


1.042s 


10.77 


11.23 


I .0490 


12.38 


12.99 


I .0296 


7 .62 


7.85 


I. 0361 


9.24 


9.57 


I . 0426 


10. 80 


11.26 


I .0491 


12.41 


13-02 


1 .0297 


7.64 


7.87 


1.0362 


9. 26 


9.60 


I. 0427 


10.82 


11.28 


1.0492 


12.43 


13-04 


1 .0298 


7.66 


7.89 


I -0363 


9.29 


963 


I .0428 


10.8s 


11.31 


1.0493 


12.45 


13.06 


I .0299 


7.69 


7.92 


1.0364 


9.31 


9.05 


I .0429 


10.88 


11-35 


1.0494 


12.48 


13-10 


1 .0300 


7.71 


7.94 


1.0365 


9.34 


9.68 


1.0430 


10.90 


11.37 


I. 049s 


12.50 


13.1a 


1 .0301 


7.73 


7.96 


1.0366 


9.36 


9.70 


1. 043 1 


10.93 


11 .40 


I .0496 


12-53 


13. IS 


1 .0302 


7-75 


7.98 


1.0367 


9.38 


9.72 


1.0432 


10. 95 


11.42 


1.0497 


12.55 


13.17 


1.0303 


7-77 


8.01 


1.0368 


9.41 


9.76 


1.0433 


10.98 


II .46 


I .0498 


12.58 


13-21 


1.0304 


7.80 


8.04 


1.0369 


9.43 


9-78 


1.0434 


1 1 .00 


11.48 


1.0499 


12.60 


13.23 


1.0305 


7.82 


8.06 


1.0370 


9.4s 


9.80 


1.043s 


II .03 


II. SI 


I .0500 


12.63 


13.26 


1.0306 


7.84 


8.06 


1.0371 


9.48 


9.83 


I .0436 


II .05 


11.53 


r .0501 


I 2 . 6.5 


13.28 


1.0307 


7.86 


8.10 


1.0372 


9.50 


9.85 


1.0437 


11.08 


11.56 


I .0502 


I 2. 67 


13.31 


I .0308 


7.89 


8.13 


1.0373 


9.52 


9.88 


1.0438 


n . 10 


11.59 


1.0503 


12.70 


13.34 


1.0309 


7.91 


8. IS 


1.0374 


9.55 


9.91 


I .0439 


II. 13 


11.62 


I .0504 


12.72 


13.36 


I .0310 


7.93 


8.18 


I. 037s 


9.57 


9-93 


I .0440 


11.15 


1 1 . 64 


1.0505 


12.75 


13.39 


1.0311 


7.95 


8.20 


1.0376 


9. 59 


9.9s 


1 .0441 


11.18 


11.67 


I .0506 


12.77 


13.42 


I .0312 


7.98 


8.23 


1.0377 


9.62 


9.98 


1.0444 


1 1 . 20 


11.70 


I .0507 


12.80 


13.4s 


I. 0313 


8.00 


8.25 


1.0378 


9.64 


10.00 


1.0443 


11.23 


11.73 


I .0508 


12.82 


13.47 


1.0314 


8.02 


8.27 


1.0379 


9.66 


10.03 


1.0444 


11. 25 


11.75 


1.0509 


12.8s 


13-SO 


1-0315 


8.04 


8.29 


1 .0380 


9.69 


10.06 


1.0445 


11.28 


11.78 


I .0510 


12.87 


13. S3 


I. 0316 


8.07 


8.33 


X.0381 


9.71 


10.08 


I .0446 


II .30 


11.80 


1 .0511 


I 2 . 90 


13.56 


1.0317 


8.09 


8.35 


1.0382 


9.73 


10. 10 


1.0447 


11.33 


11.84 


1.0512 


12.92 


13. S8 


1. 0318 


8. II 


8.37 


1.0383 


9.76 


10. 13 


I .0448 


II .35 


11.86 


1.0513 


12.94 


13.60 


1.0319 


8.13 


8.39 


1.0384 


9.78 


10.16 


I .0449 


11.38 


11.89 


1.0514 


12.97 


13.64 


1.0320 


8.i6 


8.42 


1.0385 


9.81 


10.19 


1.0450 


II .40 


11.91 


1.0S15 


12.99 


13.66 


1.0321 


8.18 


8.44 


1.0386 


9-83 


10. 21 


1.0451 


II .43 


11.9s 


1.0516 


13.02 


13- 69 


I .0322 


8.20 


8.46 


1.0387 


9.85 


10.23 


1.0452 


11.4s 


11-97 


1. 0517 


13.04 


13.71 


1.0323 


8.22 


8.49 


1.0388 


9.88 


10. 26 


1.0453 


11.48 


I 2.00 


1.0518 


13.07 


13.7s 


1.0324 


8.2s 


8.52 


1.0389 


9.90 


10. 29 


1.0454 


II .50 


12.02 


1-0519 


13.09 


13.77 



7i8 



FOOD INSPECTION AND ANALYSIS. 
EXTRACT IN BEER WOWT— {Continued). 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 
Gravity 
at is" C. 


















Per 

Cent 

by 

Weight 


Grams 

per 
100 cc. 


Gravity 
at 15° C. 


Per 
Cent 

by 
Weight 


Grams 

per 
100 cc. 


Gravity 
at is" C. 


Per 

Cent 

bv 

Weight 


Grams 

per 
100 cc. 


Gravity 
at 15° C. 


Per 

Cent 

by 

Weight 


Grams 

per 
100 cc. 


I .0520 


13.12 


13 80 


1.0585 


14-75 


15.61 


1 .0650 


x6.2S 


17-31 


1.0715 


17.81 


X9.08 


I .0521 


13.14 


13.82 


1.0586 


i-i.78 


xs-65 


I. 0651 


x6. 27 


X7-33 


1 .0716 


17.84 


X9. 12 


1.0522 


13.16 


13.85 


1.0587 


14-8X 


X5-68 


I .0652 


X6.30 


17.36 


1.07x7 


17.86 


19-X4 


1 .0523 


13.19 


13-88 


1 .0588 


X4-83 


15-70 


I .0653 


16.32 


17-39 


1.0718 


17.88 


19.16 


1.0524 


13-21 


13-90 


1.0589 


14.86 


15-74 


X .0654 


16.35 


17.42 


1.0719 


17.90 


19-19 


X .0525 


13.24 


13-04 


1 .0590 


14.89 


15-77 


1.0655 


16.37 


17-44 


1 . 0720 


17-03 


19.22 


I .0526 


13. 26 


13.96 


I. 0591 


14.91 


1579 


X .0656 


I 6 . 40 


17-48 


I .0721 


17.95 


19.24 


I 0527 


13 29 


13-99 


1.0592 


14-94 


15.82 


I .0657 


X6.42 


17.50 


1.0722 


17.97 


19-27 


I .0528 


13.31 


14.01 


1.0593 


14.96 


15-85 


1.0658 


16.45 


17.53 


1-0723 


17.99 


19.29 


1.0529 


13-34 


14-05 


I. 0594 


14.99 


15-88 


1 .0659 


16.47 


17.56 


1.0724 


18.02 


19.32 


I .0530 


13.36 


14.07 


I. 0595 


13.02 


15-9X 


I .0660 


16.50 


17.59 


X.0725 


18.04 


X9-3S 


I -0531 


13.38 


14.09 


I .0596 


15.04 


15-94 


I .0661 


16.52 


17.61 


X .0726 


18.06 


X9.37 


I .0532 


13.41 


14. 1 2 


1.0597 


15.07 


15-97 


I .0662 


16.54 


17.63 


1.0727 


18.08 


19-39 


1 .0533 


13-43 


14-15 


I .0598 


X5-09 


15-99 


1 .0663 


16.57 


17.67 


1.072S 


18.11 


19-43 


I.OS34 


13.46 


14.18 


1.0599 


15-11 


16.02 


I .0664 


x6.S9 


17.69 


I .0729 


18.13 


19-45 


1.0S3S 


13-48 


14. 20 


I .0600 


15-14 


16.05 


I .0665 


16.62 


17-73 


X .0730 


xS.is 


19.47 


1 .0536 


13-51 


14-23 


I .0601 


15 . 16 


16.07 


I .0666 


x6. 64 


17-75 


I-073I 


18.17 


X9-50 


I .0537 


13-53 


14. 26 


I .0602 


15-X8 


16.09 


I .0667 


16.67 


17-78 


1.0732 


18.20 


19-53 


1.0538 


13.56 


14.29 


I .0603 


15. 20 


16 . X 2 


1.0668 


16. 69 


17-80 


X.0733 


18.22 


19-55 


I-OS39 


13.58 


1431 


I . 0604 


15 23 


16 15 


I 0669 


16.72 


17-84 


X.0734 


18.24 


19-58 


1.0540 


13.61 


14-34 


1 .0605 


15-25 


16.17 


I .0670 


16.74 


17.86 


1.0735 


18.26 


19 . 60 


1 .0541 


13.63 


14-37 


I .0606 


15-27 


16. 20 


X .0671 


16.76 


17.88 


X.0736 


18.29 


19.64 


I .0542 


13.66 


14.40 


I .0607 


15-29 


16. 22 


X .0672 


16.79 


17-92 


x-0737 


18. 31 


19 . 66 


I .0543 


13-68 


14.42 


I .0608 


15-31 


x6. 24 


1.0673 


16.81 


X7-94 


x-0738 


X8.33 


19.68 


1.0S44 


13-71 


14.46 


I .0609 


X5-34 


16. 27 


X .0674 


16.84 


X7-98 


X.0739 


X8.35 


19.71 


1.0545 


13-73 


14.48 


I . 0610 


15-36 


16.30 


1.067s 


16.86 


x8.oo 


1.0740 


18.38 


19.74 


I .0546 


13-76 


14-51 


1 .061 1 


15-38 


16.32 


I .0676 


16.89 


X8.03 


I .0741 


18.40 


19.76 


I -0547 


13.78 


14-53 


I .061 2 


15-40 


16.34 


1 .0677 


16.91 


18.05 


1 .0742 


18.42 


19-79 


1.0548 


13-81 


14-57 


I .9613 


X5-43 


16.38 


1.0678 


16.94 


18.09 


X .0743 


18.44 


19.81 


1.0549 


13-83 


14-59 


I .0614 


X5-4S 


16 .40 


1 .0679 


16 . 96 


x8.ii 


1.0744 


X8.47 


19.84 


I .0550 


13-86 


14.62 


I .06x5 


15-47 


16.42 


I .0680 


16.99 


18.15 


1.074s 


18.49 


19.87 


1.0551 


13-88 


14.64 


1 .0616 


15-49 


16.44 


I. 0681 


17 .01 


18.17 


I .0746 


18.51 


19.89 


1.0552 


13-91 


14.68 


1.0617 


X5-52 


16.48 


1.0682 


X7-03 


18.19 


1.0747 


18.53 


19.91 


1 .0553 


13-93 


14.70 


1.06x8 


15.54 


16.50 


X.0683 


17 .06 


18.23 


X .0748 


18.55 


19.94 


1.05S4 


13.96 


14-73 


I .0619 


15-56 


16.52 


X .0684 


17-08 


18.25 


1.0749 


18.57 


19.96 


1.0555 


13.98 


14.76 


I .0620 


X5-58 


16.55 


1.0685 


17. IX 


18.28 


X.0750 


18.59 


19-98 


1.0556 


14.01 


14.79 


I .0621 


x5-6o 


16.57 


I.06S6 


17-13 


1H.31 


I .075X 


18.62 


20 .02 


1.0557 


14-03 


14.81 


I .0622 


15-63 


16.60 


1.0687 


17.16 


18.34 


X.07S2 


18.64 


20.04 


1.0558 


14.06 


14.84 


I .0623 


15-65 


16.62 


1.0688 


17.18 


18.36 


X.07S3 


18.66 


20.07 


1.0559 


14.08 


14-87 


1 .0624 


15-67 


16. 64 


X .0689 


17.21 


18.40 


X.0754 


18.68 


20.09 


1 .0560 


14.11 


14.90 


1.0625 


15.69 


16.66 


1 .0690 


17-23 


18.42 


1.0755 


1S.70 


20. II 


1.0561 


14-13 


14.92 


I .0626 


15.72 


16.70 


I .0691 


17-25 


18.44 


1-0756 


18.72 


20. 14 


1 .0562 


14. t6 


14.96 


I .0627 


15.74 


16.73 


I .0692 


17.28 


18.48 


1.0757 


18.74 


20. 16 


1.0563 


14.18 


14.98 


1.0628 


15.76 


16.75 


1.0693 


17-30 


18.50 


X.0758 


18.76 


20.18 


1.0564 


14. 21 


15.01 


I .0629 


15.78 


16.77 


I .0694 


X7-33 


X8.53 


I.0759 


18.78 


20. 21 


i'056s 


14-23 


15.03 


1.0630 


X5.80 


16.80 


I .069s 


17-35 


18.56 


1 .0760 


18.81 


20. 24 


X.0566 


14. 26 


15.07 


1.0631 


15.83 


16.83 


1 .0696 


17-38 


18.59 


X .0761 


18.83 


20. 26 


1.0567 


14.28 


15.09 


1.0632 


X5-85 


X6.85 


I .o6q7 


17.40 


18.61 


I .0762 


18.85 


20. 29 


1.0568 


14-31 


15.12 


1.0633 


15-87 


16.87 


I .0698 


17-43 


18.65 


X.0763 


18.87 


20.31 


1 .0569 


14-33 


15.15 


1.0634 


15.89 


16.90 


I .0699 


17.45 


18.67 


I .0764 


18.89 


20.33 


1.0570 


14.36 


15.18 


1.063s 


15.92 


16.93 


I .0700 


17-48 


18.70 


1.076s 


18.91 


20.36 


1.0571 


14.38 


15.20 


1 .0636 


15.94 


16.95 


I .0701 


17-50 


18.73 


1 .0766 


18.93 


20.38 


1.0572 


14.41 


15.23 


1.0637 


15-96 


16.98 


1 .0702 


17-52 


18. 75 


1.0767 


18.95 


20.40 


1.0573 


14.44 


15.27 


1.0638 


15-98 


17 .00 


1.0703 


17-54 


18.77 


1.0768 


18.97 


20.43 


I.OS74 


14.46 


15.29 


1.0639 


16.01 


17.03 


1 .0704 


17-57 


18.81 


1.0769 


19.00 


20.46 


1.057s 


14.49 


15.32 


I .0640 


16.03 


17 .06 


1.070s 


17.59 


18.83 


1 .0770 


19.02 


20.48 


1.0576 


14.52 


15.36 


I .0641 


16.05 


17.08 


1 .0706 


17. 6x 


18.85 


1 .0771 


19.04 


20.51 


I.OS77 


14.54 


IS -38 


I .0642 


16.07 


17.10 


X.0707 


17.63 


18.88 


1 .0772 


19. 06 


20.53 


1.0578 


14.57 


15-41 


1 .0643 


16.09 


17.12 


1 .0708 


17.66 


18.91 


1.0773 


19.08 


20.55 


I.OS79 


14.59 


15-43 


1 .0644 


16. 12 


17.16 


1 .0709 


17.68 


18.93 


1.0774 


19. 10 


20.58 


1 .0580 


14.62 


15.47 


1.064s 


16. 14 


17.18 


X . 0710 


17.70 


18.96 


1.0775 


19.12 


20. 60 


1.0581 


14.6s 


15.50 


I .0646 


16.16 


17 . 20 


1 .071 1 


17.72 


18.98 


1.0776 


19-14 


20.63 


1.0584 


14.67 


15.52 


1.0647 


16.18 


17.23 


1 .0712 


17.75 


19.01 


X.0777 


19.17 


20.66 


1.CS&3 


14..70 


IS-S6 


I .0648 


16. 21 


17.26 


1.0713 


17-77 


19.04 


1.0778 


19.19 


20.68 


1 .0584 


14.73 


15-59 


5 0649 


X6.2^ 


1.7.28 


X -0714 


17-79 


19.06 


1.0779 


19. 21 


20.71 



ALCOHOLIC BEyERAGES. 



719 



EXTRACT IN BEER ^NOV^T— {Continued). 





Extract. 


1 
Specific 


E.xtract. 


Specific 


Extract. 


1 
Specific 


Extract. 


Specific 


















Gravity 
at 15° C. 


Per 

Cent 

by 

Weight 


Grams 

l)er 
100 cc. 


Gravity 
at 15° C. 


Per 

Cent 

by 

Weight 


Grams 

per 
100 cc. 


Gravity 
at 15° C. 


Per 

Cent 

by 

Weight 


Grams 

per 
loo cc. 


Gravity 
at 15° C. 


Per 

Cent 

by 

Weight 


Grams 

per 
loo cc. 


1 .0780 


19.23 


20.73 


1.0845 


20 . 70 


22 . 4^ 


I .0910 


22. 19 


24. 2t 


1 .0975 


23-59 


25.89 


1 .0781 


19.2s 


20. 7 5 


1.0846 


20.73 


22.48 


1 .091 1 


22.21 


24-24 


1 .0976 


23-61 


25.92 


I .0782 


19.27 


20.78 


1.0847 


20.75 


22.50 


I . 091 2 


22.23 


24. 26 


1.0977 


23-63 


25-94 


1.0783 


19.29 


20.80 


1.0848 


20 . 77 


22.53 


1.0913 


22 . 26 


24-29 


1 .0978 


23.65 


25-97 


1 .0784 


19-31 


20.82 


I .0849 


20.79 


22.55 


1.0914 


22.28 


24-31 


1.0979 


23-67 


25-99 


t .0785 


19-3.1 


20.85 


I .0850 


20.81 


22.58 


1 .0915 


22 . 30 


24.34 


I .0980 


23.69 


26.01 


1 .07S6 


10.3'' 


20.88 


I .o8si 


20.83 


22.61 


I .091 6 


22.32 


24.37 


1 .0981 


23.71 


26.04 


1.0787 


19.38 


20.90 


1.0852 


20.86 


22 . 64 


1.0917 


22.34 


24.39 


1 .0982 


23-73 


26.06 


t.0788 


19.40 


20.93 


1.0853 


20.88 


22.66 


I .0918 


22.37 


24.42 


I .0983 


23-76 


26 .09 


t .0789 


19.42 


20.95 


I .0854 


20 .90 


22.68 


1 .0919 


22.39 


24.44 


I .0984 


23-78 


26. 11 


T .0700 


19-44 


20.98 


1.0855 


20.93 


22.72 


1 .0920 


22.41 


24.47 


1.0985 


23.80 


26. 14 


I .0701 


19.46 


21 .00 


1.0856 


20.9s 


22.75 


I .0921 


22.43 


24.49 


1 .0986 


23.82 


26. 17 


I .0702 


19.49 


21 .03 


1.0857 


20.98 


22.78 


I .0922 


22.45 


24-51 


1 .0987 


23-84 


26. 19 


I.O703 


19-51 


21 .06 


1.0858 


21.01 


22 . Si 


1.0923 


22 48 


24-54 


1.0988 


23 -86 


26. 22 


1.0794 


t9-S3 


21 .08 


I .0859 


21 .04 


22.84 


1.0924 


22.50 


24.56 


I .0989 


23-88 


26. 24 


I-079S 


19-56 


21 . II 


1.0860 


21 .06 


22.87 


1.092s 


22.52 


24.60 


I .0990 


23.90 


26. 27 


1 .0796 


19-5S 


21.14 


I. 0861 


21 .09 


22.90 


I .0926 


22.54 


24.62 


I .0991 


23-92 


26.30 


1.0797 


19. 60 


21.16 


I .0862 


21 . 1 1 


22.93 


1.0927 


22.56 


24.64 


I .0992 


23.94 


26.32 


1 .0798 


19.63 


21 . 20 


1.0863 


21.13 


22.96 


1.0928 


22.59 


24.67 


1-0993 


23.97 


26.3s 


1.0799 


19.65 


21 . 22 


I . 0864 


21.16 


22.99 


1 .0929 


22.61 


24.70 


1.0994 


23.99 


26.37 


I .0800 


19-67 


21 . 24 


1.0865 


21 . 19 


23.02 


1.0930 


22.63 


24.73 


1-0995 


24.01 


26.40 


I .0801 


19.70 


21.28 


1.0866 


21.22 


23.06 


1.0931 


22 .65 


24.76 


I .0996 


24.03 


26.42 


I .0S02 


19.72 


21.30 


1.0867 


21.25 


23.09 


1.0932 


22.67 


24.78 


1.0997 


24.05 


26.44 


I .0803 


19-74 


21.33 


1.0868 


21.28 


23.12 


1.0933 


22 .69 


24.81 


1 .0998 


24.07 


26.47 


I .0804 


19-77 


21.36 


1 .0869 


21 .30 


23-iS 


1.0934 


22.71 


24.83 


1.0999 


24.09 


26.49 


I .0805 


19-79 


2.1 . 38 


I .0870 


21.33 


23-18 


I. 0935 


22.73 


24.86 


I . 1000 


24. 1 1 


26.52 


I .0806 


19.81 


21 .41 


I. 0871 


21.35 


23. 21 


1.0936 


22.75 


24-89 


I . 1001 


24-13 


26.5s 


1 .0807 


19.84 


21 .43 


1.0872 


21.37 


^3.23 


1-0937 


22.77 


24.91 


1 . 1002 


24-15 


26.57 


I .0808 


19.86 


21 .46 


1.0873 


21 .39 


23.20 


1-0938 


22.80 


24-93 


1 - 1003 


24.17 


26 . 60 


1 .0809 


19.88 


21.49 


1.0874 


21.41 


23.28 


1.0939 


22.82 


24.96 


1 . 1004 


24.19 


26. 62 


1 .0810 


19.91 


21.52 


1.0875 


21.43 


23-31 


1 .0940 


22.84 


24-99 


1 . 1005 


24. 21 


26.65 


i.o8ii 


19-93 


21 .55 


1.0876 


21 .45 


23-33 


1 .0941 


22.86 


25-01 


1 . 1006 


24-23 


26.68 


1. 081 2 


19.96 


21.58 


1.0877 


21.47 


23-36 


1.0942 


22.88 


25-03 


1 . 1007 


24- 25 


26. 70 


I .0813 


19.98 


21 .60 


1.0878 


21.49 


23-38 


1-0943 


22 . 90 


25.06 


1 . 1008 


24.28 


26.73 


1 .0814 


20.00 


21 .63 


1.0879 


21.51 


23-40 


1.0944 


22.92 


25.08 


1 . 1009 


24.30 


26.7s 


1. 0815 


20.03 


21 .66 


1.0880 


21.54 


23-43 


1.0945 


22.94 


25.11 


1 . 1010 


24-32 


26.78 


i.o8i6 


20 .05 


21 . 69 


I. 088 I 


21.56 


23-45 


1 . 0946 


22.96 


25.14 


1 . 101 1 


24-34 


26. 8r 


1 .0817 


20.07 


21 . 71 


1.0882 


21.58 


23.48 


1.0947 


22.98 


25.16 


I . 1012 


24-36 


26.83 


T.c8r8 


20. 10 


21.74 


1.0S83 


2 1 . ()0 


23.50 


1.0948 


23.00 


25.18 


1.1013 


24-30 


26.86 


1 .0819 


20. I 2 


21.77 


1.08S4 


21.62 


23-52 


1.0949 


23.03 


25.21 


1 . 1014 


24.41 


26.88 


I . 0820 


20 . 14 


21.79 


1.0885 


21 .64 


23.55 


1.0950 


23.05 


25.24 


1 . 1015 


24-43 


26.91 


I .0821 


20. 17 


21.83 


1.0886 


21 .66 


23-58 


1.0951 


23-07 


25.26 


I . ioi6 


24-45 


26.93 


I .0822 


20. 19 


21.85 


1.0887 


21.68 


23-60 


1.0952 


23. 10 


25.29 


1 . 1017 


24.47 


26.9s 


1.0823 


20. 21 


21.87 


1.08S8 


21.71 


23-63 


1.0953 


23.12 


25.31 


I . ioi8 


24.49 


26.98 


I .0824 


20. 24 


.? 1 . 9 1 


1.0889 


21.73 


23.66 


I. 0954 


23.14 


25.34 


I . 1019 


24.51 


27 .00 


1 .082s 


20. 26 


21 93 


I . 0890 


21.75 


23-69 


I. 0955 


23.16 


25.37 


1 . 1020 


24.53 


27-03 


1.0826 


20.28 


21 . 96 


I .0891 


21.77 


23.72 


1.0956 


23.18 


25.39 


1 . 1021 


24.55 


27 .06 


1.0827 


20.31 


21.99 


I .0892 


21.79 


23-74 


1.0957 


23.20 


25.42 


1 . 1022 


24.57 


27.08 


1.0828 


20.33 


22.01 


I .0893 


21.82 


23-77 


1.0958 


23.23 


25-45 


1.1023 


24 . 60 


27.11 


I .0829 


20.35 


22.04 


I .0894 


21.84 


23.79 


1.0959 


23.2s 


25.47 


I . 1024 


24. 62 


27.14 


I .0830 


20-37 


22.06 


1.0895 


21.86 


23.82 


1 . 0960 


23.27 


25.50 


1.1025 


24.64 


27.17 


I .0831 


20.39 


22.08 


1.0896 


21. 8y 


23-S5 


I .0961 


23.29 


25-53 


I . 1026 


24.66 


27- 19 


I .0832 


20. 41 


22.11 


1.08,7 


21 .91 


23-87 


I .0962 


23-31 


25.55 


1 . 1027 


24.68 


27.21 ■ 


1.0833 


20.43 


22.13 


I .0898 


21 .93 


23.90 


I . 0963 


23-33 


25.58 


1 . 1028 


24.70 


27-24 


I .0834 


20.46 


22.16 


I .0899 


21 . 96 


23-93 


I .0964 


23-35 


25.60 


1 . 1029 


24.72 


27. 26 


1.083s 


20.48 


22. 19 


I .0900 


21.98 


23-96 


t.0965 


23-37 


25-63 


I. 1030 


24.74 


27.29 


1.0S36 


20.50 


22.21 


I .0901 


22.00 


23.98 


I .0966 


23-39 


25.66 


1.1031 


24.76 


27.32 


1.0S37 


20.52 


22. 24 


I .0902 


22 . 02 


24.01 


1.0967 


23-41 


25.68 


1.1032 


24.78 


27-34 


1.0S38 


20.54 


22 . 26 


1.0903 


22.04 


24.03 


1.0968 


23.44 


25.71 


I. 1033 


24.81 


27.37 


1.0839 


20.56 


22. 29 


I .0904 


22 .06 


24.05 


1 .0969 


23.46 


25-73 


1. 1034 


24-83 


27-39 


I .0S40 


20.59 


22.32 


I .0905 


22.08 


24.08 


1.0970 


23-48 


25.76 


I-I03S 


24-85 


27.42 


1.0841 


20.62 


22.35 


1 .0906 


22. 10 


24. 1 1 


1.097I 


23-50 


25.79 


1 . 1036 


24.87 


27.4s 


I .0842 


20. 64 


22.38 


1.0907 


22.12 


24. 13 


1 . 0972 


2352 


25.81 


1.1037 


24.89 


27-47 


1.0843 


20 . 66 


22 .40 


I .0908 


22. 15 


24. 16 


I -0973 


23.55 


25.84 


1.1038 


24.92 


27.50 


1.0844 


20.68 


22.42 


I .0909 


22.17 


24.18 


1.0974 


23-57 


25-86 


1 1039 


24.94 


27.53 



720 



FOOD INSPECTION AND ANALYSIS. 
EXTRACT IN BEER WORT— {Concluded). 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


















Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


at is°C. 


Cent 

by 

Weight 


per 
100 CO. 


at 1 5° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


1 . 1040 


24.96 


27.56 


1. 1 095 


26. 16 


29.03 


1.1150 


27.29 


30.43 


1. 1 20s 


28.38 


31.81 


I . 1041 


24.98 


27.58 


1 . 1096 


26.18 


29.06 


1. 1151 


27.31 


30.4s 


I . 1206 


28. 40 


31-83 


I . 1042 


25 .00 


27 . 60 


I. 1097 


26. 20 


29 .08 


1.1152 


27.33 


30.47 


1 . 1 207 


28.42 


31-86 


1.104.? 


25.03 


27.63 


I . 1098 


26.23 


29. 1 1 


1.1153 


27.3s 


30.50 


1. 1 208 


28.44 


31-88 


1. 1044 


25.05 


27.66 


I. 1099 


26.25 


29.13 


I. 1154 


27.37 


30.52 


I . I 209 


28.46 


31-90 


I. I 045 


25.07 


27 .69 


I . IIOO 


26. 27 


29. 16 


1.1155 


27.38 


30.55 


1 . I 2TO 


28 . 48 


31.93 


1 . 1046 


25.09 


27.72 


I . I lOI 


26. 29 


29.19 


1. 1156 


27.40 


30.57 


I . I 21 1 


28.50 


31.95 


I. 1047 


25.11 


27-74 


I . II02 


26.31 


29. 21 


1. 1157 


27.42 


30.59 


1 . 1 21 2 


28.52 


31.98 


1 . 1048 


25.14 


27.77 


I.IIO3 


26.33 


29.24 


1.1158 


27-44 


30.62 


1.1213 


28.54 


32.00 


1 . 1049 


25.16 


27.79 


I . II04 


26.35 


29. 26 


I.II59 


27-46 


30.64 


I . 1214 


28.56 


32.03 


1.1050 


25.18 


27.82 


I.II05 


26.37 


29.29 


I .1160 


27.48 


30.67 


1.121S 


28.58 


32.05 


1.1051 


25. 20 


27-85 


I . II06 


26.39 


29.32 


i.ii6i 


27.50 


30.69 


I . I2l6 


28.60 


32.08 


1 . 1052 


25 . 22 


27.87 


I . IIO7 


26. 41 


29.34 


1.1162 


27.52 


30.72 


I . I2I7 


28.62 


32.11 


I.IOS3 


25.24 


27.90 


I. 1108 


26.44 


29-37 


1.1163 


27.54 


30.75 


I.I2I8 


28.64 


32.13 


1.1054 


25.27 


27.93 


I . II09 


26.46 


29-39 


1 . 1164 


27.56 


30.77 


I . I 219 


28.66 


32.15 


I.IOSS 


25.29 


27.96 


I . IIIO 


26.48 


29-42 


1.1165 


27-58 


30.80 


I . 1220 


28.68 


32.18 


I. 1056 


25-31 


27.98 


1 . 1 1 1 1 


26.50 


29-44 


I. 1166 


27 . 60 


30.82 


I . I 221 


28.70 


32.20 


1.IOS7 


25.3.? 


28.00 


I . III2 


26.52 


29.46 


1.1167 


27.62 


30.8s 


I . 1222 


28.72 


32.23 


1.1058 


25.35 


28.03 


I.III3 


26.54 


29-49 


I. II 68 


27.64 


30.87 


I. 1223 


28.74 


32.2s 


I. 1059 


25.38 


28.06 


I . III4 


26.56 


29.51 


I . 1169 


27.66 


30.89 


I . 1224 


28.76 


32.27 


1 . 1060 


25.40 


28.09 


I.III5 


26.58 


29-54 


1.1170 


27.68 


30.92 


1.I22S 


28.78 


32.30 


I . 1061 


25.42 


28.12 


I . III6 


26.60 


29.57 


1.1171 


27.70 


30.94 


I . 1226 


28.80 


32.32 


1 . 1062 


25.44 


28.14 


I.III7 


26.62 


29.59 


1.1172 


27.72 


30.97 


I. 1227 


28.82 


32.3s 


1 . 1063 


25.46 


28.17 


I.II18 


26.64 


29.61 


1. 1 1 73 


27-74 


31.00 


I. 1228 


28.84 


32.37 


1. 1064 


25.48 


28.19 


1 . III9 


26.66 


29.64 


1.1174 


27.76 


31.02 


I . 1229 


28.86 


32.40 


1.1065 


25.50 


28.22 


I . II20 


26.68 


29.67 


1.1175 


27.78 


31.05 


I • 1230 


28.88 


32.43 


I . 1066 


25.52 


28.25 


I . I I 21 


26.70 


29.69 


1.1176 


27.80 


31.07 


I.1231 


28.90 


32.45 


I . 1067 


25-54 


28.27 


I . II22 


26. 72 


29.71 


1.1177 


27.82 


31.09 


I. 1232 


28.92 


32.48 


1. 1068 


25.57 


28.30 


1 . II23 


26.75 


29.74 


1.1178 


27-84 


31.12 


I. 1233 


28.94 


32.50 


I . 1069 


25.59 


28.32 


I . II24 


26.77 


29.77 


1.1179 


27.86 


31.15 


I. 1234 


28.96 


32.53 


1. 1070 


25.61 


28.35 


I.IT2S 


26.79 


29.80 


1. 1 1 80 


27.88 


31.18 


1.123s 


28.98 


32.56 


I . 1071 


25.63 


28.38 


I . I 126 


26.81 


29.83 


1.1181 


27.90 


31 . 20 


I. 1236 


29.00 


32.58 


I. 1072 


25.65 


28. 40 


I.II27 


26.83 


29-85 


1.1182 


27.92 


31.23 


I. 1237 


29 .02 


32.60 


1. 1073 


25.67 


28.43 


I.II28 


26.85 


29.88 


1.1183 


27.94 


31-25 


I. I 238 


29.04 


32.63 


1.1074 


25.69 


28.45 


I . II29 


26.87 


29.90 


1.1184 


27.96 


31.27 


1.1239 


29. 06 


32.6s 


1.107s 


25.71 


28.48 


1.1130 


26.89 


29.93 


1.1185 


27.98 


31.30 


I . 1240 


29.08 


32-68 


1 . 1076 


25-73 


28.51 


I.II3I 


26.91 


29.95 


1.1186 


28.00 


31.32 


I . I 241 


29 . 10 


32-71 


1.1077 


25-75 


28.53 


I.II32 


26.93 


29.97 


1.1187 


28.02 


31.35 


I . 1242 


29. 1 2 


32-73 


1 . 1078 


25-78 


28.56 


I.II33 


26.9s 


30.00 


1.1188 


28.04 


31-37 


1.1243 


29.14 


32-76 


1.1079 


25.80 


28.58 


1.1134 


26.97 


30.02 


1.1189 


28.07 


31.40 


1.1244 


29. 16 


32.78 


I . 1080 


25.82 


28.61 


I. 113s 


26.99 


30.06 


I . 1190 


28.09 


31.43 


1.1245 


29.18 


32.81 


I.1081 


25.84 


28.64 


1.1136 


27.01 


30.08 


1.1191 


28.11 


31.4s 


1 . 1246 


29. 20 


32.83 


1 . 1082 


25.86 


28.66 


1.1137 


27.03 


30.10 


1 . 1 192 


28.13 


31.48 


I. 1247 


29. 22 


32.86 


1.1083 


25.89 


28.69 


1 . 1 1 38 


27.05 


30.13 


1.1103 


28.15 


31.51 


1.1248 


29.24 


32.89 


1 . 1084 


25.91 


28.72 


I. II 39 


27.07 


30.15 


1.1194 


28.17 


31.53 


I. I 249 


29.26 


32.91 


1.108s 


25.93 


28.75 


1 .1140 


27.09 


30.18 


1.1195 


28.19 


31.56 


1 - 1 250 


29.28 


32.94 


1. 1086 


25.96 


28.78 


1 . 1141 


27.11 


30.20 


I . 1196 


28.21 


31.59 


I.I251 


29.30 


32.96 


I . 1087 


25.98 


28.80 


I . 1142 


27.13 


30.22 


1.1197 


28.23 


31 .61 


1.1252 


29.32 


32-99 


1.1088 


26.01 


28.83 


1. 1 1 43 


27.15 


30.25 


1.1198 


28.25 


31.63 


1.1253 


29.34 


33.02 


I . 1089 


26.03 


28.86 


I. 1144 


27.17 


30.27 


I. 1199 


28.27 


31.65 


I. 1254 


29.36 


33.04 


1.1090 


26.05 


28.89 


1.H4S 


27.19 


30.31 


1 .1200 


28.28 


31.68 


I.12SS 


29.38 


33.57 


1 . 1091 


26.07 


28.92 


I . 1146 


27. 21 


30.33 


I. 1201 


28.30 


31.70 


1.1256 


29.40 


33.09 


1 . 1092 


26.09 


28.94 


1.1147 


27.23 


30.35 


1.1202 


28.32 


31.73 


1.I2S7 


29.42 


33.12 


1.1093 


26. 1 2 


28.97 


1.1148 


27.25 


30.37 


1.1203 


28.34 


31.75 


1.1258 


29.45 


33.14 


1 . 1094 


26. 14 


29.00 


1.1149 


27.27 


30.40 


1 . 1204 


28.36 


31.78 


1.1359 


29.47 


33.17 



ALCOHOLIC BEVERAGES. 



721 



Ex- 
tract 
in 

100 cc. 

Grams. 





OS 





OO'-i-Hi-iMf'N 


to 00 


PO 10 00 ro 
ro ro ro ro -I- -»- -t 


t^ 


1^ 


00 


0000000000000000 


00 00 


00 GO 00 00 00 00 CO 


1 





« 


« 



ro-tioo r— CO O^iN 


M P) 


rO -1- to vO t^ 00 On 


■Ex- 
tract 

in 
100 cc. 
Grams. 




00 






1- VO 


Ov " -1- r^ On « •+ 

r^ 00 00 CO CO Ov 0> 

t^ t^ j^ r^ f^ r~- t^ 


1 





" 


M 




rc -r "~; 'O r^ 00 O- 


M C) 


ro -t 10 vC l^ 00 Ov 


Ex- 
tract 

in 
100 cc. 
Grams. 


^ 






00 




wr0^00"^>00 

OOOOWMHHO) 


N to 


t^ PO to 00 <r) 

M ro ro ro ro Tt •* 


\o 


VO 





r^f^r— t^r^t^r^t^ 


1^ t^ 


r^ t-~ r^ r~- r-- t^ r^ 


1 





" 


M 




IS 


M N 


ro ■+ 10 vO t^ CO a. 




Ex- 
tract 
in 

100 cc. 

Grams. 




10 


00 


fDiOOO >-i i-OvOOO 




vO On M ^ NO On " 
t^ r^ 00 00 CO 00 On 


<i 


\o 


■0 


^ ^' ■o 


-o 


NO NO 'O NO 


1 





- 


ri 




'■'-. -t "-J t^ CC' On 


-H W 


ro -t to nO r- CO On 




Extract 

in 
100 cc. 
Grams. 


a^ 








ONOOOO>-K^M 


Ov M 


to r^ N to t^ 

M M ro ro rO rO ■^ 


irj 


10 


LO 


uoOvO^OOOO 


vO 


NO NO NO NO NO 


11^ 
i 





" 


N 




r/-, -i- U-; I^ OC 0. -1- 


M (N 


r^, -t- to t^ CO On 




Extract 

in 
100 cc. 
Grams. 




-t 


-1- 


-t 


r^ '•o 10 CO ri-i M-) 
-t- 1/-; 10 U-) to sC 


00 " 
t^ 


'•O nO CO *-■ '•0 nO On 

r^ t^ f^ 00 CO CO 00 


u-i 


Ul 


10 


10 10. to LO to to liO to 


to to 


to to 10 to to to to 


1 





« 


N 



rO'ti'^vO t^oO O^M 

M 


w P) 


r<N -^ to NO t^ CO On 


Extract 

in 
100 cc. 
Grams. 


00 

CO 


0-. 




c<: -< -+ nC " -t- 
O^OsOOOO-" 


r^ O^ 


PI -t r~~ On PI to r^ 

p) PI PI PI ro CO PO 


■:t 


^ 


^ 


-f-tioioioio'-oto 


to to 


to to to to to to to 


1 




On 

M 


- 


M 



rc-*>ovO r^oo O^O 


H 


ro ■* 10 NO t-~ 00 On 


Extract 

in 
100 cc. 
Grams. 


-i- 




-t 

4 


•+ 


to t^ <■' to r^ "-o 
-t -f to to to to vc 


to 00 


po u"' CO ►"! '^ ■<:> 
t>~ t^ r^ t^ CO oc CO 


^ 


Tt-t--*^-*-^-*-^ 


'i- 'i- 


•^ ■* rf Tf •* ^ -t 


1 




M 


M 


M 



(v^-j-to^O t^cO O^cC 


M M 


'•'■/ -t to r^ CO On 


Extract 

in 
100 cc. 
Grams. 




00 
00 


M 



co^OoO M -^^ Onm 
O-OnO^OOOOh- 


't vO 


On P) ^ r^ On P< ■^■ 
M PI P) « P< ro ~0 


r^j 


ro 


r^ 


ro^oro '*"<■'*'*••* 


-t >* 


'i- •* '^r 't 't ^ ■^■ 


1 



10 


M 


n 





M CI 


PO -* 10 NO t^ CO On 



72 2 FOOD INSPECTION AND ANALYSIS. 

mation to the truth is obtained, especially with beer high in sugar, by 
calculation as follows: 

From the Specific Gravity. — Evaporate a measured quantity of the 
beer to one-fourth its volume on the water-bath, make up with water 
to its original measure, and determine the specific gravity of the deal- 
coholized beer. Then by means of Schultz and Ostermann's table, pp. 
716-20, calculate the extract corresponding. 

From the Refraction. — Method of Ackermann and Foggenbiirg. 
— Determine the refraction of the liquor at 17.5° C. by means of the 
immersion refractometer. Determine also the refraction of the dis- 
tillate from 100 cc. of the liquor at 17.5° C. after making up to its original 
volume. In order to secure accurate results, care should be taken 
to cool the prism of the instrument to exactly 17.5° C. by immersing 
for five minutes in the water-bath previous to taking the refraction of 
the Hquids. If determinations are made on a number of samples, this 
cooling is not necessary except before taking the reading of the first of 
the series. 

Calculate the grams of extract (E) from the refraction of the liquor 
(R) and of the distillate {R') by the following formula: 

E = o.2S7os{R-R'). 

The extract is more conveniently obtained from Ackermann's table 
given on p. 721. 

Original Gravity of Beer Wort and its Determination. — Following a 
long-established custom of the English excise, the duty on beer has been 
based on the specific gravity of the original wort, by which is meant the 
wore of the beer before any of its sugar has been lost by fermentation. 

From the content of alcohol in the beer the sugar originally present 
in the wort may be calculated, assuming that the alcohol amounts to 
about half the sugar used up in fermentation. 

Obtain the specific gravity of the beer, dealcoholized and made up 
to its original volume, as in the calculation of the extract. This 
is called the "extract gravity." Note the specific gravity correspond- 
ing to the alcohol found, i.e., the specific gravity of the distillate in the 
alcohol determination, when made up to the original volume, and subtract 
this from i. The difference is known arbitrarily as the "degree of spirit 
indication." 

From the table of Graham, Hofmann, and Redwood,* p. 723, 
the "degrees of gravity lost" corresponding to the "spirit indication" 
* Report on Original Gravities, 1852; Allen's Com. Org. Anal., I., p. 136. 



ALCOHOLIC BEl^ERAGES. 



723 



are ascertained. This figure is added to the 
the "original gravity of the wort." 



extract gravity" to find 



SUGAR USED UP IN FERMENTATION. 

























Degrees 

' ' Spirii 
dicatio 


.0000 


O.OOOI 


.0002 


. 0003 


0. 0004 


0.0005 


0.0006 


0.0007 


0.0008 


0.0009 


. 000 . 




. 0003 


0.0006 


. 0009 


0.0012 


0.0015 


0.0018 


0.0021 


0.0024 


0.0027 


.001 


0030 


-0033 


.0037 


.0041 


.0044 


.0048 


- 005 1 


-0055 


.0059 


.0062 


.002 


0066 


.0070 


.0074 


.0078 


.0082 


.0086 


.0090 


.0094 


.9098 


.0102 


.003 


0107 


-OIII 


.0115 


.0120 


.0124 


.0129 


■O'^ii 


.0138 


.0142 


.0147 


.004 


0151 


-0155 


.0160 


.0164 


.0168 


.0173 


.0177 


.0182 


.0186 


.0191 


.005 


0195 


.0199 


.0204 


.0209 


.0213 


.0218 


.0222 


.0227 


.0231 


.0236 


.006 


0241 


.0245 


.0250 


-.0255 


.0260 


.0264 


.0269 


.0274 


.0278 


.0283 


.007 


0288 


.0292 


.0297 


.0302 


.0307 


.0312 


-0317 


.0322 


.0327 


-0332 


.008 


0337 


-0343 


.0348 


•0354 


-0359 


■0365 


.0370 


■0375 


.0380 


.0386 


.009 


0391 


-0397 


.0402 


.0407 


.0412 


.0417 


.0422 


.0427 


.0432 


-0437 


.010 


0442 


.0447 


.0451 


.0456 


.0460 


.0465 


.0476 


-0475 


.04S0 


.0485 


-Oil 


0490 


.0496 


.0501 


.0506 


.0512 


-0517 


.0522 


.0527 


•0533 


-0538 


.012 


0543 


.0549 


-<^554 


-0559 


.0564 


.0569 


-0574 


-0579 


.0:^84 


.0589 


.013 


0594 


.0600 


.0605 


.0611 


.0616 


.0622 


.0627 


•0633 


.0638 


.0643 


.014 


0648 


.0654 


-0659 


.0665 


.0471 


.0676 


.0682 


.0687 


.0693 


.0699 


.015 


0705 


.0711 


.0717 


.0723 


.0729 


•0735 


.0741 


.0747 


-0753 


•0759 



Example. — Suppose the "extract gravity" is 1.0389 and the specific 
gravity of the alcoholic distillate is 0.9902, both at 15.6. Then i —0.9902 = 
0.0098, the "degree of spirit indication." From the above table the cor- 
responding "degree of gravity lost" is found to be 0.0432. 

0.0432+1.0389 = 1.0821, the original gravity of the wort. 

The calculation in the above simplified form is accurate for normal 
beer wherein the free acid present, expressed as acetic, does not exceed 
0.1%. In case of beer that has developed free acid much in excess of 
the above limit, a correction should be added to the degrees of spirit 
indication. This correction, which in practice it is rarely necessary to 
apply except in extreme cases of old or sour beer, is calculated as follows: 

If a represents the grams of free acid (as acetic) in 100 cc, then the 
correction to be added to the spirit indication = 0.0013^ — 0.00014. 

Example. — Supposing the "extract gravity" to be 1-0413, the specific 
gravity of the alcoholic distillate to be 0.9890, and the free acid as acetic 
to be 0.35%. Then 1—0.989 = 0.0110, the degree of spirit indication. 

0,35X0.0013—0.00014=0.0003, correction to be added to the spirit 
indication. 

0.0110+0.0003=0.0113, corrected spirit indication. 



724 FOOD INSPECTION JND ANALYSIS. 

From the above table the corresponding degrees of gravity lost are 

0.0506 : 

0.0506+1.0413 = 1.0919, the original gravity of the wort. 
Determination of Degree of Fermentation. — ^This is calculated by 

200^ , . . . . 

the formula D = , in which Z) = degree of fermentation, ^=per cent 

B 

of alcohol by weight, and 5 = the original extract. 

Determination of Reducing Sugars. — Dealcoholize 25 cc. of the beer 
and make up to 100 cc. Determine reducing sugars by the Defren- 
O'Sullivan or Munson-Walker method, and calculate as maltose. 

Determination of Dextrin. — Dilute 50 cc. of the beer to 200 cc, 
hydrohzc by heating in a boiling water-bath for 2^ hours with 20 cc. 
of hydrochloric acid (specific gravity 1.125), nearly neutralize the free 
acid with sodium hydroxide, make up to 300 cc, filter, and determine 
the dextrose by copper reduction. Multiply the amount of reducing 
sugars as maltose by 0.95, subtract this from the dextrose, and multiply 
the difference by 0.9, thus obtaining the dextrin in the b?er 

Determination of Glycerin. — Proceed as directed on page 703 under 
wine. The milk of lime is added during evaporation after the carbon 
dioxide has been expelled. It is advisable that the filtrate, after being 
evaporated to a syrupy consistency, be treated again with 5 cc. of 
absolute alcohol and two portions of 7.5 cc. each of absolute ether. 
If clear, continue as directed. If not clear, it is necessary to repeat 

the treatment with lime. 

Determination of Total, Fixed, and Volatile Acids. — A measured 
volume of the beer, say 10 cc, is freed from carbon dioxide by bringing 
to boiling. It is then cooled and titrated with tenth-normal sodium 
hydroxide, using neutral litmus solution as an indicator. Each cubic 
centimeter of tenth-normal alkali is equivalent to 0.009 gram of lactic 
acid, in which the total acidity is usually expressed. 

Fixed acid, also expressed as lactic, though small quantities of suc- 
cinic, tannic, and malic acids are usually also present, is determined as 
follows: Dealcoholize a measured amount of the beer, say 10 cc, by 
evaporation to one-fourth its volume, dilute with water to the original 
volume, and titrate with tenth- normal alkali, as before. 

Volatile acid is expressed as acetic, and is usually calculated by dif- 
ference between total and fixed acid. Each cubic centimeter of tenth- 
normal alkali is the equivalent of 0.006 gram acetic acid. 



ALCOHOLIC BEVERAGES. 725 

Determination of Proteins. — Fifty cc. of the beer are first treated 
with 5 cc. of dilute sulphuric acid, and concentrated by boiling to syrupy 
consistency. Then proceed by the Gunning method, p. 69. Nx6.25 = 
j)roteins. 

Determination of Phosphoric Acid. — Unless the sample is very dark- 
colored, sufficiently close results can usually be obtained by direct titra- 
tion of the beer itself with uranium acetate solution. For very accurate 
results the ash should be used. Prepare a solution of uranium acetate of 
such strength that 20 cc. will correspond to o.i gram P^Og. This solution 
is best standardized against pure, crystallized, uneffloresced, powdered 
hydrogen sodium phosphate, 10.085 grams of which are dissolved in 
water and made up to a liter. 50 cc. of this solution contains o.i gram 
phosphoric anhydride, if the salt is pure. If the solution is of proper 
strength, 50 cc. evaporated to dryness and ignited in a tared platinum 
dish should have an ash weighing 0.1874 gram. For preliminary trial 
about 35 grams of uranium acetate are dissolved in water, 25 cc. of glacial 
acetic acid, or its equivalent in weaker acid added, and the solution made 
up to a liter with water. 

To standardize, 50 cc. of the standard phosphate solution prepared 
as above are heated to 90° or 100° C, and the uranium solution run in. 
from a burette till the resulting precipitate of hydrogen uranium phos- 
phate is complete. The end-point is determined by transferring a few 
drops of the solution to a porcelain plate, and touching with a drop of 
freshly prepared potassium ferrocyanide solution. When the slightest 
excess of uranium acetate has been added, a reddish-brown color is pro- 
duced by the ferrocyanide. The uranium acetate solution is purposely 
made rather stronger than necessary at first, and by repeated trials is 
brought by dilution with water to the required strength (20 cc. equivalent 
to 50 cc. of the phosphate solution). 

Fifty cc. of the beer are heated to 90° or 100° C. and titrated with 
the uranium acetate solution under the same conditions and in precisely 
the same manner as when standardizing that solution. Each cubic centi- 
meter of the uranium acetate corresponds to 0.01% of P2O5. 

For the phosphoric acid determination in the ash, 50 cc. of the beer 
are incinerated in the regular manner, and the ash moistened with con- 
centrated hydrochloric acid. The acid is then evaporated ofif on the 
water-bath, after which the ash is boiled with 50 cc. of distilled water, and 
titrated with the standard uranium solution. 



726 FOOD INSPECTION AND ANALYSIS. 

Determination of Carbon Dioxide.* — In the case of beer and other 
carbonated drinks put up in corked bottles, the carbon dioxide may be 
readily determined by piercing the cork with a metal champagne tap, 
which is connected by a flexible tube, first with a safety flask and then 
with an absorption apparatus somewhat after the style of that used in 
the determination of carbon dioxide in baking powder, the liberated 
carbon dioxide being absorbed for weighing in a concentrated solution 
of potassium hydroxide contained in a tared Liebig bulb. The beer- 
bottle thus connected is immersed in a vessel of water, which is heated 
over a gas-flame, after all the carbon dioxide that will escape spontaneously 
has been allowed to do so. Before weighing the absorbed carbon dioxide, 
the beer-bottle is replaced by a soda-lime tube, and a current of air drawn 
through the tubes. 

Beer and ale put up in bottles having patent metallic or rubber stoppers 
cannot thus be treated. In this case a measured quantity, say 200 cc, 
of the sample is transferred as quickly as possible to a large flask pro- 
vided with an outlet-tube having a glass stopper, this being connected 
up with the safety-flask and absorption-tubes. In this case heat may be 
directly, though cautiously, applied to the flask containing the beer by 
means of a gas-flame, after all the carbon dioxide has gone over that will 
do so spontaneously. Exactly the same apparatus as that shown in Fig. 
71 may be used to advantage for determination of carbon dioxide in beer, 
except that a larger distilling-flask should be used in the case of beer. 

Detection of Bitter Principles. — Elaborate schemes have been worked 
out for the systematic treatment of beer and ale for bitter principles. Nearly 
all of these are complicated and somewhat unsatisfactory. The presence 
of alkaloids in malt liquors, deliberately introduced during the process 
of manufacture, is now so rare that the analyst need seldom look for them, 
except in cases of suspected poisoning, when the scheme of Dragendorff 
or of Otto-Stas should be employed. While it is somewhat difficult to 
positively identify the various alkaloids, it is usually easy to prove their 
absence in clear solutions, if on treatment with either of the general 
alkaloidal reagents, Mayer's solution (Reagent No. 170), or iodine in potas- 
sium iodide (Reagent No. 143), no precipitate is formed. 

It is comparatively easy to prove the mere presence or absence of hop 
substitutes. The bitter principle of hops is readily soluble in ether, 
when a sample of the beer evaporated to syrupy consistency is extracted 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 95; Bui. 107 (rev.), p- 92. 
t Gerichtlich-Chemische Ermittelung von Giften, St. Petersburg, 1876. 



ALCOHOLIC BEl^ERAGES. 727 

therewith, while the bitters of quassia and aloes, common hop substitutes, 
are insoluble in ether. Though many varieties of bitters might be em- 
ployed that are soluble in ether, the absence of a bitter taste from the 
ether extract is evidence of the absence of hops. 

The most marked difference analytically between hops and their 
substitutes in malt liquors lies in the fact that the bitter principle of hops 
is completely precipitated therefrom by treatment of the beer with lead 
acetate (either basic or neutral), leaving no bitter taste in the filtrate 
after concentration, while if any of the hop substitutes are present, the 
concentrated filtrate from the lead acetate treatment will have a bitter 
taste. The excess of lead should be removed from the filtrate, before 
concentration and tasting, by treatment with hydrogen sulphide. If the 
residue from the ether or chloroform extraction of the concentrated filtrate 
from a beer after treatment with lead acetate be found to be bitter, there 
is positive evidence that a foreign substitute has been employed. 

The following are characteristic reactions that may help to identify 
some of the common hop substitutes.* 

Quassiin is readily soluble by chloroform from acid solution. If a 
residue containing quassiin be moistened with a weak alcoholic solution 
of ferric chloride and gently heated, a marked mahogany-brown color- 
ation is produced. 

On treatment of quassiin with bromine and sodium hydroxide or 
ammonia, a bright-yellow color is shown. 

Chiretta is readily dissolved by ether from its aqueous solution. Its 
ether residue, when treated with bromine and ammonia, gives a straw 
color, slowly changing to a dull purple-brown. This is not true of 
its chloroform residue, so that it is not to be mistaken for quassia 
(Allen). 

Gentian Bitter may be extracted by treatment of the acid liquor with 
chloroform. When the residue containing gentian bitter is treated with 
concentrated sulphuric acid in the cold, no color is produced, but on 
warming gently a carmine-red color is shown; if further treated with 
ferric chloride solution, a green-brown color is formed. 

Aloes. — ^This substance is separated from beer by treating the dried 
residue from 200 cc. of the beer with warm ammonia, filtering, cooling, 
and treating the filtrate with hydrochloric acid. The resin of aloes is 
precipitated and collected on a filter. It is insoluble in cold water, ether, 

* Allen, Analyst, 12, 1887, p. 107. 



y28 h'OOD INSPECTION AND ANALYSIS. 

chloroform, or petroleum ether, but is soluble in alcohol. It has a very- 
characteristic odor, which serves to identify it. The hot-water solution 
gives a curdy precipitate on treatment with lead acetate. 

Capsicin is extracted by treatment of the acid liquor with chloroform. 
It is recognizable by its sharp, pungent taste. 

Detection of Arsenic. — By the Marsh Method. — Measure loo cc. of 
the beer (freed from carbon dioxide by agitation) into a seven-inch porce- 
lain evaporating-dish, add 20 cc. pure concentrated nitric acid, and 3 cc. 
pure concentrated sulphuric acid, and cautiously heat till vigorous chemi- 
cal action sets in, accompanied by frothing and swelling of the beer. Turn 
the flame low or remove it altogether, and stir vigorously till the frothing 
ceases, after which the liquid may be boiled freely. At this stage 
transfer to a large casserole, and continue the boiling till nearly all 
the nitric acid is driven off. Then, holding the casserole by the handle, 
continue the heating till the mass chars and the fumes of sulphuric acid 
are given off, giving the casserole a rotary motion to prevent sputtering. 
The residue should be reduced to a dry, black, pulverulent char soon after 
the sulphuric acid fumes begin to come off freely. If still liquid, pieces of 
filter-paper should be stirred in while still heating, till the residue is dry, 
avoiding an excess of paper. 

Cool, add 50 cc. of water, and remove the masses of char from the sides 
of the dish by the stirring-rod. Heat to boiling and filter. Use the 
filtrate for the Marsh apparatus, adding it gradually. 

The arsenic mirror may be weighed in the usual manner, if of suffi- 
cient size. 

Reinsch's Test."^ — Two hundred cc. of the beer are acidified with i cc. 
of pure, concentrated, arsenic-free hydrochloric acid, and evaporated to 
half its volume. 15 cc. more of hydrochloric acid are then added, and 
a piece of pure burnished copper foil half an inch long and a quarter of 
an inch wide is immersed in the liquid and kept in it for an hour while 
simmering, replacing from time to time the water lost by evaporation. If 
after the lapse of an hour the copper still remains bright, no arsenic is 
present. 

If the copper shows a deposit, remove, wash with water, alcohol, and 
ether, and diy. Then place the copper in a subliming-tube, and heat 
over a low flame. Tetrahedral crystals, apparent under the microscope, 
show the presence of arsenic. Blackening of the copper does not in itself 
prove arsenic. 

* Jour. Soc, Chem Ind., 20, p. 646. 



ALCOHOLIC BEVERAGES. 



729 



Detection and Determination of Preservatives. — See Chapter XVITI. 
Sulphurous acid may be determined by direct titration, as in the case of 
wine. 

MALT EXTRACT. 

True malt extract is a syrupy fluid having a specific gravity of from 
1.3 to 1.6, and made up in accordance with the following directions of 
the 1880 Pharmacopoeia: Upon 100 parts of coarsely powdered malt 
contained in a suitable vessel, pour 100 parts of water, and macerate 
for six hours. Then add 400 parts of water, heated to about 30° C. 
and digest for an hour at a temperature not exceeding 55° C. Strain 
the mixture with strong pressure. Finally, by means of a water-bath or 
vacuum apparatus, at a temperature not exceeding 55° C, evaporate 
the strained liquid rapidly to the consistence of thick honey. 

Keep the product in well-closed vessels in a cool place. 

Such an extract has a residue of at least 70%, consisting chiefly of 
maltose, and contains about 2% of diastase. It should furthermore be 
capable of converting its own weight of starch at 55° C. in less than ten 
minutes. 

The following are analyses of three samples of pure malt extract :* 











•o.a 












_u 


















































c 


< 


(A 
W 




f3. 




"3 


u 
y, 
Q 


< 


A 


I-,S87 





72.31 


0.231 


0.033 


3-329 


62.52 


5-25 


I. 21 


0.483 


h 


1 .421 





76.65 


0.275 


0.021 


3. 116 


65.41 


6.94 


I. 19 0.556 


c 


1.498 





79.81 


0.386 


0.05314.872 


61.32 


12.39 


1.230.428 



Diastatic Action. 



Complete in less than 5 min. 
" " " 10 " 
" " " 5 " 



There are on the market many so-called malt extracts widely advertised 
for their tonic and medicinal virtues, having the taste and consistency 
of beer or ale. In fact they are virtually beer, differing therefrom mainly 
in respect to price. Such "malt extracts" have no diastase, and their 
value as nutrients depends almost entirely on their sugar content. 

Harrington! has analyzed twenty-one of the best known of these 
alleged malt extracts, the maximum, minimum, and mean results of his 
analyses being as follows: 



* Penn. Dept. of Agric. An. Rep., 1898, p. 85. 

j" Boston Medical and Surgical Journal, Dec. 31, li. 



730 



FOOD INSPECTION AND ANALYSIS. 





Specific 
Gravity. 


Alcohol. 


Total 
Residue. 


Ash. 




1-0555 
I. 0149 


7-13 
0.74 

3-94 


13-63 
5-13 
8.78 


0-53 
0.20 


Minimum. 


Mean 









None of them contained any diastase, and several were preserved 
with salicylic acid. 

DISTILLED LIQUORS. 

These beverages differ from those hitherto considered, by reason of 
their high alcoholic content and low extract or residue. Indeed, when 
first distilled they are entirely without residue, but from long storage in 
casks, they absorb certain extractives from the wood, that impart more 
or less flavor as well as color. 

When any fermented alcoholic infusion is subjected to distillation 
under ordinary circumstances, a distillate results which consists of a 
mixture with water of a large number of alcohols, chief among which 
is ethyl alcohol. The high boiling alcohols — amyl, butyl, propyl, etc., 
with their esters — exist in the distillate in small amount, constituting 
what is known as fusel oil. The various distilled liquors of commerce 
are made by just such a process of distillation, the product varying widely 
in flavor and character with the basis from which it was distilled. 

The so-called pot-still (the old-fashioned copper still and worm) 
is well adapted for the production of potable spirits such as whiskey, 
brandy, gin, and rum, as these products should contain the congeneric 
substances which give the liquors their special character; it is not, 
however, suited for the manufacture of pure alcohol, because repeated 
distillation would be required for purification. 

Now, however, by the use of improved apparatus, such as the Coffey 
still, involving the principle of fractional condensation, it is possible to 
obtain what is known as " silent spirit," or ethyl alcohol, free from 
fusel oil. With proper appurtenances for rectifying, one can now obtain 
95% alcohol by two distiflations. 

Standards for Spirits. — The following are the standards adopted 
by the Joint Committee of the Association of Official Agricultural 
Chemists and the Association of State and National Food and Dairy 
Departments: 

Distilled Spirit is the distillate obtained from a fermented mash of 
cereals, molasses, sugars, fruits, or other fermentable substance, and 



y4LC0H0LIC BEVERAGES. 



731 



contains all the volatile flavors, essential oils, and other substances 
derived directly from the material used, and the higher alcohols, ethers, 
acids, and other volatile bodies congeneric with ethyl alcohol produced 
during fermentation, which are carried over at the ordinary tempera- 
ture of distillation, and the principal part of which are higher alcohols 
estimated as amylic. 

Alcohol, Cologne Spirit, Neutral Spirit, Velvet Spirit, or Silent Spirit, 
is distilled spirit from which all, or practically all, of its constituents 
except ethyl alcohol and water, are separated, and contains not less than 
94.9% (189.8 proof) by volume of ethyl alcohol. 

Composition of Fusel Oil. — Fusel oil varies considerably in compo- 
sition with the source from which it is derived. Amyl alcohol, being 
in all cases its chief constituent, is frequently known commercially as 
fusel oil. The alcohols found in fusel oil with their formulas, specific 
gravity, and boiling-points are as follows: 



Formula. 




Boiling-point. 



Ethyl alcohol. 
Propyl ' ' 
Butvi " . 
Amyl " . 
Hexyl " . 



C2H5OH 
C,H,OH 
C.HgOH 
CjH^OH 
CflH„OH 



78.4° C. 
97° C. 
115° C. 

130° c. 



The following acids have been found in fusel oil, usually combined 
with the alcohols to form compound ethers: 



Acetic HC2H3O2 

Propionic HC3H5O2 

Butyric HC.H.O^ 

Valerianic HCjHgOa 



Caproic HCeHuOj 

(Enanthylic HC7H13O3 

Caprylic HCgHisOz 

Pelargonic HCaHi^Os 



Aging. — Freshly distilled liquors all contain notable quantities of 
fusel oil, which renders them harsh and unfit for use, but by the process 
of aging, they become in several years mellow and palatable. The chemi- 
cal changes which take place during aging are discussed under whiskey. 



WHISKEY. 



Process of Manufacture. — Whiskey is the liquor resulting from the 
distillation of a fermented infusion of grain, the process being carried 
out in a pot-still, or some other form of still, constructed so that the 
resulting liquor contains not only the alcohol, but also the greater part 



732 FOOD INSPECTION /tND /1N/1 LYSIS. 

of the congeneric substances which are vaporized with the alcohol. The 
fermented infusion known as the "mash" is obtained by steeping in 
water the starch-containing material, usually barley, rye, corn (maize), 
or oats mixed with malt, and subjecting the mixture to the action of 
the diastase contained in the malt, in much the same manner as the 
mashing process in the brewing of beer, except that for whiskey the 
process of saccharous fermentation is carried further, with a view to 
obtaining a maximum yield of maltose and a minimum of dextrin. 
Yeast is afterwards added, and alcoholic fermentation allowed to proceed 
with proper precautions. 

Genuine Scotch whiskey is made from malt which has been dried 
over peat, thus imparting a smoky taste to the liquor. Malt alone is 
seldom used in other whiskies; more often the grain most abundant 
in the locality where the whiskey is distilled forms the basis of the 
liquor. Bourbon whiskey (made originally in Bourbon County, Ken- 
tucky) is made from a mixture of grain, 50 to 60 per cent of which is 
corn, 10% malt, and the balance rye. 

Corn alone mixed with malt is employed in some localities, and pure 
rye whiskey is made from rye and malt. 

The fermented wort from whatever source obtained is subjected to 
distillation, purposely avoiding rectification or separation of the fusel 
oil and other congeneric substances which are valuable as flavors. The 
product of the first distillation is called " low wines," and is redistilled; 
the product of the second distillation is commonly divided into three 
fractions, of which the middle portion, or " clean spirit " is retained 
for the whiskey, while the first (" foreshots ") and the last fraction 
("faints") are mixed with the next portion of low wine to be redistilled. 
If the whiskey is too high in alcohol, it is diluted to the proper 
strength. 

As new whiskey is crude and harsh in taste, it is subjected to " aging," 
or storing in casks for a number of years. The aging process softens 
and refines the flavor, but recent investigations have proved that this 
is not due, as formerly believed, to transformation of fusel oil into esters 
(ethers). The esters increase in amount during aging, as do also the acids 
— especially the volatile acids — the aldehydes, and the furfural. As a 
matter of fact, the percentage of fusel oil increases instead of diminishes 
on aging, due to the evaporation of water and, in a lesser degree, of 
alcohol through the wood; the actual amount, however, remains prac- 
tically the same as at the start (see table, p. 737). When first distilled, 



ALCOHOLIC BEVERAGES. 733 

whiskey is perfectly colorless, but during the aging it extracts more or 
less color and some flavor from the casks in which it is stored. This 
color is especially pronounced in American whiskies, owing to the pre- 
vailing custom of charring the inside of the cask. Its flavor varies 
considerably with the nature of the grain used in its preparation. 

U. S. Rulings. — The following decision of President Roosevelt, based 
on an opinion of Attorney- General Bonaparte, was promulgated by Sec- 
retary Wilson, April ii, 1907:* 

" Straight whiskey will be labeled as such. 

" A mixture of two or more straight whiskies will be labeled ' blended 
whiskey,' or ' whiskies.' 

" A mixture of straight whiskey and ethyl alcohol, provided that 
there is a sufficient amount of straight whiskey to make it genuinely a 
* mixture,' will be labeled as compound of, or compounded with, pure 
grain distillate. 

" Imitation whiskey will be labeled as such." 

Joint Standards. — The following are the standards of the Joint Com- 
mittee of the A. O. A. C. and the A. S. N. F. D. D.: 

New Whiskey is the properly distilled spirit from the properly pre- 
pared and properly fermented mash of malted grain, or of grain the starch 
of which has been hydrolyzed by malt; it has an alcoholic strength 
corresponding to the excise laws of the various countries in which it is 
produced, and contains in 100 liters of proof spirit not less than 100 grams 
of the various substances other than ethyl alcohol derived from the grain 
from which it is made, and of those produced during fermentation, 
the principal part of which consists of higher alcohols estimated as 
amylic. 

Whiskey {Potable Whiskey) is new whiskey which has been stored 
in wood not less than four years without any artificial heat save that 
which may be imparted by warming the storehouse to the usual tem- 
perature, and contains in 100 liters of proof spirit not less than 200 grams 
of the substances found in new whiskey, save as they ar2 changed or 
eliminated by storage, and of those produced as secondary bodies during 
aging; and, in addition thereto, the substances extracted from the casks 
in which it has been stored. It contains, when prepared for consumption 

* While this decision seems to be in accord with the spirit of the Food and Drugs Act, 
it is liable to modification, since it is naturally not universally satisfactory. Indeed a per- 
manent ruling, acceptable to all interests, as to what constitutes pure whiskey is extremely 
diflBcult to imagine. 



734 FOOD INSPECTION y4ND /IN A LYSIS. 

as permitted by the regulations of the Bureau of Internal Revenue, not 
less than 45% by volume of ethyl alcohol, and, if no statement is made 
concerning its alcoholic strength, it contains not less than 50% of ethyl 
alcohol by volume, as prescribed by law. 

Rye Whiskey is a whiskey in the manufacture of which rye, either 
in a malted condition or with sufficient barley or rye malt to hydrolyze 
the starch, is the only grain used. 

Bourbon Whiskey is a whiskey made in Kentucky from a mash of 
Indian corn and rye, and barley malt, of which Indian corn forms more 
than 50%. 

Corn Whiskey is whiskey made from malted Indian corn or of 
Indian corn the starch of which has been hydrolyzed by barley malt. 

Blended Whiskey is a mixture of two or more whiskies. 

Scotch Whiskey is whiskey made in Scotland solely from barley malt, 
in the drying of which peat has been used. It contains in 100 liters of 
proof spirit not less than 150 grams of the various substances prescribed 
for whiskey exclusive of those extracted from the cask. 

Irish Whiskey is whiskey made in Ireland, and conforms in the 
proportions of its various ingredients to Scotch whiskey, save that it may 
be made of the same materials as prescribed for whiskey, and the malt 
used is not dried over peat. 

U. S. P. Standards. — The requirements for whiskey are as follows: 
It should be at least two years old; in specific gravity it should lie 
between the hmits of 0.945 and 0.924; its alcohohc content should be 
not less than 37% nor more than 47.5% by weight; the residue from 
100 cc. should be not more than 0.5 gram, which should be neither sweet 
nor spicy, should dissolve in 10 cc. of cold water, and this solution should 
be colored only a pale green when treated with a drop of very dilute 
ferric chloride solution (a deeper color would indicate more than traces 
of tannin). In evaporating the liquor on the water-bath for the residue, 
the last traces volatilized should have an agreeable odor free from harsh- 
ness, indicative of the absence of fusel oil. Its reaction should be slightly 
acid, but not more than 1.2 cc. of normal alkali should be required to 
neutralize 100 cc. of the liquor, using litmus as an indicator. If 50 cc. 
are shaken vigorously with 25 grams of kaolin, allowed to stand an hour 
and filtered, the color of the filtrate should not be mucli lighter than 
before treatment. 

Composition. — Whiskey consists chiefly of alcohol and water, with 
relatively small amounts of fusel oil, acids, esters, aldehydes, and fur- 



.4LCOHOLIC BEVERAGES. 



735: 



fural. Its extract, derived mainly from the casks in which it is stored, 
should consist only of small amounts of tannin, sugar, and coloring 
matter. 

British Whiskies. — Scotch and Irish whiskies are aged in uncharred 
barrels, hence they are of a lighter color than the American product. 
Scotch whiskey is further characterized by its smoky taste, due to the 
peat over which it is dried. The following analyses by Vasey * illustrate 
the composition of Scotch and Irish whiskey of different ages, of neutral 
spirits used in compounding (" blending ") and adulterating, and of 
the compounded liquors: 



Grams per loo Liters. 



Volatile 

Acids. 



Esters. 



Alde- 
hydes. 



Furfural. 



Fusel Oil. 



Pot-still Scotch whiskey, 8 years old . 
Pot-still Scotch whiskey, 25 years old 

Irish whiskey, new 

Irish whiskey, 7 years old 

Neutral spirit for "blending" 

" Blended " Scotch 

"Scotch," probably all neutral spirits 



48.0 
64.8 
20. 9 
41 .8 
8.4 
39-1 
16.8 



89-7 
125. 1 

7-7 
20.9 

2,S-8 

106.8 

8.2 



14.2 
66.1 

6.5 
1 1 . 2 

4-9 
14-3 
10. o 



4.0 
5-4 
0.4 
3-4 
0.4 

3-5 
none 



200.0 
180.0 
174.0 
204.0 
trace 
108. 5 
none 



It will be noted that the congeneric substances in whiskey increase 
on aging, although in the case of fusel oil this apparent increase is 
doubtless due merely to concentration dependent on evaporation. The 
sample of neutral spirits contained only small amounts of the congeneric 
substances, while the " blended " whiskies were deficient in most of 
these substances. 

American Whiskies. — These have a deeper color than the British 
whiskies (due to the charred barrel) and a rich fruity flavor without 
the suggestion of smoke. 

In the table on p. 736 are given analyses by Shepard f of fourteen 
leading brands, including both rye and bourbon, varying in age from 
four to eight years; also of two samples of neutral spirits used for com- 
pounding and adulterating. 

A summary of the results obtained by Crampton and Tolman \ in 
the analysis of fourteen brands of rye and seventeen brands of bourbon 
whiskey at differing stages of aging appear in the table on page 737. The 
barrels were kept in U. S. bonded warehouses during aging, and samples 

* Potable Spirits, pp. 82, 83, and 87. 

t The Constants of Whiskey, S. Dak. Food and Dairy Commission, March, 1906. 

% Jour. Am. Chem. Soc, 30, 1908, p. 98. 



736 



FOOD INSPECTION /tND ANALYSIS. 



Rye 

Bourbon 

Standard 

Hand-made sour mash. 

Hand-made sour mash. 
Hand-made sour mash. 



Bourbon 

Special reserve 
Sour mash ... 



Neutral spirits. 



5 

Ah 

4 

4 

6 

6 

7 

5i 

7 

5 

1\ 

4 



fee 



50-1 

SO- 1 
50.0 

49-8 

50.2 

49-9 

50.4 

50 

50 

49-9 

49-8 

50.1 

49-8 

50-1 

95-6 

94-4 



Grams per 100 Liters. 



189. 
181, 
160, 
162 
148. 
132 
138, 

153 
180 
129 
212 
124 
177 
139 



10-3 
3-- 



Acids. 



92.0 
68.4 
66.8 
67.1 
62.4 
49-2 
74-8 
58.8 

74-4 
60.9 

93-0 
58.2 
66.5 
50.3 
7-5 
6.-, 



12.8 

9-3 
10.2 
10.2 

7-5 
7-5 
8.6 

9-9 
9-9 

7-2 

13-5 
7.2 
9.0 

6.3 
1 .2 

1-4 



79-2 

59-1 
56.6 

56.9 
54-9 

41-7 
66.2 

48.9 
64-5 
53-7 
79-5 
51-0 
57-5 
44.0 

6-3 
4-9 



60.7 

55-9 
74-8 
55-9 
39-6 
61.6 
69.6 
70.8 

49-3 
94.0 
64.0 
76.6 
54-6 
15-4 
64. 2 



17-5 
17-S 
10. o 
12.0 
15.0 
8.0 

10-5 
14.0 

12.5 

9-5 

22.5 

9-5 
10. o 

7-5 

2-5 

II .0 



3-0 
3-2 
2.4 
2.6 
2.6 
1 .0 

1-3 

0.7 

2.5 
0.8 

5-0 
0.5 
1-7 
1-5 



84.9 
102.6 
160.4 
130.9 
152.0 
107.4 
192.7 

I37-I 

117. o 

141. 7 

II9-5 

95-3 

193.6 

152.0 

30.0 

39-6 



were withdrawn at intervals of a year for eight years. As the minimum 
figures for certain constituents are abnormal, the next to the minimum 
figures are also given. It will be noted that during the first few years 
there was a marked increase in actual amounts of all the constituents 
determined, except fusel oil, over and above that due to concentration, 
but after three or four years the acids and esters do not materially 
change. The rye whiskies contained larger amounts of sohds, acids, 
esters, etc., than the bourbons, but this was attributed to the fact that 
heated warehouses are used for rye, and unheated for bourbon whiskey. 
The authors state that the characteristic aroma of American whiskey, 
also the oily appearance and the " body " (solids), are due to the charred 
barrels. 

Thirty-seven samples of whiskey, purchased by the glass from various 
Massachusetts saloons, were examined by the Massachusetts State 
Board of Health in 1894, with the following results: 





Per Cent 

Alcohol by 
Weight. 


Per Cent 

Extract. 


Maximum 


45-96 
30.70 

36-51 


1.68 
0.08 
0.50 


Minimum 


Mean 





ALCOHOLIC BEVERAGES. 737 

SUMMARY OF ANALYSES OF AMERICAN WHISKIES OF DIFFERENT AGES 





Proof. 


Grams per 100 Liters of 100 Proof Spirits. 






















Color 


Extract. 


Acids. 


Esters. 


Alde- 
hydes. 


Fur- 
fural. 


Fusel 
Oil. 


Rye Whiskey. 


















New: Average . .. 


101.2 


0.0 


13.3 


4.4 


16.3 


5.4 


1.0 


90.4 


Maximum . 


I02.0 


0.0 


30.0 


72.0 


21.8 


15.0 


1.9 


161. 8 


Minimum * 


lOO.O 


0.0 


5-0 


12.0 


4.3 


0.7 


trace 


r 61.8 

I 43-7 


One year old: Average . .. 


102.5 


8.8 


119.7 


46.6 


37.0 


7.0 


1.8 


111.5 


Maximum . 


104.0 


13-8 


171. 


60.5 


64.8 


15-5 


3-3 


194.0 


Minimum * 


lOI.O 


/ 7.2 
{ 6.6 


93-0 
92.0 


31-1 
5-8 


6.8\ 
6.8/ 


2.8 


0.4 


r 80.4 
1 66.4 


Two years old: Average... 


104.9 


11.6 


144.7 


51.9 


54.0 


10.5 


2.2 


112.4 


Maximum . 


109.0 


16.7 


199.0 


75.6 


75-1 


18.7 


5-7 


214.0 


Minimum * 


100. 


r 8.8 

\ 8.6 


121. 
94.0 


44-3 
II .0 


4i-5\ 
31-2/ 


5-4 


:o.7 


/ 83.4 
I 82.2 


Three years old: Average . .. 


107.7 


13.2 


171.4 


62.7 


61.5 


12.5 


1.5 


112.7 


Maximum . 


112. 


18.3 


224.0 


81.8 


79-8 


20.8 


6.1 


202.0 


Minimum * 


104.0 


/ II. 4 
\ 10. 1 


145-0 
119. 


52-3 
16.4 


47-61 
34-3 J 


6-5 


0-7 


f 79.0 
\ 60.0 


Four years old: Average... 


111.2 


14.0 


185.0 


65.9 


69.3 


13.9 


2.8 


125.1 


Maximum . 


118. 


18.9 


238.0 


83.8 


89.1 


22.1 


6-7 


203-5 


Minimum * 


105.0 


r II. 6 
I11-3 


156-0 

153-0 


58.6 
17-3 


57-71 
36.3/ 


6.4 


0.7 


r 83.8 
I 67-8 


Eight years old: Average . .. 


123.8 


18.6 


256.0 


82.9 


89.1 


16.0 


3.4 


154.2 


Maximum . 


132.0 


24.2 


339-0 


112. 


126.6 


26.5 


9-2 


280.3 


Minimum * 


112. 


/13-8 


214.0 


73-7 


68.4 1 
40.9/ 


7-9 


o.S 


r 109.0 
\107.1 






\i3-7 


200.0 


31-7 






Bourbon Whiskey. 


















New: Average . .. 


101.0 


0.0 


26.5 


10.0 


18. 4 


3.2 


0.7 


100.9 


Maximum . 


104.0 


0.0 


161. 


29.1 


53-2 


7-9 


2.0 


171-3 


Minimum * 


lOO.O 


0.0 


4.0 


12.0 


13.0 


I.O 


trace 


[ 71-3 

I 42-0 

110.1 


One year old: Average . .. 


101.8 


7.1 


99.6 


41.1 


28.6 


5.8 


1.6 


Maximum . 


103.0 


10.9 


193-0 


55-3 


55-9^ 


8.6 


7-9 


173-4 


Minimum * 


100. 


/ 5-4 
I 4-6 


61.0 
54-0 


24-7 

7-2 


17. 2I 
10.4 J 


2-7 


trace 


[ 58.0 
I 42.8 


Two years old : Average . . . 


102.2 


8.6 


126.8 


45.6 


40.0 


8.4 


1.6 


108.9 


Maximum . 


104.0 


II. 8 


214.0 


61.7 


59.8 


12.0 


9.1 


197. 1 


Minimum * 


100. 


f 6.9 

I 5-7 


81.0 
78.0 


25-5 
23-3 


24-41 
II. 2 j 


5-9 


0.4 


/ 86.2 
I 42-8 


Three years old: Ave;rage . .. 


103.0 


10.0 


149.3 


54.3 


48.1 


10.5 


1.7 


112.4 


Maximum . 


106.0 


13.8 


245-0 


64.8 


73-0 


22.1 


9-5 


221.8 


Minimum.* 


100. 


r 8.9 

I 7-0 


95-0 
90.0 


38-4 
32.1 


27-2I 
12.1/ 


5-9 


0.6 


f 88.0 
I 43-5 


Four years old: Average . . . 


104.3 


10.8 


151.9 


58.4 


53.5 


11.0 


1.9 


123.9 


Maximum . 


108.0 


14.8 


249.0 


73-0 


80.6 


22.0 


9.6 


237-1 


Minimum * 


100. 


r 8.6 

I 7-4 


lOI.O 

92.0 


40.4 
40.4 


28.2 1 
13-8/ 


6.9 


0.8 


/ 95-0 

I 43 --5 


Eight years old : Average . . . 


111.1 


14.2 


210.3 


76.4 


65.6 


12.9 


2.1 


143.5 


Maximum . 


124.0 


20.9 


326.0 


91.4 


93-6 


28.8 


10. 


241.8 


Minimum * 


102.0 


/ 12.3 

I IO-5 


152.0 
141. 


64.1 

53-7 


37-7\ 
22.1 J 


8-7 


1.0 


/ IIO.O 

I 47.^ 



* Minimum and next to the minimum. 



738 FOOD INSPECTION AND ANALYSIS. 

Seven of these samples had an excess of tannic acid, three had no 
tannic acid at all, and two or three had insoluble residues. 

Adulteration of Whiskey. — Imitation whiskey is often concocted by 
diluting alcohol or neutral spirit to the proper strength, coloring with 
caramel, sometimes adding for body prune juice, and adding for flavor 
certain essential oils, such as oil of wintergreen, and artificial fruit 
essences, such as oenanthic and pelargonic ethers. As a rule, a small 
amount of pure whiskey is mixed with the artificial to give it flavor. 

What has long been known as " blended whiskey " is either an 
imitation pure and simple, or a compound of whiskey and neutral spirits, 
artificially colored and flavored. According to the U. S. decisions, 
the term " blended whiskey " is restricted to a mixture of dift'erent 
kinds of genuine whiskey, colored and flavored. 

Among Fleischman's recipes for " blended " whiskey is the following, 
which he claims to be the very lowest grade: 

Spirits 32 gallons 

Water 16 

Caramel 4 ounces 

Beading oil i ounce 

"Beading oiP' is prepared by mixing 48 ounces oil of sweet almonds 
with 12 ounces C. P. sulphuric acid, neutralizing with ammonia, adding 
double the volume of proof spirits, and distilling. This preparation is 
so called because it is largely used for putting an artificial bead on cheap 
liquors. 

A little creosote is sometimes added to give a burnt taste in sem- 
blance of Scotch whiskey. Pungent materials such as cayenne pepper 
are said to be used as adulterants, but no record is known of any substance 
being used more injurious than the alcohols. Sugar is a frequent adul- 
terant. 

Some doubt exists as to the injurious effects of fusel oil on the sysiem. 

The following analyses by Ladd * show the composition of neutral 
spirits, and imitation whiskey consisting of neutral spirits diluted with 
water, colored with caramel and flavored: 

* N. Dak. Agric. Exp. Sta. Rep., 1906, Part II, p. 145. 



ALCOHOLIC BEVERAGES. 



739 





c 

(U 

O 

< 


Grams per 100 Liters. 






< 


Acids. 


0) 


3. 

X.' 

< 


"5 






"c5 



J) 


"0 
> 





Neutral spirits 


g4.c 
40.1 

45-8 
4S-0 


2.4 
^66. 4t 

854. of 
456. of 


0.0 

4-4 

2.0 

5-5 


7-2 

43-2 

20.4 

9-6 


0.0 
9.0 
3-0 
3-0 


7-2 

34-2 

17-4 

6.6 


26.4 

3-5 
14.0 

5-2 


6.0 
trace 
trace 
trace 


trace 
0.4 

I.O 

0.8 


28.0 

37-0 
42.3 


Imitation whiskey, rye 

" " malt . . . . 
" " rye 



t Includes caramel color. 



BRANDY AKD COGNAC. 



Brandy is the product of the distillation of fermented grape juice or 
wine. In a broader sense the term brandy is sometimes applied to liquor 
distilled from the juices of other fruits, such as apples, peaches, cherries, 
etc. The finest grades of brandy, such as pure cognac and armagnac 
(named from towns in France in which they were originally distilled), 
are made from choice white wine by the use of pot stills, and naturally 
command a high price. Brandy of a lower grade is distilled from the 
cheaper wines, and sometimes from the fermented marc, or refuse, of the 
grape, as well as from the lees and "scrapings" of the casks. The best 
brandies are sometimes rectified by a second distillation. Like whiskey, 
the fresh brandy is colorless, and would so remain if stored in glass or 
stone. The color is due to the wooden casks in which it is stored. Brandy 
consists of nearly pure alcohol and water, having a characteristic flavor, 
differing somewhat according to the nature and quality of the wine from 
which it was prepared. The chief flavor of pure cognac is due to oenan- 
thic ether. 

Composition. — Vasey gives the following analyses of cognac and 

of brandy adulterated with neutral spirits: 

Ten Year-^Old Brandy Mixed with Neutral Spirits. 

Volatile acids 74-5 79-4 grams perioo liters. 

Esters io9-3 32-4 " " 

Aldehydes 16.6 7.4 " " 

Furfural 1.7 0.6 " " 

Fusel oil 124.2 49 -o " " 



* Analysis of Potable Spirits, p. 20. 



740 



FOOD INSPECTION ^ND ANALYSIS. 



Thirty-seven samples of brandy, collected from Massachusetts bar- 
rooms in 1894 and examined by the State Board of Health, showed the 
following results: 





Per Cent 

Alcohol by 

Weight. 


Per Cent 
Extract. 




50.70 
21.30 
40-54 


3.00 
O.IO 

0-93 


Minimum 


Mean 





Three of these samples were artificially prepared mixtures of alcohol 
and water, one showed the presence of cloves, five contained tannin in 
excess, nine were excessively acid, and two had insoluble residues. 

Joint Standards. — The following are the standards of the A. O. A. C. 
and the A. S. N. F. D. D.: 

New Brandy is a properly distilled spirit made from wine, and 
contains in 100 liters of proof spirit not less than 100 grams of the 
volatile flavors, oils, and other substances, derived from the material 
from which it is made, and of the substances congeneric with ethyl alcohol 
produced during fermentation and carried over at the ordinary tem- 
peratures of distillation, the principal part of which consists of the 
higher alcohols estimated as amy lie. 

Brandy {Potable Brandy) is new brandy stored in wood for not less 
than four years without any artificial heat save that which may be 
imparted by warming the storehouse to the usual temperature, and 
contains in 100 liters of proof spirit not less than 150 grams of the sub- 
stances found in new brandy, save as they are changed or eliminated 
by storage, and of those produced as secondary bodies during aging; 
and, in addition thereto, the substances extracted from the casks in 
which it has been stored. It contains, when prepared for consumption, 
as permitted by the regulations of the Bureau of Internal Revenue, not 
less than 45% by volume of ethyl alcohol, and, if no statement is made 
concerning its alcoholic strength, it contains not less than 50% by 
volume of ethyl alcohol as prescribed by law. 

Cognac, Cognac Brandy, is brandy produced in the departments of 
the Charente and Charente Inferieure, France, from wine produced in 
those departments. 

U. S. Pharmacopoeia Standards.— According to the U. S. Pharmacopoeia, 
brandy should be at least four years old; its specific gravity should be 



ALCOHOLIC BEVERAGES. 741 

not more than 0.941 nor less than 0.925; its alcohohc content should 
be from 39 to 47 per cent by weight; the residue from 100 cc. should 
not exceed 0.5 gram, and should dissolve readily in 10 cc. of cold water, 
and this solution should not be colored deeper than a pale green by the 
addition of dilute ferric chloride solution (absence of more than traces 
of tannin); the residue should not be sweet nor spicy in taste; a marked 
disagreeable pungent odor of fusel oil should not manifest itself on the 
volatilization of the last traces of alcohol in evaporating for the residue; 
in acidity, not more than i cc. of tenth-normal alkali should be required 
to neutralize 100 cc. of the brandy, using litmus as an indicator. 

Adulteration of Brandy. — Much of the brandy sold on the market 
is a compound or imitation, having for its basis alcohol reduced to the 
requisite strength, flavored either by the admixture of real brandy, or by 
various preparations such, for example, as syrup of raisins, prune juice, 
rum, acetic ether, oenanthic ether, infusion of green walnut-hulls, infusion 
of bitter almond shells, catechu, balsam of Tolu, etc. 

Fleischmann gives the following recipe for artificial brandy of the 
cheapest grade: 

Spirits 45 gallons 

Coloring (caramel) 6 ounces 

Cognac oil i ounce 

" Cognac oil " is made up of melted cocoanut oil 16 ounces, sulphuric 
acid 8 ounces, alcohol 16 ounces, mixed and distilled. 

While commercial brandy often fails to meet the pharmacopoeial 
requirements, and may contain any of the above flavoring materials, 
not one sample has been found among the many examined by the Massa- 
chusetts Board of Health during upwards of twenty years containing a 
more injurious ingredient than alcohol. 

Genuine new brandy may be "aged" or "improved" for immediate 
use, according to Duplais, by adding to 100 liters the following: 

Old rum 2 . 00 liters 

Old kirsch* 1.75 " 

Infusion of walnut -hulls 75 liter 

Syrup of raisins 2 .00 liters 

The addition of sugar and caramel to brandy is very common. The 



* Brandy distilled from cherry wine. 



742 FOOD INSPECTION yIND ^N^ LYSIS. 

lack of flavor resulting from the employment of "silent spirit," or from 
watering the product, may be compensated for by the employment of 
so-called cognac essences sold for the purpose, containing mixtures of 
the aromatic compounds named above. 

RUM. 

Rum is the liquor distilled from fermented molasses or cane juice, 
or from the scum and other waste juices from the manufacture of raw 
sugar. The molasses wort is mixed with the residue from a previous 
fermentation and allowed to ferment for a number of days, after which 
it is distilled twice and stored in wood for a long time, to remove the dis- 
agreeable odor, which in the new product is especially marked. The 
characteristic flavor of old rum is due to a mixture of butyric and acetic 
ether, principally the former. Pineapples and guavas are often put 
in the stiil to impart a fruity flavor. The best varieties of rum come 
from Jamaica and Vera Cruz. 

Composition. — The following analysis of rum is by Vasey: * 

Volatile acids 28.0 grams per 100 liters 

Esters 399.0 " " 

Aldehydes 8.4 

Furfural 2,8 " " 

Fusel oil 90.6 " " 

Thirty-nine samples of rum, sold at retail in Massachusetts in 1894, 
were examined by the State Board of Health with the following results: 





Per Cent 

Alcohol by 

Weight. 


Per Cent 
Extract. 


Maximum 


42.9 
24.7 
37-1 


3-93 
0.04 
0.51 


Minimum 


Mean 





Of these, two samples were new rum, and several were entirely arti- 
ficial. 

Joint Standards. — The following are the joint standards of the 

A. O. A. C. and the A. S. N. F. D. D. : 



* Analysis of Potable Spirits, p. 85. 



ALCOHOLIC BEVERAGES. 743 

New Rum is properly distilled spirit made from the properly fer- 
mented clean, sound juice of the sugar cane, the clean, sound massacuite 
made therefrom, clean, sound molasses from the massecuite, or any sound 
clean intermediate product save sugar, and contains in 100 liters of 
proof spirit not liss than 100 grams of the volatile flavors, oils, and 
other substances derived from the materials of which it is made, and 
of the substances congeneric with the ethyl alcohol produced during 
fermentation, which are carried over at the ordinary temperatures of 
distillation, the principal part of which is higher alcohols estimated as 
amylic. 

Rum {Potable Rtim) is new rum stored not less than four years in 
wood without any artificial heat save that which may be imparted by 
warming the storehouse to the usual temperature, and contains in 100 
liters of proof spirit not less than 175 grams of the substances found in 
new rum, save as they are changed or eliminated by storage, and of those 
produced as secondary bodies, during agings and, in addition thereto, 
the substances extracted from the casks. It contains, when prepared 
for consumption as permitted by the regulations of the Bureau of Inter- 
nal Revenue, not less than 45% by volume of ethyl alcohol, and if no 
statement is made concerning its alcoholic strength, it contains not less 
than 50% by volume of ethyl alcohol as prescribed by law. 

More or less factitious rum is sold on the market, made up of alcohol 
diluted to the right strength, colored with caramel, and flavored by the 
addition of " rum essence." Prune juice is sometimes added. 

Fleischman gives the following recipe for low-grade artificial rum: 

Spirits 40 gallons 

New England rum 5 " 

Prune juice h gallon 

Caramel 12 ounces 

Rum essence 8 " 

The "rum essence" is made up by distilling 32 ounces of a mixture 
of 2 ounces black oxide of manganese, 4 ounces pyroligneous acid, 32 
ounces alcohol, and 4 ounces sulphuric acid. To this is added 32 ounces 
of acetic ether, 8 ounces of butyric ether, 16 ounces saffron extract, and 
^ ounce oil of birch. 



744 tOOD INSPECTION AND ANALYSIS. 



GIN. 



Gin is an alcoholic liquor, flavored with the volatile oil of juniper and 
sometimes with other aromatic substances, such as coriander, grains of 
paradise, anise, cardamom, orange-peel, and fennel. The choicest variety 
is known as Schiedam schnapps, named from the town of Schiedam in 
Holland, where there are upwards of 200 distilleries devoted to the manu- 
facture of gin. The mash used for this variety is fermented by yeast 
from malted barley and rye, after which it is distilled and redistilled 
in pot stills with juniper berries and sometimes hops. 

Juniper berries, to which the most characteristic flavor of gin is due, 
are dark blue in color, and possess a pungent taste. They grow on the 
slender evergreen shrub Juniperus communis. Gin differs from the 
other distilled liquors by being water-white. To this end it is kept in 
glass and not in wood. 

Much of the gin of commerce is made by redistilling com or grain 
whiskey with oil of juniper, and frequently one or several of the above- 
named flavoring materials. Sugar is often added, and sometimes in the 
cheaper productions oil of turpentine is substituted for juniper oil. 

Composition. — Tiie following analysis of unsweetened gin is by Vasey: * 

Volatile acids o.o grams per 100 liters 

Esters 37.3 

Aldehydes 1.8 

Furfural 0.0 " " 

Fusel oil 44-6 

Thirty-three samples of gin, purchased in Massachusetts saloons and 
analyzed by the State Board of Health in 1894, gave the following 
results in per cent of alcohol by weight: Maximum 42.5, minimum 29.5, 
mean 38.2. 

* Analysis of Potable Spirits, p. 85. 



ALCOHOLIC BEVERAGES. 745 

METHODS OF ANALYSIS OF DISTILLED LIQUORS. 

Specific gravity and alcohol are determined as described on pp. 657- 
677. The following methods with the exception of the qualitative test 
for fusel oil, Mitchell's method, and McGill's opalescence test are 
those of the A. O. A. C * 

Determination of Extract. — Weigh or measure (at 15.6° C.) 100 cc. 
of the sample, evaporate nearly to dryness on the water-bath, then 
transfer to a water-oven, and dry at the temperature of boiling water 
for 2h hours. 

Determination of Acids. — Titrate 100 cc. (or 50 cc. diluted to 100 cc. 
if the sample is dark in color) with tenth-normal alkah, using phenol- 
phthalein as indicator, i cc. of tenth-normal alkali is equal to 0.006 of 
acetic acid. 

Determination of Esters. — Dilute 200 cc. of the sample with 25 cc. 
of water and distil slowly into a graduated 200-cc. flask until nearly 
filled to the mark. Complete the volume, shake, and use aliquot 
portions for the determination of esters, aldehydes, and furfural. 

Exactly neutrahze 50 cc. of the distillate with tenth-normal alkah, 
using phenolphthalein as indicator, and add from 25 to 50 cc. of the 
tenth-normal alkali in excess of that required for neutralization. Either 
boil for one hour with a reflux condenser, or allow to stand overnight 
in a stoppered flask, and heat with a tube condenser for one-half hour 
below the boiling-point. Cool, and titrate with tenth-normal acid, using 
phenolphthalein as indicator. Multiply the number of cc. of tenth- 
normal alkali used in the saponification by 0.0088, thus obtaining the 
grams of esters calculated as ethyl acetate. 

Determination of Aldehydes. — i. Reagents. — {a) Alcohol Free from 
Aldehydes. — Prepare by first redistilling the ordinary 95% alcohol over 
caustic soda or potash, then add from 2 to 3 grams per liter of m-phenyl- 
enediamine hydrochloride, digest at ordinary temperature for several 
days (or reflux on the steam-bath for several hours), and then distil 
slowly, rejecting the first 100 cc. and the last 200 cc. 

{h) Sulphite-fuchsin Solution. — Dissolve 0.50 gram of pure fuchsin 
in 500 cc. of water, then add 5 grams of SO2 dissolved in water, make 
up to a hter, and allow to stand until colorless. Prepare this solution 
in small quantities, as it retains its strength for only a very few days. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), pp. 95 to lor; Circular 43. 



746 FOOD INSPECTION /IND AN yl LYSIS. 

(f) Standard Acetic Aldehyde Solution. — Prepare according to the 
directions of Vasey * as follows : Grind aldehyde ammonia in a mortar 
with ether, and decant the ether. Repeat this operation several times, 
then dry the purified salt in a current of air and finally in a vacuum 
over sulphuric acid. Dissolve 1.386 grams of this purified ammonium 
aldehyde in 50 cc. of 95% alcohol, to this add 22.7 cc. of normal alco- 
holic sulphuric acid, then make up to 100 cc. and add 0.8 cc, to com- 
pensate for the volume of the ammonium sulphate precipitate. Allow 
this to stand over night and filter. This solution contains i gram of 
acetic aldehyde in 100 cc. and will retain its strength. 

The standard found most convenient for use is 2 cc. of this strong 
aldehyde solution diluted to 100 cc. with 50% alcohol by volume. One 
cc. of this solution is equal to 0.0002 gram of acetic aldehyde. This solu- 
tion should be made up fresh every day or so, as it loses its strength. 

2. Process. — Determine the aldehyde in the distillate prepared for 
esters. Dilute from 5 to 10 cc. of the distillate to 50 cc. with aldehyde- 
free alcohol (50% by volume), add 25 cc. of the fuchsin solution, and 
allow to stand for fifteen minutes at 15° C. The solutions and the 
reagents should be at 15° C. before they are mixed. Prepare standards 
of known strength in the same way. 

Determination of Furfural. — Standard Furfural Solution. — Dissolve 
I gram of redistilled furfural in loc cc. of 95% alcohol. This strong 
solution will keep. Standards are made by diluting i cc. of this solution 
to 100 cc. with 50% by volume alcohol. One cc. of this solution con- 
tains o.oooi gram furfural. 

Process. — Dilute from 10 to 20 cc. of the distillate, prepared as 
described under esters, to 50 cc. with furfural-free alcohol (50% by 
volume). To this add 2 cc. of colorless anilin and 0.5 cc. of hydro- 
chloric acid (specific gravity 1.125), and keep for fifteen minutes in a 
water-bath at about 15° C. Prepare standards of known strength in 
the same way. 

Detection of Fusel Oil. — In the process of dealcoholizing a liquor by 
evaporation in an open dish over the water-bath, one may readily detect 
fusel oil, if present, by its harsh and nauseating odor, if the nose is 
applied just at the moment when the last traces of alcohol are going 
off. At this stage any considerable trace of fusel oil will be especially 
apparent by the effect on the throat of the one who smells it, causing 

* Analysis of Potable Spirits, p. 30. 



ALCOHOLIC BEVERAGES. 747 

an uncontrollable desire to cough. Other ways of applying the odor 
test consist in pouring a small portion of the spirit into the hand, and 
allowing it to evaporate slowly therefrom, or in rinsing out a warm glass 
with the Hquor, observing the odor in each case. 

Goebel suggests the following test, based on the detection of the 
volatile acids: Agitate about 30 cc. of the liquor with 2 or 3 cc. of 
a dilute solution of potassium hydroxide; evaporate over the water- 
bath to the volume of 2 or 3 cc, cool, and to the residue add 5 or 6 cc. 
of concentrated sulphuric acid. If fusel oil be present, the character- 
istic odors of valerianic and butyric acids will be apparent. 

Determination of Fusel Oil. — Allen-Mar quardt Method. — Add to 
100 cc. of whiskey 20 cc. of half-normal sodium hydroxide, and saponify 
the mixture by boiling for one hour under a reflux condenser.* Connect 
the flasks with a distilling apparatus, distil 90 cc, add 25 cc. of water, 
and continue the distillation until an additional 25 cc. is collected. 

Approximately saturate the distillate with finely ground sodium 
chloride, and add a saturated solution of sodium chloride until the specific 
gravity is i.io. 

Extract this salt solution four times with carbon tetrachloride,! using 
40, 30, 20, and ID cc. respectively, and wash the carbon tetrachloride 
three times with 50-cc. portions of a saturated solution of sodium chloride, 
and twice with saturated solution of sodium sulphate. Then transfer 
the carbon tetrachloride to a flask containing 5 cc of concentrated 
sulphuric acid, 45 cc. of water, and 5 grams of potassium bichromate, 
and boil for eight hours under a reflux condenser. 

Add 30 cc of water, and distil until only about 20 cc. remain; add 
80 cc of water, and distil until but 5 cc. are left. Neutrahze the distillate 
to methyl orange, and titrate with sodium hydroxide, using phenol- 
phthalein as indicator. One cc. of tenth-normal sodium hydroxide is 
equivalent to 0.0088 gram of amyl alcohol. 

Rubber stoppers can be used in the saponification and first distilla- 
tion, but corks covered with tinfoil must be used in the oxidation and 
second distillation. Corks and tinfoil must be renewed frequently. 



* Or 100 cc. of the liquor may be mixed with 20 cc. of half-normal sodium hydroxide, 
allowed to stand overnight at room temperature, and distilled directly. 

t Purify 5 liters of carbon tetrachloride by boiling for several hours under a reflux con- 
denser with 200 cc. of sulphuric acid and 25 grams of potassium bichromate in 200 cc. of 
water; separate from the oxidizing mixture by distillation, and redistil over barium car- 
bonate. 



74^ FOOD INSPECTION AND ANALYSIS. 

Tolman and Hillyer's Modification of the Allen- Marqiiardt Method. — 
Proceed with the Allen-Marquardt method to the point where the 
carbon tetrachloride solution of the higher alcohols is ready to be 
oxidized. Add 50 cc. of a solution of 200 grams of pulverized potassium 
bichromate in 1800 cc. of water and 200 cc. of concentrated sulphuric 
acid, very carefully .measured with pipette or burette, and start the 
eight-hour oxidation. Take great care to prevent any isolation of spots 
of bichromate on the flask during the oxidation. Decomposition of 
the bichromate from overheating can best be prevented by slow boiling 
over several thicknesses of asbestos board. After the oxidation is 
complete, separate the bichromate solution from the carbon tetrachloride 
in a separatory funnel, care being taken to wash the carbon tetrachloride 
free from bichromate. Make up the bichromate solution to 500 cc. 
Place 200 cc. of this solution in a liter flask, add 20 cc. of concentrated 
hydrochloric acid, 100 cc. of potassium iodide solution (1:1), and 50 cc. 
of approximately three-fourths normal thiosulphate not standardized. 
Make this last addition by means of a burette. (If a high content of 
fusel oil is present, 50 cc. of thiosulphate may be excessive and a smaller 
amount should be used, the same quantity being added to the sample 
and to the blank.) Run blanks containing exactly the same amount 
of reagents with each series, and treat them in the same way, starting 
them at the point where the carbon tetrachloride is washed with sodium 
chloride. The titration of this blank, to which has been added exactly 
the same amount of three-fourths normal thiosulphate, gives the value 
of the bichromate solution. The difl"erence in cubic centimeters of tenth- 
normal thiosulphate used in titrating the blank and the samples gives 
the amount of bichromate reduced by the higher alcohols. This differ- 
ence in cubic centimeters of tenth-normal thiosulphate multiplied by 
the factor 0.001773 gives grams of higher alcohols present. 

Mitchell's Method.''^ — This method is more rapid than the Allen- 
Marquardt method and gives more nearly the true amount of fusel oil. 

Saponify, distil, shake with sodium chloride, and extract with carbon 
tetrachloride, as in the Allen-Marquardt method. To the carbon tetra- 
chloride extract, contained in the separatory funnel, add 10 cc. of 
potassium hydroxide solution (1:1). Cool the mixture in ice-water to 
approximately 0° C. Similarly cool 100 cc. of a solution of potassium 
permanganate solution (20 grams to the liter), accurately measured in 

*A. O. A. C. Proc, 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 199. 



ALCOHOLIC BEVERAGES. 749 

a flask. To the contents of the separatory funnel add the bulk of the 
permanganate solution, but without rinsing, retaining the residue to be 
added at a later stage. Remove the mixture from the bath, and shake 
vigorously for five minutes; set aside for thirty minutes, with occasional 
shaking, permitting the hquid to warm to room temperature (20 to 25° C.) 

Accurately measure into a liter Erlenmeyer flask 100 cc. of a solution 
of hydrogen peroxide slightly (about 2%) stronger than the perman- 
ganate solution, acidulate with 100 cc. of an approximately 25% sul- 
phuric acid solution, and slowly add the contents of the separatory 
funnel with constant shaking, keeping the acid solution constantly in 
excess. Rinse the separatory funnel and the flask containing the residue 
of permanganate with water and add to the peroxide solution. Finally 
titrate the excess of hydrogen peroxide with standard potassium per- 
manganate solution (10 grams to the liter). 

Run a blank determination, using the same amounts of the stronger 
permanganate, potassium hydroxide, hydrogen peroxide, and sulphuric 
acid solutions, and titrating the residual peroxide with the standard 
potassium permanganate as before. 

The difference in the amounts of permanganate consumed, in grams, 
times 0.696, gives the amount of amyl alcohol. 

Detection of Methyl Alcohol. — Leach and Lyihgoe Immersion Refrac- 
tometer MeiJiod.^ — Determine at 20° C. the refraction of the distillate 
obtained in the determination of alcohol by the immersion refractometer. 
If on reference to the table the refraction shows the percentage of alcohol 
agreeing with that obtained from the specific gravity, it may be safely 
assumed that no methyl alcohol is present. If, however, there is an 
appreciable amount of methyl alcohol, the low refractometer reading will 
at once indicate the fact. If the absence from the solution of other 
refractive substances than water and the alcohols is assured, this quali- 
tative test by difference in refraction is conclusive. 

The addition of methyl to ethyl alcohol decreases the refraction in 
direct proportion to the amount present; hence the quantitative calcu- 
lation is readily made by interpolation in the table, using the figures 
for pure ethyl and methyl alcohol of the same alcoholic strength as the 
sample. 

Example. — Suppose the distillate made up to the original volume 
of the measured portion taken for the alcohol determination has a 

* Jour. Am. Chem. Soc, 27, 1905, p. 964. 



750 



FOOD INSPECTION AND /iN A LYSIS. 



specific gravity of 0.9736, corresponding to 18.38% alcohol by weight, 
and has a refraction of 35.8 at 20° C. by the immersion refractometer; 
by interpolation in the refractometer table the readings of ethyl and 
methyl alcohol corresponding to 18.38% alcohol are 47.2 and 25.4, 
respectively, the difference being 21.8; 47.2—35.8=11.4; (11.44-21.8) 
100=52.3, showing that 52.3 of the alcohol present is methyl alcohol. 



SCALE READINGS ON ZEISS IMMERSION REFRACTOMETER AT 20° C, 
CORRESPONDING TO EACH PER CENT BY WEIGHT OF METHYL AND 
ETHYL ALCOHOLS. 





Scale 




Scale 




Scale 




Scale 




Readines. 




Readings. 




Read 


ings. 




Readings. 


Per Cent 






Per Cent 
Alcohol 






Per Cent 
Alcohol 






Per Cent 
Alcohol 






Alcohol 


















by 
Weight. 


Methyl 
Al- 


Ethyl 
Al- 


by 
Weight. 


Methyl 
Al- 


Ethyl 
Al- 


by 
Weight. 


Methyl 
Al- 


Ethyl 
Al- 


by 
Weight. 


Methyl 
Al- 


Ethyl 
Al- 




cohol. 


cohol. 




cohol. 


cohol. 




cohol. 


cohol. 




cohol 


cohol. 





14-S 


14-S 


26 


30-3 


61.9 


51 


39-7 


91. 1 


76 


29.0 


lOI.O 


I 


14.8 


16.0 


27 


30-9 


63-7 


52 


39-6 


91.8 


77 


28.3 


100.9 


2 


15-4 


17.6 


28 


31.6 


65-5 


53 


39-6 


92-4 


78 


27.6 


100.9 


3 


16.0 


19. 1 


29 


32.2 


67.2 


54 


39-5 


93-0 


79 


26.8 


100.8 


4 


16.6 


20.7 


30 


32.8 


69.0 


55 


39-4 


93-6 


80 


26.0 


100.7 


5 


17.2 


22.3 


31 


33-5 


70.4 


56 


39-2 


94-1 


81 


25-1 


100.6 


6 


17.8 


24.1 


32 


34-1 


71.7 


57 


39-0 


94-7 


82 


24-3 


100.5 


7 


18.4 


25-9 


Zi 


34-7 


73-1 


58 


38.6 


95-2 


83 


23.6 


100.4 


8 


19.0 


27.8 


34 


35-2 


74-4 


59 


38.3 


95-7 


84 


22.8 


100.3 


9 


19.6 


29.6 


35 


35-8 


75-8 


60 


37-9 


96.2 


85 


21.8 


100. 1 


10 


20.2 


31-4 


36 


36.3 


76.9 


61 


37-5 


96-7 


86 


20.8 


99.8 


II 


20.8 


33-2 


37 


36.8 


78.0 


62 


37-0 


97.1 


87 


19.7 


99-5 


12 


21.4 


35-0 


38 


37-3 


79-1 


63 


36.5 


97-5 


88 


18.6 


99.2 


13 


22.0 


36-9 


39 


37-7 


80.2 


64 


36.0 


98.0 


89 


17-3 


98.9 


14 


22.6 


38.7 


40 


38.1 


81.3 


65 


35-5 


98-3 


90 


16. 1 


98.6 


15 


23.2 


40-5 


41 


38-4 


82.3 


66 


35-0 


98-7 


91 


14.9 


98-3 


16 


23-9 


42.5 


42 


38-8 


83-3 


67 


34.5 


99-1 


92 


13-7 


97.8 


17 


24-5 


44-5 


43 


39-2 


84.2 


68 


34-0 


99-4 


93 


12.4 


97-2 


18 


25-2 


46.5 


44 


39-3 


85-2 


69 


33-5 


99-7 


94 


II. 


96.4 


19 


25.8 


48.5 


45 


39-4 


86.2 


70 


33-0 


100. 


95 


9.6 


95-7 


20 


26.5 


50-5 


46 


39-5 


87.0 


71 


32-3 


100.2 


96 


8.2 


94.9 


21 


27.1 


52-4 


47 


39-6 


87.8 


72 


31-7 


100.4 


97 


6.7 


94.0 


22 


27.8 


54-3 


48 


39-7 


88.7 


73 


31-1 


100.6 


98 


5-1 


93 -o 


23 


28.4 


56.3 


49 


39-8 


89-5 


74 


30-4 


100.8 


99 


3-5 


92.0 


24 


29.1 


58.2 


50 


39-8 


90-3 


75 


29.7 


lOI.O 


100 


2.0 


91.0 


25 


29-7 


60.1 





















Trillat Method."^ — To 50 cc. add 50 cc. of water and 8 grams of lime, 
and fractionally distil by the aid of Glinksy bulb tubes. Dilute the 



*A. Trillat, Analyst, 24, 1899, PP- ^3) 211-212. 



ALCOHOLIC BEyERAGES. 751 

first 15 cc. of the distillate to 150 cc, mix with 15 grams of potassium 
bichromate and 70 cc. of sulphuric acid (1:5), and allow to stand for 
one hour with occasional shaking. 

Distil, reject the first 25 cc, and collect 100 cc. Mix 50 cc. of the 
distillate with i cc of rectified dimethyl-anilin, transfer to a stout, 
tightly-stoppered flask, and keep on bath at 70 to 80° C. for three hours 
with occasional shaking. Make distinctly alkahne with sodium hydrox- 
ide, and distil the excess of dimethyl-anilin, stopping the distillation 
when 25 cc. have passed over. 

Acidify the residue in the flask with acetic acid, shake, and test a 
few cc. by adding four or five drops of water with lead dioxide in 
suspension (i gram in 100 cc). If methyl alcohol be present, a blue 
coloration occurs which is increased by boiling. 

Note. — Ethyl alcohol thus treated yields a blue coloration, changing 
immediately to green, afterwards to yellow, and becoming colorless when 
boiled. 

Riche and Bardy MethoaJ^ — The following method for the detection 
of methyl alcohol in commercial spirit of wine depends on the formation 
of methyl-anihn violet: 

Place 10 cc. of the sample, previously rectified over potassium car- 
bonate if necessary, in a small flask with 15 grams of iodine and 2 grams 
of red phosphorus. Keep in ice-water for from ten to fifteen minutes 
until action has ceased. Distil on a water-bath the methyl and ethyl iodides 
formed into about 30 cc. of water. Wash with dilute alkali to eliminate 
free iodine. Separate the heavy oily liquid which settles, and transfer 
to a flask containing 5 cc. of anilin. The flask should be placed in cold 
water, in case the action should be violent, or, if necessary, the reaction 
may be stimulated by gently warming the flask. After one hour boil 
the product with water, and add about 20 cc. of a 15% solution of soda; 
when the bases rise to the top as an oily layer, fill the flask up to the 
neck with water, and draw them off with a pipette. Oxidize i cc. of 
the oily hquid by adding 10 grams of a mixture of 100 parts of clean 
sand, 2 of common salt, and 3 of cupric nitrate; mix thoroughly, intro- 
duce into a glass tube, and heat to 90° C. for eight or ten hours. Exhaust 
the product with warm alcohol, filter, and make up with alcohol to 100 cc. 
If the sample of spirits be pure, the liquid is of a red tint, but in the 
presence of 1% of methyl alcohol, it has a distinct violet shade; with 

* Allen's Commercial Organic Analysis, 3d ed., I, p. 80, 



75* 



/•(»(>/> INSriCI ION .INI) .IN.II.YSIS. 




2.5'/^, llic sIi.'kIc is very "li'lim I, ;iii(l .'.lill nunc so with 5%. To (k-U:ct 
more iiiiiiiilr (ni.iiililits ol iiiclhyl iiIcoIk.I, dilnic c; cc. of the colored 
I i( I II ill lo KM) ( ( . will) \v;ilti, .111(1 dill lie 1, ( ( . ol lliis ;i)'aiii lo .joo ( c. I lc;ii 
the li(|iii<l lliiis ohiaiiK'd in | iok tl.iiii, .iinl iiiiiiiciM' .1 h .'ijmiiciiI ol wliili; 
merino (I'rcc from siil|tliiii) in il loi li.ill .111 lioni. II llic .iliolio! he 
iiiiic. llic wool will icniiiin w lull , Kill it mil li\ lalci I , llic lilici will l)c(omo 
violcl, llic 11(1)111 ol Iinl )M\'iii}', .1 lair .'ipproximalc iii- 
^\ (liialioii III llic {)io|ioilioii ol mcllivl alioliol pn-sciil. 

Dcteclion ol (.'ninmcl. ( 'iiiiii /'/on niid Siiiioii's 
Milliiiil:^ l'',\a|)oialc S'J • • • '*' l'"' li<|'ioi iicailvhiil not 
ijiiilc lo ill \ lie ss in an cvapoi al inj', ilisli on llic vvalci bail). 
Wash Willi wall! iiilo a S"<<- J^r.'iilualcil j^lass sloppcrcd 
Mask, aild 25 CC. ol ahsolnlc alioliol, and lill lo llic mark 
vvilli walcr. Shake, and liaii;,lci .'S 11. ol llie solulioii 
lo a sepaialoi\' limncl ol llic l\pe picMiiled in |''i|^. 1 if», 
th<' sicni ol wliiili ierminalcs in a .•c;(i. I'jadiialed 
hull) pipellc, piovidcd Willi a slop eoi k as shown. 

Add 'v ' ' ' • <'l ilhei, and shake i aiel'ully al ililervals 
dniiiir, hall an hoiii. Allei' loiiiplele se|)arat ion, make 

ll|) Ihe lower aipleoiis la\el willi walel lo llic .'c;''*"- 
mail , wliiili iiia\' he done l)\' siphoniiir, il 111 Ihroiij^li 
a MiMici liihe lioiii an clevalcd Mask, loiiliolliii)' ihc 
siipph li\ llie '.lopioik. Shake llic sepaialo!\ liiiiiici, 
and ajsiiii allow ihe la\eis lo Ncpaialc, draw oil ihe 
•'"• II'' ''i|Mi:i- ai|iieoiis la\ir, and eompaie willi llie color ol llie ori|j;- 

l< M \ I' llllllc'l ji II ' II' I ' ,1 , I I I 

inal iiijiioi. r,\|)i'ess Ihe anioiiiil oj 1 oloi rciiioxed as 

n.ir .,1 ' ' 

(•,1,111,. I per I eiil III Ihe lolal aiiioiiiil. I'',lliel will leadiU dis- 

solve llie naliiial 1 oloi due lo oakwood (maiiih Have-' 
scin), while earaniel is insohiMe in elhei; lieiiee iiiieoloied liipiors are 
partialis' dei oloi i/.ed |)\' llii.s liealiiieiil, while I hose i oloieil willi laiaillel 
show III lie change. 

Aiir.lior Test, Modijiiil hy l.<i\ilic.\ Add 10 ec. ol' paraldelnde (o 
t; ce. ol ihe sample tonlained in a lesl lulu- and shake. Add ahsolule 
alcohol, a lew drops al a lime, .'.liakiii)'; allei each addilion iiiilil llie 
mixture becomes clear. .\llow lo sland. 'riiihidilN allei leu miiiiiles 
is jin indiculion ot caramel. 



* jnlii. Am ('hem. Sot., jj 11)011, p. HlO. 
I I'lii- Hhw.i l)i;,|illri, M.iv. n;>>{. 



ALCOHOLIC HRyERAGHS. 753 

Determination of Water-insoluble Color in Whiskies. — Evaporate 
50 cc. of till- sample just to dryness. Take u]) wilh eold water, using 
apj)roximalcly 15 cc, filter, and wash until the lillrate amounts to nearly 
25 cc. To this liltrale add 25 cc. of absolute alcohol or 26.3 cc. of 95% 
by volume alcohol, and make up lo 50 cc. by the addition of water. 
Mi.\ thoroufi;hly and compare in a colorimeter with the original material. 
Calculate I he pir cent of color insoluble in water from these reath'ngs. 

Determination of Color Insoluble in Amyl PdcohoX.^ Modified Marsh 
7V.S7. -Evaporate 50 cc. of the whiskey just lo dryness on the .steam- 
bath. Add 26.3 cc. of 95% aicoiiol tg dissolve the residue. Tran.sfer 
to a 50-cc. llask and make uj) to volume with water to obtain a uniform 
alcohol concentration. Place 25 cc. of this solution in a .se[)aratory 
funnel, and add 20 cc. of the Marsli reagent, shaking lightly so as not 
to form an emulsion. (This reagent consists of too cc. of pure amyl 
alcohol, 3 cc. of syrupy phosphoric acid, and 3 cc. of water; shake 
before using.) Allow the layers to separate, and repeat this shaking 
and standing twice again. After the layers have clearly separated, draw 
off the lower or watery layer which contains the caramel into a 25-cc. 
cylinder, and make uj) lo volume with 50% by volume alcohol. Com- 
pare this solution in a colorimeter wilh the untreated 25 cc. Calculate 
the result of this reathng to the |)er cent of color insoluble in amyl 
alcohol. 

Opalescence in Diluted Alcohol Distillate. — McGill * has shown that 
in the case of h(|uors made from thoroughly rectified grain si)iril, there 
is little or no opalescence pnxhued when the alcoholic distillate (i.e., 
that used in determining ihe alcohol) is diluted with an e(pial volume 
of water, while in the case of lifjuors distilled from alcoholic infusions 
without reel ifu at ion, the o|)ali'scence is marked. He ascribes the o])ales- 
cence to the ]jre.sence of minute amounts of volatile oils present in wine 
maic, grains, and other sources of these liquors, soluble in strong, but 
insoluble in dilute alcohol. Whether due lo this or U) ihe separation 
of minute traces of fusel oil on dilution, the presence or absence of tur- 
bidity certainly furnishes a rough distinguishing lest, indicating in some 
cases the exclusive use of rectified spirit. 



* liul. 27, C';in;i(|i;m Inland Rev. Dept. 



754 FOOD INSFECTiON yiND ANALYSIS. 

LIQUEURS AND CORDIALS. 

These are manufactured beverages, usually high in alcohol and sugar, 
flavored with a wide variety of aromatic herbs or essences, and often 
strongly colored. Red colors most frequently used for this purpose 
are cochineal, cudbear, and red sandal and Brazil woods; for yellow 
colors, caramel and saffron-yellow are employed; for blue, indigo; and 
for green, chlorophyll and malachite green. 

Some of the oldest of the liqueurs, such as chartreuse and benedictine, 
derive their names from certain monasteries of Europe, in which they 
have been made for many years. 

Absinthe is one of the best-known cordials, made by redistilling 40% 
alcohol in which wormwood, anise, sweet flag, and marjoram leaves 
have been macerated. Sometimes coriander and fennel are also used. 
It is highly intoxicating, 

Cura^oa is made by distilling dilute spirits in which Curafoa orange- 
peel,* cinnamon and often other spices have been soaked, and by adding 
sugar to the resulting liqueur. 

De Brevans gives the following recipe for curagoa: 

Rasped skins of. . 18 or 20 oranges 

Cinnamon 4 grams 

Mace 2 " 

Alcohol (85%) 5 liters 

White sugar 1750 grams 

Macerate for fourteen days, distill without rectification, and color with 
caramel. 

Angostura owes its flavor to Angostura bark and various spices. 

Maraschino had originally for its basis the fermented juice of the 
sour Italian cherry, to which honey was added. It is more commonly 
made by distilling a mixture in alcohol of ripe wild cherries, raspberries, 
cherry leaves, peach nuts, and orris. Finally sugar is added. 

Chartreuse and Benedictine contain much sugar, and are flavored 
with the volatile oils of angelica, hyssop, nutmeg, and peppermint. 

Noyau, or Creme de Noyau, is a preparation distilled from brandy, 
bitter almonds, mace and nutmeg. Sugar and coloring matter, usually 
pink, arc added to the final product. 

* This is a very rare and highly prized orange, growing in the island of Curaf oa. 



ALCOHOLIC BEVERAGES. 755 

Creme de Menthe, according to De Brevans, is made by distilling a 
mLxture of 

Peppermint 600 grams 

Balm 40 " 

Sage 10 " 

Cinnamon 20 " 

Orris root 10 " 

Ginger 15 " 

Alcohol (80%) 5030 cc. 

producing finally 10 liters of the liquor, after 3750 grams of white sugar 
have been introduced. 

The better grades of creme de menthe were formerly colored with 
an alcoholic solution of chlorophyll, derived by macerating bruised green 
leaves of various plants with alcohol, but at present, coal-tar dyes are 
used. Frequently the desired shade is secured by mixing a green (e.g., 
Light Green S.F.), a blue-green (e.g.. Malachite Green), or a blue (e.g., 
Indigo Carmine) with a yellow color. 

The following analyses, due to Konig, show the chemical composition 
of the best-known cordials: 



specific 
Gravity. 



Alcohol 
by Vol- 

UTTle. 



Alcohol 

by 
Weight. 



Extract. 



Cane 

Sugar. 



Other 
Extrac- 
tives. 



Ash. 



Absinthe 

Benedictine 

Ginger 

Creme de menthe. . . . 
Anisette de Bordeaux 

Curagoa 

Kiimmel 

Angostura 

Chartreuse 



0.9116 
1.0709 
I. 048 I 
1.0447 
1.0847 
I . 0300 
1.0830 
0.9540 
1.0799 



58.93 

52 

47-5 
48.0 
42.0 
55-0 
33-9 
49-7 
43-18 



0.18 
36.00 

27-79 
28.28 
34-82 
28.60 
32.02 

5-85 
36.11 



0.32 

3-43 
1.87 
0.65 



0.84 
1 .69 
1.76 



-043 
.141 
.068 
.040 
.040 
.058 



Analysis of Cordials and Liqueurs. — The character of the essences 
and flavoring principles used in these beverages is so widely varied that 
no regular systematic plan for identifying them can be made applicable 
to all cases. The senses of smell and taste are most useful, both when 
applied directly to the liqueur itself and to the dry extract, for suggestions 
as to the main ingredients employed. Coloring-matters, sugars, acids, 
and alcohol are determined as with other liquors, except that in the case 
of alcohol all volatile oils must first be separated out by treatment with 
magnesia, as directed for alcohol in lemon extract. Presence of volatile 



756 FOOD INSPECTION /IND /IN A LYSIS. 

oils is shown, if on treatment of a few cubic centimeters of the sample 
in a test-tube with water a precipitate is formed. 

GENERAL REFERENCES ON ALCOHOLIC BEVERAGES. 

(See also References on Leavening Materials, page 275.) 

Bersch, J. Gahrungs-Chemie fur Praktiker. Berlin. Vol. I, Die Hefe und die Gahr- 

ungs Erscheinungen, 1879. Vol. II, Fabrikation von Malz, Malz Extract und 

Dextrin, 1880. Vol. Ill, Die Bierbrauerei, 1881. 
BiGELOW, W. D. Fermented and Distilled Liquors. U. S. Dept. of Agric, Bur. of 

Chem., Bui. 65, p. 81. 1902. 
BouRGUELOT, E. Des Fermentations. Paris, 1889. 

Brevans, J. DE. The Manufacture of Liquors and Preserves. New York, 1893. 
Crampton, C. a. Fermented Alcoholic Beverages. U. S. Dept. of Agric, Div. of 

Chem., Bui. 13, part 3. 1887. 
DuPLAis, P. (Translated by McKennie, M.) A Treatise on the Manufacture and 

Distillation of Alcoholic Liquors. Philadelphia. 
Fleischman, J. The Art of Blending and Compounding Liquors and Wines. New 

York, 1885. 
Girard, C. La Fabrication des Liqueurs et des Conserves. Paris, 1890. 
Hansen, E. Ch. Untersuchungen aus der Praxis der Gahrungs-Industrie. Miinchen, 

1889. 
Leach, A. E., and Lythgoe, H. C. The Detection and Determination of Ethyl and 

Methyl Alcohols in Mixtures by the Immersion Refractometer. Jour. Am. 

Chem. Soc, 27, 1905, p. 964. 
Mew, J., and Ashton, J. Drinks of the World. London, 1892. 
Pasteur, M. Studies in Fermentation. London, 1879. 

Prescott, a. B. Critical Examination of Alcoholic Liquors. New York, 1880. 
Spencer, E. The Flowing Bowl. A Treatise on Drinks of all Kinds and of all Periods. 

London, 1899. 
Stevenson, T. A Treatise on Alcohol with Tables of Spirit Gravities. London, 1888. 
■ A Treatise on the Manufacture, Imitation, Adulteration and Reduction of Foreign 

Wines, Brandies, Rums and Gins, based upon the " French System," by a 

Practical Chemist and Experienced Liquor Dealer. 

REFERENCES ON BEER. 

Allen, A. H., and Chattaway, W. Detection of Hop Substitutes in Beer. Analyst, 

12, 1887, p. 107; also Analyst 15, 1890, p. 181. 
Barnard, H. E. Report on Beer. U. S. Dept. of Agric, Bur. of Chem., Bui. 90, 

p. 64. 
Brevans, J. de. Analyse des Matieres Alimentaires (Girard et Dupre), p. 183. Paris, 

1894. . 
Elion, H. Detection of Antiseptics in Beer. Analyst, 16, 1891, p. 116. 
Faulkner, F. Theory and Practice of Modern Brewing. London, 1888. 
Hefelmann, R., and Mann, P. Detection of Fluorine in Beer. Pharm. Centralh., 

16, 1895, p. 249; Abs. Analyst, 20, 1895, p. 185. 



ALCOHOLIC BEl^ERAGES. 757 

Kelynack, T. N., and Kirby, W. Arsenical Poisoning in Beer Drinkers. London, 

1901. 
LiNDET, L. La Biere. Pans, 1892. 

LiNDNEE, C. Lehrbuch der Bierbrauerei. Braunsweig, 1878. 
Macfarlane, T. Malt Liquors. Canada Inl. Rev. Dept., Bui., 52. 
Paesons, C. L. The Identification and Composition of Malt Liquors. Jour. Am. 

Chem. See, 24, 1902, p. 11 70. 
Pasteur, M. Etudes sur la Biere. Paris, 1876. 
PiESSE, C. H. Chemistry in the Brewing Room. London, 1891. 
Prior, E. Chemie und Physiologie des Maizes und des Bieres. Leipzig, 1896. 
Stierlein, R. Das Biere und seine Verfalschungen. Berlin, 1878. 

REFERENCES ON CIDER AND WINE. 

Alwood, W. B. a Study of Cider Making. U. S. Dept. of Agric, Bur. of Chem., 

Bui. 71. 
Alwood, W. B., Davidson, R. J., and Moncure, W. A. P. The Chemical Com- 
position of Apples and Cider. U. S. Dept. of Agric, Bur. Chem., Bui. 88. 
Arauner, p. Der Wein und seine Chemie. Kitzingen, a. M., 1906. 
Barillot, E. Manuel de 1' Analyse des Vins. Paris, 1889. 
Barth, M. Die Weinanalyse. Leipzig, 1884. 
Bastide, E. Les Vins Sophistiques. Paris, 1889. 
Browne, C. A. The Chemical Analysis of the Apple, and some of Its Products. Jour. 

Am. Chem. Soc, 23, 1901, p. 869. 
The Effects of Fermentation upon the Composition of Cider and Vinegar. Jour. 

Am. Chem. Soc, 25, 1903, p. 16. 
BORGMANN, E. Anleitung zur chemischen Analyse des Weines. Wiesbaden, 1898. 
Cazeneuve, p. La Coloration des V-'ins par les Couleurs de la Houille. Paris, 1886. 
Chase, E. M. Qualitative Detection of Saccharine in Wine. Jour. Am. Chem. 

Soc, 26, 1904, p. 1627. 
Embrey, G. a Comparison of English and American Cider, v/ith Suggestions for 

Estimating the Amount of Added Water. Analyst, 16, 1891, p. 41. 
Gautier, a. La Sophistication des Vins. Paris, 1884. 
Macfarlane, T. Wines. Canada Inl. Rev. Dept., Bui. 38. 
Nessler, J. Die Bereitung, Pflege und Untersuchung des Weins. Stuttgart, 1889. 
NiviERE, G., and Hubert, A. Detection of Fluorine in Wine. Monit. Scient., 9, 

1895, p. 324; Abs. Analyst, 20, 1895, p. 185. 
Pasteur, M. Etudes sur le Vin. Paris, 1873. 
RoBiNET, E. Manuel Pratique d' Analyse des Vins. Paris, 1888. 
Sangle-Ferriere. Vin. Analyse des Matieres Alimentaires (Girard et Dupre), 

p. 65. Paris, 1894. 

Cidre. Loc cit., p. 217. 

Smith, A. W., and Parks, N. Composition of Ohio Wines. Jour. Am. Chem. Soc, 

20, 1908, p. 878. 
VlARD, E. Traite general des Vins et de leurs Falsifications. Paris, 1884. 
WiNDisCH, K. Die chemische Untersuchung und Beurtheilung des Weines. Berlin, 



7S8 FOOD INSPECTION AND ANALYSIS. 

REFERENCES ON DISTILLED LIQUORS. 

Allen, A. H. The Chemistry of Whiskey and Allied Products. Jour. Soc. Chem. Ind., 

lo, 1891, p. 312. 
Brannt, W. T. Practical Treatise on the Distillation of Alcohol. Phila., 1885. 
Crampton, C. a. Detection of Foreign Coloring Matter in Spirits. Jour. Am. Chem. 

Soc, 22, 1900, p. 810. 
Crampton, C. A., and Tolman, L. M. A Study of the Changes Taking Place in 

Whiskey Stored in Wood. Jour. Am. Chem. Soc, 30, 1908, p. 98. 
Gaber, a. Die Fabrikation von Rum, Arrak, Cognac, etc. Leipzig, 1886. 
Macfarlane, T., and McGill, A. Distilled Liquors. Canada Inl. Rev Dept., Bui. 

27. 
Mitchell, A. S. The Determination of Fusel Oil by Alkaline Permanganate. 

A. O. A. C. Proc 1908. U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 199. 
MouzERT. The Practical Distiller. 1890. 
Ladd, E. F. Whiskey. N. Dak. Agric. Exp. Sta. Bulletins 57, 63 and 69. Reports 

1906 and 1907. 
RiCHTER, H. Analyse des Rums. Zeits. landw. Gerwerbe, 9, 1889, p. 11. 
Sanglier, a. Alcohols et Spiritueux. Analyse des Matieres Alimentaires (Girard et 

Dupre), p. 253. Paris, 1894. 
ScALA, A. Rum and Its Adulteration. Gazetta Chem. Ital., 1891, 396; Abs» Ana- 
lyst, 17, 1892, p. 79. 
Sell, E. Ueber Cognac, Rum, Arrak, etc. Berlin, 1890. 
Shepard, J. H. The Constants of Whiskey. Report of the Chemist of the South 

Dakota Food and Dairy Commission, March, 1906. 
Stallings, R. E. An Examination of Whiskeys. N. Dak. Agric. Exp. Sta. Rep. 1906, 

p. 138. 
Tolman, L. M., and Hillyer, W. E. Methods of Analysis of Distilled Spirits. 

A. O. A. C. Proc. 1908. U. S. Dept. Agric Bur. of Chem., Bui. 122, p. 206. 
Tolman, L. M., and Trescot, T. C. A Study of the Methods for the Determination 

of Esters, Aldehydes and Furfural in Whiskey. Jour. Am. Chem. Soc, 28, 

1906, p. 1619. 
Vasey, S. a. Guide to the Analysis of Potable Spirits. London, 1904. 



CHAPTER XVI. 
VINEGAR. 

Vinegar is tlie product formed by the acetic fermentation of an alco- 
holic liquid under the influence of the organism mycoderma aceti, existing 
in the " mother-of- vinegar. " While vinegar may be made directly from 
a dilute solution of pure alcohol, it is more often obtained from fruit juice, 
wine, or other saccharine liquid that has first undergone alcoholic fer- 
mentation. 

Of the following equations, (i) and (2) illustrate the processes of 
inversion and alcoholic fermentation respectively, while (3) and (4) show 
the double process of acetic fermentation, wherein the alcohol is oxidized, 
first to acetaldehyde and finally to acetic acid: 

QA^Oii+H^O-aCA-A; (i) 

Cane sugar Invert sugar 

CeHi206 = 2C,H«0 + 2C02; (2) 

Invert sugar, Alcohol 
dextrose, or 
maltose 

QHeO + O^CH.O + H^O; (3) 

Alcohol Aldehyde 

C,H,0 + = C3HA. .0 (4) 

Aldehyde Acetic acid 

In addition to the acetic acid, its chief active principle, vinegar usually 
contains traces of other organic acids free or combined, small amounts 
of alcohol, aldehyde, sugar, glycerin, coloring matter, aromatic ethers, 
and mineral salts, its extract varying considerably with the source from 
which the vinegar was obtained. 

Varieties. — The principal varieties of vinegar are the following : Cider 

vinegar, wine vinegar, malt or beer vinegar, spirit vinegar, glucose vinegar, 

molasses vinegar, and wood vinegar, the three last being more frequently 

used as adulterants of the others. 

759 



760 FOOD INSPECTION AND ANALYSIS. 

Manufacture of Vinegar. — Cider vinegar, the principal variety used in 
the United States and Canada, was formerly made almost entirely by the 
slow process of cask fermentation, the fresh cider being allowed to undergo 
both alcoholic and acetic fermentation in barrels with open bung-holes in 
a warm cellar, or exposed to the sun. Two or three years are required 
for this process. Sometimes fresh cider is added to the barrels at regular 
intervals of two or three weeks, thus causing a series of progressive fer- 
mentations. The acetic fermentation is hastened by adding old vinegar, 
or mother-of- vinegar to the cider. While farmers and some manufac- 
turers still continue to make cider vinegar by the slow process, the quick 
or "generator" vinegar process is now much used for cider vinegar, 
though originally intended and almost exclusively used in the manufacture 
of malt, beer, and spirit vinegar. This process requires only two or 
three days for complete acetification. In the quick process, the cider 
or other alcoholic liquor is allowed to percolate slowly through beech- 
wood shavings or birch twigs, held in a cask known as a generator, 
provided with a perforated, false bottom, the shavings or twigs being 
previously saturated with old vinegar, and a current of air being passed 
up through them. 

The alcoholic liquid from which genuine malt vinegar is made is 
derived from the wort obtained by mashing malt, or a mixture of malt 
and barley. Spirit vinegar is derived from diluted whiskey, brandy, or 
grain alcohol. Wine vinegar is made by allowing the wine to stand over 
wine lees for a time, after which it is clarified by passing through beech 
shavings, and subjected to progressive acetification in large open oak 
casks, to which the wine is added, the vinegar being drawn off in much 
the same manner as the slow-process cider vinegar. 

Characteristics and Composition of the Various Vinegars. 
— Cider Vinegar is brownish yellow in color, and possesses an odor of 
apples. It is chiefly distinguished from other vinegar by the large amount 
of malic acid normally present, by the character of its sugars, and by the 
predominance of potash in the ash. Its specific gravity varies from 
1.013 to 1.015. Its acidity varies from 3 to 6 per cent, and its solids 
from i^ to 3 per cent. Cider vinegar under polarized light is always 
laevo-rotary. 

The following are summarized data of analyses made by H. C. Lyth- 
goe in the writer's laboratory of twenty-two samples of cider vinegar of 
known purity: 



VINEGAR 



761 









Acetic 
Acid. 


Total 
Solids. 


Ash. 


Alkalin- 
ity of 
Ash.i 


P2O6 in Ash of loo 
Grams Vinegar. 




Soluble 
(mgr.). 


Insoluble 
(mgr.). 


Maximum 


5.86 
3-92 
4.84 


3.20 
1.84 
2.49 


0.42 
0.20 
0.34 


36.1 
22.2 
29.7 


31-7 
12. 1 
19.2 


31. 5 

6-5 

15-6 


Minimum 


Average 






Reducing Sugars. 


Polariza- 
tion, 
Degrees 
Ventzke 
200-mm. 
Tube. 


Malic 
Acid. 


Per Cent 
Ash in 
Total 
Solids. 


Per Cent 
Reducing 

Sugars 
in Total 

Solids. 


Ratio of 

Soluble 

to Total 

P2O5. 


Alkalin- 




Before 
Inversion. 


After 
Inversion. 


1 Gram of 
Ash, cc. 

^ Acid. 
10 


Maximum 

Minimum. — 
Average 


0.51 

0.25 


0-53 
0-15 
0.25 


-3-6 
-0-3 
-1-3 


o.t6 
0.08 

O.II 


19.0 
10. 
13.8 


16.6 

7-3 
10.7 


66.9 
1^0. 
56-3 


125.0 
69.0 
90.0 



■ Nun-.ber of cubic centimeters of tenth-normal acid to neutralize the ash of 100 grams of vinegar. 

Twenty-two samples of pure cider vinegar were analyzed by A. W. 
Smith * with the followino; results : 



Acetic 
Acid. 



Total 
Solids. 



Ash. 



Alkalinity 
I of Ash.i 



Soluble 
P2O5. 



Insoluble 
P2O5. I 



Total 
P2O5. 



Maximum. 
Minimum. 
Average . . . 



7.61 

3-24 
4.46 



4-45 
2.00 
2.83 



0.31 
0-39 



55-2 
28.4 
38.8 



22.7 
13.6 
19. 1 



19.4 
4-2 



39-0 
19.8 
28.6 



' Number of cubic centimeters of tenth-normal acid required to neutralize the ash from 100 grams 
of vinegar. 

The composition of cider vinegar ash is found by Doolittle and Hess f 
to be as follows: 

Calcium oxide CaO 3.4 to 8.21 

Magnesium oxide MgO 1.88 " 3.44 

Potassium oxide K^O 46.33 " 65.64 

Sodium oxide NajO None 

Sulphuric anhydride. . .. SO3 4.66 to 16.29 

Phosphoric anhydride . . P2O5 3-29" 6.66 

Iron oxide FcsOs None " trace 

CO, and loss 0.00 " 40.44 

"Wine Vinegar is light yellow if made from white wine, and red if from 
red wine. The former is the highest prized. Wine vinegar varies in specific 



* Jour. Am. Cham. Soc, 20 (i 
t Ibid., 22 (1900), p. 220. 



p. 6. 



762 



FOOD INSPECTION AND ANALYSIS. 



gravity from 1.0129 to 1.02 13, and contains from 6 to 9 per cent of acetic 
acid. It is characterized chiefly by the bitartrate of potassium (cream 
of tartar) which true wine vinegar always possesses. Free tartaric acid 
is also usually present. Wine vinegar is the principal vinegar of France 
and Germany. In the United States the term white wine vinegar is 
usually applied to distilled or spirit vinegar, which is much cheaper than 
the real wine vinegar and altogether inferior to it. 

Wine vinegar is slightly laevo-rotary with polarized light. 

The composition of genuine white wine vinegar is shown by the follow- 
ing summary of the analyses of twenty-two samples, made in the Municipal 
Laboratory of Paris: 





Specific 
Gravity. 


Total 
Solids. 


Sugar. 


Bitartrate 

of Potash. 


Ash. 


Acidity 
(as Acetic). 




I. 0213 
I. 0129 
1.017s 


3-19 
1-38 
1-93 


0.46 
0.06 
0.22 


0.36 
0.07 
0.17 


0.69 
0.16 
0.32 


7-38 
4.44 
7-38 


Minimum 





Weigmann gives the following average of analyses of red wine vinegar: 



Specific 
Gravity. 


Ace tic 
Acid. 


Toial 

Tartaiic 

Acid. 


Free 

Tartaric 

Acid. 


Cream of 
Tartar. 


Alcohol. 


Extract. 


Gly- 
cerin. 


Ash. 


Phos- 
phoric 
Acid. 


I. 0143 


7-79 


0.216 


0.006 


0.057 


1. 19 


0.863 


O.141 


0.118 


0.012 



Malt or Beer Vinegar is of a brown color, and its odor is suggestive 
of sour beer. It varies in specific gravity from 1.015 to 1.025; i^s acidity 
is about the same as cider vinegar, but the extract is much larger, varying 
from 4 to 6 per cent. Malt vinegar contains considerable nitrogenous 
matter, and notable quantities of phosphates, dextrin, and maltose. It 
contains no cream of tartar. Malt vinegar is largely used in Great Britian. 

Hehner gives the following data of the analyses of seven samples 
of vinegar undoubtedly made from malt only.* 



Acidity. 



Total 
Solids. 



Ash. 



Phosphoric 
Anhydride. 



Alkalinity 
(NazCOs). 



Maximum 
Minimum. 
Mean 



6.48 
2.88 
4-23 



4-23 
1.68 
2,70 



0.47 
0.22 
0-34 



-13 

.067 

.105 



* Analyst, 16, p. 82. See also Analyst, 18, p. 240. 



.017 
.024 



yiNEGAR. 



763 



Allen gives the results of the analyses of three samples of genuine 
vinegar brewed from a mixture of malted and unmalted barley as follows:* 





Specific 
Gravity. 


Acetic 
Acid. 


Total 
Solids. 


Ash. 


Alkalinity 
as K2O. 


Phos- 
phoric 
Acid. 


Nitrogen. 


Albumin- 
oids. 


I 


I. 0170 
1.0228 
I. 0160 


6-39 
5.26 
4.86 


2.67 
3-96 
2.31 


0.34 0.091 
0.40 0.118 

d.7 


0.077 
0.093 
0.057 


.099 

-095 
.099 


.624 

.598 
.624 


2 


7. ........... 









Distilled, Spirit, or Alcohol Vinegar. — This vinegar, being made from 
diluted alcohol, is nearly colorless, unless artificially colored, as it often 
is, wiih caramel. As stated on page 762, the "white wine" vinegar (incor- 
rectly so-called) commonly sold in the United States is of this class. Its 
specific gravity ranges from 1.008 to 1.013. Spirit vinegar contains 
from 3 to 10 per cent of acetic acid. Its content of total solids is insig- 
nificant, and it contains only traces of ash. It always contains non- 
acetified alcohol and aldehyde. It has no optical activity with polarized 
light. 

Twelve samples of alcohol vinegar analyzed in the Municipal Labora- 
tory of Paris gave the following results: 



1 Specific 
1 Gravity. 


Total 
SoHds. 


Sugar. 


Ash. 


Acidity. 




1.0131 
1.0082 
I . I 00 


0.16 
0.07 
0-35 


Trace 
<< 


.09 

.04 

Trace 


7.98 
4-98 
6.34 


Minimum. 


Mean 







Glucose Vinegar is made from the acetification of alcohol, obtained 
from the fermentation of commercial glucose. This vinegar usually 
possesses the odor and taste of fermented starch. It is low in total solids, 
the extract consisting almost entirely of untransformed glucose, and the 
vinegar therefrom contains all the ingredients of the product from which 
it was made, viz., dextrin, maltose, and dextrose, as well as sulphate of 
calcium. It is decidedly dextro-rotary with polarized light both before 
and after inversion. 

Molasses Vinegar. — This is largely the product of the acetic fermen- 
tation of sugar-house wastes, and sometimes of the accidental acetic 
fermentation of molasses itself, after it has undergone alcoholic fermenta- 
tion for the manufacture of rum. This variety of vinegar is sometimes 

* Analyst, 19, p. 15. 



764 FOOD INSPECTION AND ANALYSIS. 

used as an adulterant of cider vinegar. With polari/:ed light molasses 
vinegar is dextro-rotary before, and laevo-rotary after inversion. 

Wood Vinegar is prepared by the purification of pyroligneous acid, 
which may be accomplished by saturating the crude acid w'xlh. lime or soda, 
adding hydrochloric or sulphuric acid, and distilling. It is further purified 
by redistillation with potassium bichromate, and filtration through bone- 
black. Acetic acid is sometimes added to impart flavor. 

The extract and ash of wood vinegar arc very small. Its specific 
gravity averages 1.007 according to Blyth. Empyreumatic or tarry 
products are nearly always present in vinegar of this class. 

ANALYSIS OF VINEGAR. 

Specific Gravity. — This is obtained either with the hydrometer, pyc- 
nometer, or Westphal balance. 

Determination of Extract or Total Solids. — Weigh 5 grams of the 
sample in a tared jjlatinuni dish, and evaporate to dr^'ness over the live 
steam of a boiling-water bath, keeping the dish thereon for two hours. 
Cool in a desiccator and weigh. 

Determination of Ash. — Transfer the dish containing the last residue 
or extract to a muffle, and burn at a low red heat to an ash, or the ignition 
may be accomplished with care over a direct flame turned low. Cool 
the dish and weigh. 

Determination of Solubility and Alkalinity of the Ash. — Smith's 
Method.^ — Twenty-five cc. of the vinegar are evaporated to dryness in 
a tared platinum dish, ignited, cooled, and the ash weighed. The ash is 
then repeatedly extracted with hot water by washing into a Gooch crucible 
provided with a layer of asbestos (previously ignited in the crucible, cooled, 
and weighed) or upon an ash-free filter. Dry the Gooch or filter, ignite, 
cool, and weigh the insoluble ash. The aqueous extract is titrated directly 
with tenth-normal acid, using methyl orange as an indicator, or treated 
by adding an excess of tenth-normal hydrochloric acid, boiling and titrat- 
ing back with tenth-normal sodium hydroxide, using phenolphthalein. 
Express the alkalinity in terms of 100 grams of the vinegar, by multiplying 
by 4 the number of cubic centimeters of acid required to neutralize. 

Determination of Phosphoric Acid.f — Extract repeatedly the insoluble 
ash as obtained in the preceding section with hot water acidulated with 
nitric acid, and acidify with nitric acid the neutralized solution of the 

* Jour. Am. Chem. Soc, 20, p. 5. 

t U. S. Dept. of Agric, Bur. of Chcm., Bui, 46, p. 12. 



yiNEGAR. 765 

soluble ash. Add to each solution 15 grams of ammonium nitrate, heat 
to boiling, and precipitate the phosphoric acid with 50 cc. of ammonium 
molybdate (reagent No. 53). Digest for an hour at a temperature of 
about 65°, filter, and wash with cold water. Dissolve the precipitate on 
the filter with ammonia and hot water, and wash into a beaker to a 
bulk of not more than 100 cc. Nearly neutralize with hydrochloric 
acid, cool, and add slowly magnesia mixture (reagent No. 164) drop 
by drop while stirring vigorously. After fifteen minutes add 30 cc. of 
ammonia (specific gravity 0.96), let stand for at least two hours, filter 
on a Gooch crucible, wash with 2.5% ammonia till jjraclically free from 
chlorides, ignite, and weigh as Mg^^PoOy. Express results in terms of 
milligrams of phosphoric anhydride in the soluble and insoluble vinegar 
ash from 100 grams of vinegar. 

Phosj)horic acid in the soluble and insoluble ash may be conveniently 
determined also by the uranium acetate method, page 725. 

Determination of Nitrogen. — Concentrate from 50 to 100 cc. of 
vinegar to a syrupy consistency, and proceed as directed under the 
Kjeldahl or Gunning method, jjage 69. 

Determination of Total Acidity. — Six cc. of vinegar are carefully 
measured from a pipette into a white porcelain dish and diluted with 
water. Using phenolphthalein as an indicator, titrate with tenth-normal 
sodium hydroxide. The number of cubic centimeters of the latter required 
to neutralize, divided by 10, expresses the acidity in terms of percentage 
of acetic acid. 

A pproximate Determination 0} Vinegar A cidity by Lime Water. — It 
has generally been considered difficult for vinegar dealers and others 
who desire to estimate the acidity of their vinegar to do this themselves, 
in that it has been necessary to obtain for the purpose a carefully standard- 
ized alkaline solution, the exact strength of which it is impossible for 
them to determine. 

It has been found that very satisfactory, though of course not abso- 
lutely accurate, results may be obtained by the use of ordinary lime 
water, which any one may easily prepare by making a saturated solution 
of ordinary air-slaked lime. The strength of such a solution is very nearly 
constant, and has been found to be about ^,'.4- of the normal. If, there- 
fore, it is not easy to obtain exactly normal or tenth-normal alkali, approx- 
imate figures may be obtained by employing such a saturated lime water. 
If 2.75 cc. of vinegar are titrated with lime water contained in a burette, 
using phenolphthalein as an indicator, the number of cubic centimeters 



766 FOOD INSPECTION AND ANALYSIS. 

of the lime water necessary to neutralize the vinegar, divided by lo, 
gives the percentage of acetic acid in the vinegar. To make sure that 
the lime water is saturated, an excess of lime should always be present 
in the reagent bottle. 

Determination of Volatile and Fixed Acids. — Thirty cc. of the vine- 
gar are transferred to a distilling-flask and subjected to distillation, using 
a current of steam. Receive the distillate in a 25-cc. graduated cylinder. 
After 15 cc. have passed over, test from time to time the drops of 
distillate as they fall into the receiving vessel with litmus-paper, and when 
free from acid discontinue the distillation. Note the volume of the 
distillate, mix by shaking, and transfer one-fifth to a white porcelain dish. 
Titrate as in the case of total acidity, expressing the volatile acids as 
acetic. 

Calculate the fixed acid, expressed in the case of cider vinegar as 
malic, by subtracting the percentage of volatile acid from the percentage 
of total acid, and multiplying the result by the factor 1.117. In the case 
of wine vinegar, express as tartaric acid by using the factor 1.25. To 
express acidity in terms of sulphuric acid, multiply the percentage of 
acetic acid by 0.817. 

Determination of Alcohol. — Alcohol is present in very small amounts 
in fruit vinegar tliat has not been completely acetified. Frear recom 
mends concentrating the distillates as follows: Neutralize 100 cc. of 
the sample and distill off 40 cc. Then redistill the distillate till 20 cc. 
have gone over. Cool to 15.6° C. and make up to 20 cc. with distilled 
water. Determine the specific gravity with a lo-cc. pycnometer, and 
ascertain from the table on page 661 the per cent by weight of alcohol 
corresponding to the specific gravity. The percentage in the last distil- 
late, divided by 5, expresses the amount of alcohol in the vinegar. 

Detection of Free Mineral Acids. — The ash of genuine cider vinegar 
is always alkaline. If the ash is neutral, free mineral acids are doubtless 
present. For their detection the following is a modification of Brannt's 
method of procedure: 

Add to 50 cc. of the vinegar in an Erlenmeyer flask a small bit of 
starch the size of a wheat-grain, and shake to disseminate it through the 
fluid. Boil for some minutes, cool, and add a drop of iodine solution. 
If a blue coloration occurs, no mineral acid is present. In the presence 
of an appreciable amount of mineral acid, the starch will be converted 
to dextrin and sugar, and no coloration will be produced by the iodine. 

Frear^s Method-. — Add 5 or 10 cc. of water to 5 cc. of the vinegar, and 



VINEGAR. ^t^J 

to the mixture add a few drops of a solution of methyl violet (one part 
of methyl violet 2B in 100,000 parts of water). In the presence of mineral 
acids, a blue or green coloration will be produced. 

Determination of Free Mineral Acids. — Kehnefs Method.*— To a 
weighed c^uantity of the sample add an excess of decinormal alkali, evap- 
orate to dr^'ness, incinerate, and titrate the ash with decinormal acid. 
The difference between the number of cubic centimeters of alkali added 
in the first place, and the number of cubic centimeters needed to titrate 
the ash, represents the equivalent of the free acid present. 

Detection and Determination of Sulphuric Acid. — This is determined 
as barium sulphate by the addition of barium chloride solution. A slight 
cloudiness on the addition of the reagent indicates the presence of 
small quantities of sulphate as an impurity, rather than free sulphuric 
acid. If a minute quantity of free sulphuric acid be present, a rather 
heavy white cloud on the addition of the barium chloride will be formed, 
which slowly settles out. According to Brannt, if the quantity of sul- 
phuric acid is more than one part in a thousand, the sulphate of barium 
formed by addition of the reagent produces a copious precipitate that 
rapidly falls to the bottom of the receptacle. This may be filtered, 
washed, ignited, and weighed in the usual manner. 

Detection of Free Hydrochloric Acid. — Distill off half of a measured 
volume of vinegar into the receiving-flask of a distillation apparatus, 
and to the distillate add a few drops of nitrate of silver reagent. A pre- 
cipitate indicates hydrochloric acid. 

Detection of Malic Acid {Free or Combined). — Absence of malic acid 
may be assured, if no precipitate occurs with neutral acetate of lead, 
when a few drops of a solution of this reagent are added to the vinegar. 
In the presence of malic acid, as in the case of a pure cider vinegar, the 
precipitate which is formed with lead acetate is flocculent, forms at once, 
and is of considerable amount. In pure cider vinegar the precipitate 
will settle to the bottom of the test-tube, leaving a clear supernatant 
liquid within ten minutes. Unfortunately the acetate of lead test is 
a negative one, in that several organic acids other than malic will cause 
a precipitate, as, for instance, tartaric and saccharic acids, the former 
being found in wine and the latter in molasses vinegar. Malt vinegar 
also gives a copious precipitate with lead acetate, clue to phosphoric acid. 

The writer employs the following test t for detecting malic acid in 

* Analyst, i, 1877, p. 105. 

t An. Rep. Mass. State Board of Health, 1902, p. 485. Food and Drug Reprint, p. ;i^. 



768 FOOD INSPECTION /1ND AN /i LYSIS. 

vinegar: Add a few drops of a io% solution of calcium chloride to some 
of the vinegar in a test-tube, and make the mixture slightly alkaline with 
ammonia. Filter off the precipitate that occurs at this point, to the 
filtrate add two or three volumes of 95% alcohol, and heat to boiling. 
A copious, flocculent precipitate of calcium malate will form, if malic 
acid be present, settling to the bottom of the tube in a few minutes. 
A precipitate will occur in malt and glucose vinegar, due to dextrin. 

To confirm the presence of malic acid, filter, wash the precipitate 
with a little alcohol, dry, dissolve it in strong nitric acid in a porcelain 
evaporating-dish, and evaporate to diyness over the water-bath, forming 
calcium oxalate. Boil the residue with sodium carbonate, filter, acidify 
the filtrate with acetic acid, boil to expel the carbon dioxide, and add a 
solution of calcium sulphate. A precipitate of calcium oxalate confirms 
the presence of malic acid. 

For the determination of malic acid proceed as directed on page 702. 

Lead Precipitate. — Hortvet Number. — The quantitative measurement 
of the precipitate formed with lead acetate, or subacetate, is of con- 
siderable importance. Even though the precipitate formed may not be 
due as was long thought to malic acid, but may be due to phosphoric 
acid (though this has not been fully proved), it nevertheless remains a 
fact that the qualitative lead acetate test is one of the most important 
of all in judging the purity of cider vinegar. 

The lead precipitate is best measured as follows: To 25 cc. of the 
vinegar add 2.5 cc. of U. S. P. subacetate of lead solution. Shake and 
whirl in a graduated Hortvet tube in the centrifugal machine, and read 
the volume of the precipitate in the bottom of the tube. The results 
expressed in cc. on thirty samples of pure cider vinegar are summarized 
as follows: Highest, 1.4; lowest, 0.5; average, 0.84. The lead number 
of adulterated cider vinegar runs from a mere trace to 0.5 and some- 
times higher. 

Winion's Lead Number. — This is determined by the method de- 
scribed for maple products, page 628. 

Bailey* obtained by this method the following results: 

Cider vinegar (8 samples) o-075 to 0.290 

Malt vinegar (3 samples) o. 158 to o. 548 

Distilled vinegar (i sample) 0.018 

*A. O. A. C. Proc, 1908. U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 27. 



VINEGAR. 769 

Hickey * follows the same method, except that he employs only 5 cc. 
of standard lead subacetate solution and determines the lead in 50 cc. 
of the filtrate. The lead number found by him in twenty samples of 
cider vinegar varied from 0.076 to 0.166. 

Determination of Acid Tartrate of Potassium. — Berthelot and Fleu- 
rien's Mc//;o(/.t— Twenty-five cc. of the vinegar are evaporated on the 
water-bath to syrupy consistency, and the residue is dissolved in water 
and made up to its original volume. It is then transferred to a 250-cc. 
Erlenmeyer flask, and 100 cc. of a mixture of equal parts of strong alcohol 
and ether are added, the flask is corked, shaken, and set on ice or in a 
cold place for forty-eight hours. At the end of this time, if a crystalline 
precipitate has gathered, the supernatant liquid is decanted upon a filter, 
and finally the precipitate is washed upon it by a fresh quantity of the 
ether-alcohol mixture, and the washing continued with this reagent till 
practically free from acid. The filter and its contents are then trans- 
ferred to the original flask, and the tartrate is dissolved in boiling water, 
after which the solution is titrated in the same flask with tenth-normal 
sodium hydroxide, using phenolphthalein as an indicator. Multiply 
the number of cubic centimeters of alkali required to neutralize by the 
factor 0.0188, and the quotient expresses the grams of bitartrate of potash 
in the sample. Multiply this by 4 to obtain the percentage present. 

Polarization and Determination of Sugar. — If the vinegar is light- 
colored and quite free from turbidity, it may sometimes be polarized undi- 
luted in the loo-mm. tube. Vinegar may often be sufficiently clarified 
for polarization by filtering twice through the same filter. It is, how- 
ever, best to add 10% of basic lead acetate solution, and to filter before 
polarizing, thus removing the malic or tartaric acids which may have a 
slight effect on the polarization. In case of dark-colored or turbid 
samples, add to 50 cc. of the sample 5 cc. of about equal quantities of 
lead subacetate and alumina cream, shake, filter, and polarize in a 200- 
mm. tube, adding 10% to the reading on account of the dilution. 
The polarization value of the vinegar is conveniently expressed in terms 
of actual direct reading obtained by the undiluted sample in a 200- or 
400-mm. tube. 

If the invert reading is desired for calculation of sucrose or com- 
mercial glucose, subject the sample to inversion with hydrochloric acid 
and heat, as in the case of sugars. 

* Ibid. 

t Girard et Dupre, Analyse des Matieres Alimentaires, p. 12E. 



770 FOOD INSPECTION AND ANALYSIS. 

For the determination of sucrose, use Clerget's formula (p. 588), 
calculating the true direct and invert readings from the direct and invert 
readings of the undiluted vinegar on the basis of the normal weight of 
the sample, by multiplying the obtained readings by 0.26 in the case of the 
Soleil-Ventzke instrument. 

Datermination of Reducing Sugars before and after Inversion. — Two 
portions of 25 cc. each are measured into loo-cc. flasks. One portion is 
diluted with 25 cc. of water, 5 cc. of concentrated hydrochloric acid are 
added, and the solution subjected to inversion by heating to 70° for 10 
minutes and cooling. Both portions are neutralized with sodium 
hydroxide and made up to the mark. The reducing sugars are deter- 
mined in each portion by Defren's modification of O 'Sullivan's method 
(page 594) and calculated as dextrose. 

Levulose may be determined as on page 626, polarizing the vinegar 
at two different temperatures. 

ADULTERATION OF VINEGAR. 

Standards of Purity. — In nearly all localities where pure-food laws 
prevail there are special provisions setting forth the requirements of pure 
vinegar as to percentage of acids, solids, and other conditions, differing 
considerably with the character of the vinegar used. Thus, in England,, 
where the principal vinegar is malt vinegar, the legal standards are con- 
siderably different from those in force in France and Germany, where 
wine vinegar is prevalent. These differ again from the requirements 
found in the United States and Canada, where cider vinegar is the chief 
product. 

Most of the state food laws fix a standard for the acidity of cider 
vinegar varying from 3.5 to 4.5 per cent of acetic acid, and in most cases 
also a minimum standard for total solids or residue of from 1.5 to 2 per 
cent. Special laws stipulate furthermoie in some states that cider vine- 
gar, sold as such, must be exclusively the product of pure apple cider. 
In such cases cider vinegar may be adulterated by non-conformance 
to the standard in either acidity or solids or both, while yet it may be 
exclusively made from pure apple cider. This may be dvc either to 
actual watering or to incomplete acetification. On the other hand, so- 
called cider vinegar may be of legal standard as to solids and acidity, 
and yet be entirely spurious. 



I^INEG^R. 771 

Following arc the U. S. standards for the various vinegars: 

Vinegar, Cider Vinegar, Apple Vinegar, is the product made by the 
alcoholic and subsequent acetous fermentations of the juice of apples, 
is la?vo-rotatory, and contains not less than 4 grams of acetic acid, not 
less than 1.6 grams of apple sohds, of which not more than 50% are 
reducing sugars, and not less than 0.25 gram of apple ash in 
100 cc. (20° CO ; and the water-soluble ash from 100 cc. (20° C.) of 
the vinegar contains not less than 10 milligrams of phosphoric acid 
(P2O5), and requires not less than 30 cc. of decinormal acid to neutralize 
its alkalinity. 

Wine Vinegar, Grape Vinegar, is the product made by the alcoholic 
and subsequent acetous fermentations of the juice of grapes, and con- 
tains in 100 cc. (20° C), not less than 4 grams of acetic acid, not less 
than i.o gram of grape solids, and not less than 0.13 gram of grape 
ash. 

Malt Vinegar is the product made by the alcoholic and subsequent 
acetous fermentations, without distillation, of an infusion of barley malt, 
or cereals whose starch has been converted by malt, is dextro-rotatory, 
and contains, in 100 cc. (20° C), not less than 4 grams of acetic acid, 
not less than 2 grams of solids, and not less than 0.2 gram of ash; and 
the water-soluble ash from 100 cc. (20° C), of the vinegar contains not 
less than 9 milligrams of phosphoric acid (P2O5), and rec|uires not less 
than 4 cc. of decinormal acid to neutralize its alkalinity. 

Sugar Vinegar is the product made by the alcoholic and subsequent 
acetous fermentations of solutions of sugar, syrup, molasses, or refiners' 
svrup, and contains, in 100 cc. (20° C), not less than 4 grams of acetic 
acid. 

Glucose Vinegar is the product made by the alcoholic and subsequent 
acetous fermentations of solutions of starch sugar or glucose, is dextro- 
rotatory, and contains, in 100 cc (20° C), not less than 4 grams of acetic 
acid. 

Spirit Vinegar, Distilled Vinegar, Grain Vinegar, is the product made 
by the acetous fermentation of dilute distilled alcohol, and contains, in 
100 re. (20° C), not less than 4 grams of acetic acid. 

Accidental Adulteration of vinegar may result in the presence of injuri- 
ous metallic salts, such as of copper, lead, or zinc, derived from vessels or 
utensils used in the manufacture of vinegar, or even minute trace;; of 
arsenic may be found, when glucose has been employed a:, an ingredient 



772 FOOD INSPECTION AND ANALYSIS. 

or source of the vinegar, the arsenic being in this case probably due to 
impure sulphuric acid used in llie manufacture of the glucose. 

Willful or Fraudulent Adulteration is, however, common, in which 
mis])rande(l vinegar is sold under names suggesting a class other than 
that to which it really belongs, or wherein entirely artificial substitutes 
are made up for pure cider, malt, or wine vinegar, in which the color, 
residue, and acid principle may be either or all of spurious origin. 

Artificial Cider Vinegar is in most cases readily detected, though 
very ingenious imitations are on the market, involving not a little skill 
and chemical knowledge in their manufacture. 

Entirely artificial substitutes for cider vinegar are frequently made 
up of spirit vinegar, colored with caramel, and having the solids rein- 
forced by apple jelly, made for the most part out of exhausted apple 
pomace, which is the residue left after the apple-stock has been sub- 
jected to one and sometimes two pressings. The jelly used for this 
purpose is not infrequently made up with commercial glucose. All 
grades of adulterated vinegar are to be found, from the wholly 
spurious substitute above described, to the varieties in which cider 
vinegar is itself present, but is pieced out or reinforced by the admixture 
of coloring matter, mineral acid, wood vinegar, or of molasses or glucose 
vinegar. x\cetic ether is sometimes employed to impart flavor to the 
product. All the characteristics of a pure cider vinegar are difficult to 
duplicate artificially, though some of them may be. 

Character of the Residue. — The residue of pure cider vinegar should 
be thick, light brown in color, of a viscid or mucilaginous consistency, 
somewhat foamy, ha\'ing an astringent acid though pleasant taste very 
suggestive of baked apples, which it also resembles in odor. Tlic odor 
of molasses is very apparent in the residue of vinegar having sugar-house 
wastes, and the smell of a malt-vinegar residue is also very characteristic. 
If pyroligneous or wood vinegar has been introduced, the dried residue 
v^ill have a tarry or smoky taste and smell. 

The residue of cider vinegar is very soluble in alcohol, while that of malt 
vinegar is only slightly soluble. Wine vinegar residues dissolve readily 
in alcohol, except for the granular residue of cream of tartar. If the 
loop of a clean platinum wire be rubbed in the vinegar residue and ignited 
in a colorless Bunsen flame, the color imparted will, if the vinegar has 
been made from pure cider exclusively, consist altogether of the pale- 
lilac color of a potash salt without any of the yellow sodium flame being 



FIN EG ^R. TJ3 

visible. In all vinegars other than of pure cider, the sodium flame will 
predominate, when the residue is burnt as above. Again, the ignited 
residue left in the loop of wire in the case of a pure cider vinegar will 
form a fusible bead, having a strong alkaline reaction upon moistened 
test-paper, and effervescing briskly when immersed in acid. The pres- 
ence in vinegar of even a slight trace of added mineral acid will prevent 
the ignited residue from having the alkaline reaction, or effervescing with 
acid.* 

The residue of malt or beer vinegar is brown and gummy, containing 
a considerable quantity of dextrin. Not only are the appearance and 
odor of the dried vinegar residue to be particularly noted, but also the 
odor given off in the first stages of burning this residue to an ash. With 
cider vinegar the apple odor is very marked while burning. In vinegar 
wherein molasses products have been employed, the smell of charred 
sugar is usually apparent, while with glucose vinegar the smell of burnt 
corn predominates. 

On burning the residue of malt vinegar, the odor produced at first 
is not unlike that of toasted bread. At a later stage in the burning the 
vapors evolved arc ver)' pungent. 

The Character of the Ash is of considerable importance in determin- 
ing the source of a sample of vinegar. The ash of pure cider and malt 
vinegar is quite strongly alkaline, while that of distilled and wood vinegar 
is only slightly alkaline. The ash of cider vinegar is high in alkaline 
carbonates. 

In cider and malt vinegar the quantity of phosphoric acid present 
in the ash is considerable, while only traces are present in distilled or 
spirit vinegar. Considerably moic than half the phosy)horic acid in 
the ash of cider vinegar is soluble, while no soluble phosphoric acid is 
present in the ash of spirit vinegar. 

The percentage of ash in total solids is of some value in judging the 
purity of cider vinegar. According to Frear.j if the ash of the vinegar 
is less than io% of the total solids, the vinegar may be suspected of 
having added unfermented material, while a percentage of ash less than 
6 is absolute evidence that the vinegar is not genuine cider vinegar. 

The alkalinity of i gram of the ash of pure cider vinegar should be 



* Davenport, i8th An. Rep., Mass. Board of Health, 1887, p. 159. 
t Report of Penn. Dept. of Agric, 1898, p 38. 



774 FOOD INSPECTION AND ANALYSIS 

equivalent to at least 65 cc. of tenth-normal add. At least 50% of 
the phosphates in the ash should be soluble in water. 

Character of the Sugars.— One of the most important steps in es- 
tablishing the source of a vinegar consists in subjecting it to polariza- 
tion (p- 769). From the nature of the sugar-content of the apple juice, 
not only when freshly expressed, but also when allowed to undergo 
alcoholic fermentation, and, furthermore, after it has gone over into 
vinegar, the polarization through all three stages is always left-handed. 

Browne * has shown that the optical rotation of the freshly expressed 
juice of eleven varieties of apple varies from 19.24° to 49° to the left on 
the Ventzke scale, in a 400-mm. tube. Also that in the case of five 
samples of completely fermented cider, examined five or six months 
after pressing, the left-handed rotation in a 400-mm. tube varied from 
1.76° to 5.28°. He showed, furthermore, that a sample of pure cider 
jelly made up of concentrated apple juice had a left-handed rotation 
amounting to 21.35° i^ ^ 200- mm. tube (20 grams made up 100 cc), and 
finally that four cider vinegar samples of known purity showed left- 
handed readings of from 0.96° to 2.94° Ventzke in a 400-mm. tube. 

The left-handed rotation of pure cider vinegar is a characteristic so 
fixed and unalterable that a right-handed polarization of more than 0.5° 
may safely be assumed as evidence of adulteration. The polarization of 
cider vinegar, expressed in terms of 200 mm. of the undiluted sample 
should lie between —0.1° and —4.0° Ventzke. If the direct polarization 
of a sample of vinegar is right-handed, while the invert is left-handed, 
sugar-house wastes or molasses may be suspected as an adulterant. 

If both direct and invert readings are right-handed, commercial 
glucose is undoubtedly present. If the polarization of the vinegar is 
far to the left, unfermented cider jelly has probably been used to rein- 
force the solids. 

Frear regards the ratio of reducing sugars after inversion to total 
solids as a useful factor in discriminating between pure cider vinegar 
and the common artificial substitutes in which the solids of distilled vinegar 
are reinforced by apple jelly, or in which commercial glucose or molasses 
vinegars are used. When the reducing sugars after inversion form more 
than 25% of the entire solids, the alleged cider vinegar is undoubtedly 



* Bull. 58, Penn. Dept. of Agric, "A Chemical Study of the Apple and Its Pro- 
ducts." 



yiNEGAR. 



775 



spurious. In pure cider vinegar the per cent of reducing sugar is 
the same after inversion as before. The same is true of glucose 
vinegar 

Vinegar containing added molasses or cane sugar will, however, 
naturally show an increase in reducing sugar after inversion. 

A large content of alcohol in cider vinegar, otherwise showing the 
•constants of pure vinegar except for the low acidity, would indicate incom- 
plete acetification. A high content of nitrogen is characteristic of malt 
vinegar. 

Data of analyses of samples of vinegar examined in the Food and 
Drug Department of the Massachusetts State Board of Health are given 
in the tables on this page and the next. The table below shows in sum- 
marized form the results obtained from the examination of eighty-four 
samples of undoubtedly pure cider vinegar examined in 1901.* 

CIDER VINEGAR FOUND PURE. 





Acid Solids 
(Per Cent). (Per Cent). 


Ash 
(Per Cent). 


Polarization. 


Maximum 


6.36 

4.50 
4-84 


4.00 
2.01 
2.43 


0.58 
O.IQ 
0.38 


-5-4 
— 0.4 


Minimum 


Mean 


— 2.0 







The second table includes samples of adulterated vinegar, sold for 
cider vinegar, none of which were probably made from cider. It will 
be noticed that in several of the samples the amount of glucose was 
abnormally large, as is shown by the very high right-handed polarization, 
in one case amounting to over 12°. 

Direct Tests Made on the Vinegar. — The genuine or spurious nature 
of cider vinegar may usually be established by direct tests with reagents 
on the vinegar itself. The appearance, taste, and odor of the vinegar 
should be noted. Brannt f applies the test of odor in vinegar as deter- 
mining its character, by rising out a large beaker with the sample, and 



* 32d An. Rep. figoo), p. 66r, Food and Drug Reprint, p. 44; 33d An. Rep. (1901), p. 
467, Food and Drug Reprint, p. 47; 34th An. Rep. (1902), p. 483, Food and Drug Reprint, 



p. 31 



t A Practical Treatise on the Manufacture of Vinegar, p. 219. 



T]ti I'OOl) INSPECTION .-IND AN. 4 LYSIS. 

VINEGAR NOT rill': ICXCLUSIVI'; I'RODIK'I' OF I'URI': Ai'l'Ll', CIDER. 



Per C.Mit 
Acctii' A. 1(1. 


P.-r CiMit. 

•l'.,lul Soluls. 


Pit Cfiit 

Ash. 


Per Cfiil 

Ash in Tulul 

Solitls. 


Polnrizatiiin 

in 200-nnn. 

Tubf. 


Lia.l Acflntf. 


5.00 


.40 


.... 


. . « • 


+ 1.4 


No ])recipitale 


5. 1-1 


..^6 


.... 




.0 


i i 11 


5 ■ ' - 


•5.? 






+ .f) 


' * ' 


-t-><S 


3-7° 


•3-' 


i^'.b's 


+ H.o:: 


' * * ' 


.|.S.. 


2. 71 


•13 


4. Ho 


-1 <).(•:: 


Ilfa\ V prccipilatc* 


-I.So 


1.07 


.30 


10. 15 


-f .<) 


I'm ipitatr 


4. So 


'•o.? 


.27 


14-75 


4 1 . 1 


* ' 


.) . ()() 


2.()J 


• 20 


6.4() 


+ -•.-' 


No pici ipilato 


4 . <)0 


-•■S7 






+ 2.0 




'|.5f' 


2 . 60 






+ 7-o:t 


t 


4 • SI 


.5 •07 


.It) 


4.'7S 


+ 5.6 


No pici i|)il;iU' 


4 -SI 


}, ■ oo 


.33 


0-7-' 


+ 5-0 


• • tt 


4-54 


2.04 


•^3 


7.8. 


+ 5.0 




4 • 54 


■J. 70 


•^3 


.S.5. 


+ .4 


I'ri'cipiliilf 


4 • 5° 


.^ ■ 05 






+ 2.2 


No pict ipitate 


4-50 


J.(;j 


.-'.; 


7-52 


+ .0 


" " 


4 - 50 


2.(.() 






+ 2.S 


II II 


4-4« 


_^.So 






+12.0t 




4-4^' 


I'. So 


.... 




+ 2.6 


It it 


4 • 1 - 


-■75 




.... 


+ 3--' 


Slii^lil ]irc< ipitate 


4 ■ 4 - 


-• . ii> 


.... 


.... 


+ 0.2 


j'lfi ipilalf 


4-1" 


-• • 5 ' 


.JO 


11.15 


+ 1.1 




4..(o 


.07 


.... 




+ -4 


No pifi ii)ilati' 


4 ■;>•*< 


.-•<) 






4-1.6 




4-,>- 


.70 


.0() 


I J . 86 




" " 


4.0H 


^■^s 


.... 


.... 


+ 1.2 


I'lvi i|)ilate 


3-98 


■ ss 




.... 


+ 1.8 


Slij^ht |)recipilate 



* Ciller viiU'Kur li> wliii li appl,' idlv I'.inliiiiiiTiK' Klui'ose Imil ]<rr\\ .ulili'il I'mi- ihf inirpnsf nf inrrens- 
inK llit^ solids fil'tiM- wiUtM'inn. 

t This siimplf I'onl.iiiiifil ii liirK'f anvnint of phosphiite, nml i-onsi-q\u-nll v Iho test lor niiiliilfS is 
iihsi'uivil. . . .... 

t 'Phfso sun-.ples polurizfil priu'ticuUy the same after as betoro inversion, iiuheatinK much K'Uicose. 

after allowini!; il U> stand for somi' hours, fxamininL!; llu- fi'W drops ri-inain- 
ing in llu- hraki'r. 'Tin- aci-lii' at id liaviii!!, for llu- most pari binonic 
volatili/.i'd, thf t liarat U'ristit \ iiioiis odor t>f piuf wiiif \iiu'L!;ar would 
at tliis stagi' br vi'iy jironiiiK-nl, while Iha! tif titU-r \iiu\<^ar would be 
entiri'ly different. The otlor of thi- two \inei;ars is \t'ry similar in their 
on^inary state. The peiuliar fruity llaxtir t)f pure t itier \inej^ar is \ery 
characteristie and not reailily imitated by cheaper substituli-s. Only 
a very slight turbidity shouUl be iirodiieed in pure t ider \ineu;ar by the 
addition of either ammonium oxalate (aliseiu t- of liiue), barium ehlt)ri(le 
(absiMUi' of sulphurif at id or sulphate), ami niliale iii sib'er (absence 
t)f hydroehlorie acid cu" chlorides). 

Vinet^ar in which glucose has been used nearb' always ,uives a precipi- 
tale with ammonium oxalate, due tt) ihe sulphate t>f calcium pic-sent. 



yiNEG/IR. 777 

The cliitraclcr of llic |)iC( i])il;ilf |)i()«lii( Cfl !)v iiciilral lead actlalc 
sliould l)c |)arlicularly nolcd. Uiili-ss il is llorculciil and coijious, scl- 
llinj; oul after a few niiinilcs, ( idcr vincf^^ar is not pnic, cviii if a marked 
liirbidily is j)r()(lii(cd. Added ai)i)le jelly from exiiausled apple |)oma(i' 
j^dvc'S such a turbidily, and is lo he siispe( led wlieii nol more than a ( loiidi 
ness is produced on addilion of llu- lead acclale rea^enl. I*ure cider 
vinef^ar should respond in a perfeelly normal manner lo holh the lead 
aeelale and Ihe (ah iinn ( hloride lesls for malic acid. 

Wood Vinegar or Pyroligneous Acid is somelinns rendered ap|)arent 
hy Ihe emp}reumali( oi- lai-ry lasli- and odor im|)arle(I lo ihe product. 
When, however, the added acetic acid has heen so purified that Ihe tarry 
laste and odor are lac kin[^, its presence may often he pro\ed hy the traces 
of furfurol which always accompany it. 

'/'est jor J''urfnnil. A little of Ihe vine^Mr is s.uhjec lecl to disi ilial ion, 
and lo the lu'sl few drops ol Ihe dislillale is added a lillle colorless anilin 
sohition. A ladiiif^ crimson color will he prodmed in presence of furfurol. 
This real I ion may somelimes heohlainecl upon the vinej^iiar itself without 
disl illal ion, il sulh( ieni added v\iiod \■inef^■|r he present. 

The lu'.t portion ol ihe dislillale of wood \ine)';ar reduces permanj^a- 
n;i1e of potassium to a marked decree. 

The Addition of Spices to vinc•)^ar in order to inc reasc- the punjj;ency 
is l)est detecled hy first neul rali/inj', i he \iiiej;ar wilh sodium (arhonale 
and then taslini^. Under these conditions, ihe admi\lure of spices is 
rendered \eiy apparent. 

Detection of Caramel. Consiclerahle added caram(I in vine^'ar is 
appareiil from llic iMuialurallv cLiik <olor and exlrenielv hiller taste- of 
Ihe residue after evaporation. 

Tests for caramel made on the vineJ^lr lesidue, if long dried at the 
temperature of the- walei- hath, are nol lo he depended on as establishing 
the |)resence of added caramel, since at that temperature the cle(oiiiposi- 
tion of the sugar may in any event cause a j)ositive lest. 

("aranu'l is delected hv ( Tampion and Simon's nni] Amlhor's tests (p. 
752). A furlher inchcatioii olcaramc-l is ihc ledncm;', power ol ihc walcr 
' hilion c)f ihc prec ipilale ohtainecl in Amlhor's lest. 

Examination for Metallic Impurities, f.ccd (ind Zinc are hest looked 
for in the ash of Ihe vinegar in ( ases where, like c ider vinegnr, the percent- 
age of (sxtract is high. A large- volmne of the- vine/^ar i:. evaporated lo 
substantial dryness over the water bath. This may most readily be 
done in a icx>-cc. |)lalinuni wine-shell, adding the vinegar in successive 



778 FOOD INSPECTION AND ANALYSIS. 

portions. To tht residue add a small amount of sodium hydroxide, and 
bum to an ash in a muffle, or over a low flame, using potassium nitrate 
if necessary, a little at a time. Take up the ash in dilute hydrochloric 
acid, and examine for lead and zinc as in the case of canned goods. 

In the case of vinegar low in extract, as in spirit vinegar, the sample 
may be evaporated to dryness, the residue dissolved directly in dilule 
hydrochloric acid without ignition, and the acid solution subjected to 
direct examination for lead and zinc. 

Copper is best determined by electrolysis. loo cc. of the vinegar 
are evaporated to a volume of about lo cc. with a little sulphuric acid, 
filtered into a platinum dish, and subjected to electrolysis, using con- 
veniently the apparatus described on page 608. 

Arsenic. — Boil down a portion of the vinegar, to which concentrated 
nitric acid has been added, to a small volume, then add a few cubic centi- 
meters of concentrated sulphuric acid, and continue the heating till fumes 
of sulphuric acid show the nitric to have been driven off. Cool, dilute 
with water, and test in the Marsh apparatus. 

REFERENCES ON VINEGAR. 

Allen, A. H. White Wine Vinegar. Analyst, 21, 1896, p. 253. 

Allen, A. H., and Moor, C. G. Vinegar. Analyst, 18, 1893, pp. 180 and 240. 

Bersch, J. Die Essigfabrikation. Vienna, 1895. 

Brannt, W. Vinegar, Acetates, Cider, Fruit Wines and Preservation of Fruits. 

London, 1900. 
Browne, C. A. A Chemical Study of the Apple and Its Products. Penn. Dept. of 

Agric. Bui. 58, 1899. 
The Effects of Fermentation upon the Composition of Cider and Vinegar. Jour. 

Am. Chem. Soc, 25, 1903, p. 16. 
Crampton, C. a., and Simons, F. D. Detection of Caramel in Spirits and Vinegar. 

Jour. Am. Chem. Soc, 21, 1899, p. 355. 
Davenport, B. F. Analysis of Vinegar. Chem. News, 1887, 3 and 66. 
DooLiTTLE, R. E., and Hess, W. H. Cider Vinegar, Its Solids and Ash. Jour. Am. 

Chem. Soc, 22, 1900, p. 218. 
Dubois, W. L. The Fuller's Earth Test for Caramel in Vinegar. Jour. Am. Chem. 

Soc, 29, 1907, p. 75. 
Frear, W. Apple Juice, Fermented Cider and Vinegar. Penn. Dept. of Agric. 

Rep., 1898, p. 138. 

Cider Vinegars of Pennsylvania. Penn. Dept. of Agric, Bui. 22, 1897. 

Vinegar. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 62. Washington, 

1902. 
Gardner, J. Acetic Acid and Vinegar. Philadelphia., 1885. 
JLeach, a. E., and Lvthgoe, H. C. Cider Vinegar and Suggested Standards of 

Purity. Jour. Am. Chem. Soc, 26, 1904, p. 375. 



ARTIFICIAL FOOD COLORS. 779 

Leeds, A. R. Acetic Acid in Vinegar. Jour. xA.m. Chem. Soc, 17, 1895, p. 741. 
Macf.arlane, T. Vinegar. Canada Inl. Rev. Dept., Bui. 35. Ottawa, 1893. 
Pasteur, M. Etudes sur la \'inaigre. Paris, 1868. 
Sangle-Ferriere. Vinaigre. Analyse des Matieres Alimentaires (Girard et Dupre). 

P- 237- 
Smith, A. W. Vinegar Analysis and Characteristics of Pure Cider Vinegar. Jour. Am. 

Chem. Soc, 20, 1898, p. 3. 
Sykes, W. J. Detection of Adulteration in Vinegar. Analyst, 16, 1891, p. 83. 

Connecticut Exp. Sta. An. Reports, 1897, 1898, 1899. 

Massachusetts State Board of Health, An. Reports, 1900, 1901, 1902, and 1903. 

North Carolina Exp. Station Bui. 153. 



CHAPTER XVII. 
ARTIFICIAL FOOD COLORS. 

The use of artificial dyestuffs in food products has greatly increased 
during recent years, both in degree and in variety of colors employed. 
Where formerly but a few well-known coloring matters, chiefly so-called 
vegetable colors and occasionally mineral pigments were used for this 
purpose, a vast array of dyes, chosen largely from the coal-tar colors, 
are now found in food, so that at present the exact identification of the 
particular dyestuff employed in all cases presents a somewhat formidable- 
problem to the analyst. The problem may consist in determining the 
class to which a commercial food color or combination of colors belongs, 
or it may consist in isolating the color itself, and afterwards identifying 
it as far as possible, for the purpose of determining whether or not it is 
harmless within the meaning of the law. 

The effect of imparting to the cheaper varieties of jellies, jams, and 
ketchups which flood the market such intense and striking colors that 
these products in no wise resemble their pure uncolored prototypes, has 
a tendency in many cases to mislead the public into the idea that the 
genuine products are inferior by contrast, and to create a craving for 
unnaturally colored varieties. Indeed, the adherents to the free use of 
coloring matters in food assert that these brilliant hues please the eye and . 
are hence legitimate. 

Objectionable Features. — With the exception of confectionery and 
certain dessert preparations, in which dyes may be employed purely for 
aesthetic considerations only (a fact which is well understood by the 
consumer), the use of coloring matters in food is mainly for the purpose 
of deceiving as to their true character. The use of dyestuffs in food 
is objectionable on two accounts, first as introducing in some cases 
materials injurious to health, and second, in nearly all cases as deceiv- 
ing the purchaser by concealing inferiority, or by making the goods 

780 



/IRTIFICIAL FOOD COLORS. 781 

appear of greater value than they really are. In most states the food 
laws regarding employment of colors are so framed, that the presence 
of such colors constitutes an offense under one or the other of the above 
heads, mainly, however, because, by reason of their use, cheaper or 
inferior materials are made to masquerade for the higher or genuine 
grades, as, for instance, when alleged currant jelly is found to consist 
chiefly of apple-stock and commercial glucose, colored with an artificial 
red dye. 

In such cases the analyst has merely to prove conclusively that an 
artificial color is present, even if he does not identify the dye itself. It 
is of course more satisfactory to at least show in addition whether the 
dye present is of vegetable origin, or is of the coal-tar variety, and in most 
cases this can readily be done, even if it is not easy to identify the exact 
color. 

In localities where laws prevail stipulating that what are commonly 
known as "mixtures" or "compounds" to be legally sold, must be 
labeled with the names and percentages of ingredients, the law applies to 
coloring matters as well as other ingredients, and the exact dye or dyes 
employed should appear on the label. Otherwise the product must be 
classed as adulterated. 

Toxic Effects of Colors. — Formerly the use of such pigments as 
chromate of lead was common in coloring confectioner}^, but lead 
chromate is rarely used at present. Other mineral pigments obviously 
unfit for use in food by reason of their well-known poisonous effects are 
those which contain salts of arsenic, mercury, lead, and copper. While 
most of the coal-tar colors are considered harmless in themselves, some 
are decidedly objectionable, and should not be used in foods. Under 
the latter class are included, first, those in connection with the manu- 
facture of which arsenic, mercury, or other poisonous mineral ingredients 
have been used, such for example as arsenical fuchsin, and, second, those 
which are themselves inherently poisonous, as for instance picric acid. 
Fuchsin is now largely made without the aid of arsenic acid, and this 
variety is, perhaps, harmless. The toxic effects of many of the coal-tar 
colors have not been thoroughly established excepting in a negative way. 
Weyl has made many experiments on dogs and rabbits in which these 
animals have been fed with varying amounts of coloring material. In 
nearly all cases the doses far exceeded the amounts ordinarily taken in 
food, and the experiments are of value mainly in so far as they show 
harmless results of certain colors on the animal. It is to be regretted 



7o2 



FOOD INSPECTION AND ANALYSIS. 



that physiological experiments cannot more readily be tried on human 
beings, so as to study the effects of administering to them such amounts 
as are used in food. 

More conclusive results (though still of a negative character) tending 
to establish the harmlessness of most of the coal-tar colors are given by 
Grandhomme * in statistics showing the condition of health of laborers 
in factories M^here these dyestuffs are made, in comparison with those 
engaged in other industries where poisonous materials are handled. 
From these it appears that the proportion of illness among the anilin- 
makers is remarkably small. 

In the case of coloring confectionery by the use of mineral pigments, 
a considerable amount of the coloring material must be used, forming 
without doubt a source of danger in some cases. With coal-tar dyes, on 
the contrary, the case is different. One ounce of auramine, for instance, 
has been found sufficient to give a deep- yellow color to 2,000 pounds 
of confectionery, so that almost an infinitesimal amount of the actual 
dyestuff is taken into the system. Hence it is that very little danger 
need be apprehended from the use of most coal-tar colors in food, objec- 
tionable as they certainly are as a commercial fraud. 

Injurious and Non-injurious Colors. — Various countries have enacted 
specific laws regulating the use of coloring matters in foods, especially 
England, France, Germany, Austria, and Italy. In some cases attempts 
have been made to specify harmful and harmless colors. The National 
Confectioners' Association of the United States has compiled a useful 
classified list of injurious and harmless colors,! the classification being 
based largely on the results of experiments by Weyl and Konig, as well 
as upon the Resolutions of the Association of Swiss Chemists, and on 
the French Ordinances regarding food colors. The list is as follows: 

HARMFUL MINERAL COLORS. 

Compounds 0} Copper. — Blue ashes, mountain blue, etc. 

Compounds 0} Lead. — Massicot, red lead, white lead, Cassel yellow, 
Paris yellow. Turner yellow, Naples yellow, sulphates of lead, chrome 
yellow, Cologne yellow, etc. 

Compounds oj Barium. — Ultramarine yellow, etc. 

* Weyl, Sanitary Relations of the Coal-tar Colors, pp. 28-30. 

t Colors in Confectionery. An Official Circular from the Executive Committee of th& 
National Confectioners' Association of the U. S., 1899. 



/iRTlFICI/iL hOOD COLORS. 78:3 

Compounds 0} Mercury. — Vermilion, etc. 

Compounds oj Arsenic. — Scheele's green, Schweinfurth green, etc. 
In Other Words colors in whose preparation mercury, lead, copper, 
arsenic, antimony, tin, zinc, chromium, and barium compounds are used^ 

HARMFUL ORGANIC COLORS. 

Red Colors. — Ponceau 3/?^.— Ponceau B extra, fast ponceau B, 
new led L, scarlet EC, imperial scarlet, old scarlet, Biebrich scarlet. 

Crocein Scarlet t,B. — Ponceau 4RB. 

Cochenille Red A. — Crocein scarlet 4B and G, brilliant scarlet, 
brilliant ponceau 4R, ponceau 4R, ponceau brilliant 4R, new coccin, 
scarlet. 

Crocein Scarlet 'jB. — Crocein scarlet 8B, ponceau 6RB. 

Crocein scarlet O extra. 

Sajranin. — Safranin T, safranin extra G, safranin G extra GGSS, 
safranin GOOO, safranin FF extra No. O, safranin cone, safranin AG 
extra, safranin i\GT extra, anilin pink. 

Yellow Colors. — Gum gutta. 

Picric acid. 

Martius Yellow. — Naphthylamin yellow, jaune d'or, Manchester yel- 
low, naphthalin yellow, naphthol yellow, jaune naphthol. 

Acme Yellow. — Chrysoin, chryscolin yellow T, gold yellow, resorcin 
yellow, acid yellow RS, tropaeolin O, jaune II. 

Victoria Yellow. — Victoria orange, anilin orange, dinitrocresol, saf- 
fron substitute, golden yellow. 

Orange II. — Orange No. 2, orange P, orange extra, orange A, orange 
G, acid orange, gold orange, mandarin G extra, beta-naphtholorange, 
tropaeolin OOO No. 2, mandarin, chrysaurin. 

Metanil Yellow. — Orange MN, tropaeolin G, Victoria yellow (O double 
cone), jaune G (metanil extra). 

Sudan I. — Carminaph. 

Orange IV. — Orange No. 4, orange N, orange GS, new yellow, acid 
yellow D, tropaeolin OO, fast yellow, diphenylorange, diphenylamine 
orange, jaune d'anilin, anilin yellow. 

Green Colors. — Naphthol green B. 

Blue Colors. — Methylene blue BBG. — Methylene blue BB, in powder 
extra, methylene blue DBB extra, methylene blue BB (crystalline) 
ethylene blue. 



784 FOOD INSPECTION AND ANALYSIS. 

Brown Colors. — Bismarck Brown. — Bismarck brown G, Manchester 
brown, phenylen brown, vesuvin, anilin brown, leather brown, cinnamon 
brown, canelle, English brown, gold brown. 

Vesuvin B. — Manchester brown EE, Manchester brown PS, Bis- 
marck brown, Bismarck brown T, brun Bismarck EE. 

Fast Brown G. — Acid brown. 

Chrysoidin. — Chrysoidin G, chrysoidin R, chrysoidin J, chrysoidin Y. 



HARMLESS MINERAL COLORS. 

Blue Colors. — Ultramarine blue. 

Violet Colors. — Ultramarine violet. 

Brown Colors. — Manganese brown. 

Chocolate-brown and colors of a similar nature have as their basis 
natural or precipitated oxide of iron, which in an impure condition may 
have small quantities of arsenic in its composition. It is possible with 
proper care to secure a raw material entirely free from this objectionable 
element, and no oxide of iron containing any traces of arsenic should 
be used in the preparation of color. 

Green Colors. — Ultramarine green. 

HARMLESS ORGANIC COLORS. 

Red Colors. — Cochineal carmine. 

Carthamic acid (from saffron). 

Redwood. 

Artificial alizarin and purpiirln. 

Cherry and beet juices. 

Eosin. — Eosin A, eosin G extra, eosin GGF, eosin water soluble, eosin 
3 J, eosin 4J extra, eosin extra, eosin KS ord., eosin DH, eosin JJF. 

Erythrosin. — Erythrosin D, crythrosin B, pyrosin B, primrose solu- 
ble, eosin bluish, eosin J, dianthin B. 

Rose Bengale. — Rose bengale N, Rose bengale AT, rose bengale G, 
bcngalrosa. 

Phloxin. — Phloxin TA, eosin blue, cyanosin, eosin loB. 

Bordeaux and Ponceau reds, resulting from the action of naphthol- 
sulphonic acids on diazoxylene : 

Ponceau 2R. — Ponceau G, ponceau GR. 
Ponceau R. — Brilliant ponceau G, ponceau J. 



ARTIFICIAL FOOD COLORS. 785 

Bordeaux B. — Fast red B, Bordeaux R extra. 

C eras in. — Rouge B. 

Ponceau 2G. — Brilliant ponceau GG, ponceau JJ. 

Fuchsin 5.— Acid magenta, rubin S, fuchsin acide (free from arsenic). 

Archil Substitute. — Naphthion red. 

Orange I. — Orange No. i, naphtholorange, alpha-naphtholorange, 
tropaeolin OOO No. i. 

Congo red. 

Azoruhin S. — Azorubin, azorubin A, azoacidrubin, fast red C, car- 
moisin, brilliant carmoisin O, rouge rubin A. 

Fast Red D. — Fast red EB, fast red NS, amaranth, azoacidrubin 2B, 
Bordeaux DH, Bordeaux S, naphthol red S, naphthol red O, Victoria 
ruby, wool red (extra), (jenanthinin. 

Fast Red. — Fast red E, fast red S, acid carmoisin S. 

Ponceau 4GB. — Crocein orange, brilliant orange G, orange GRX, 
pyrotin orange, orange ENL. 

Fuchsin. 

Metanitrazoiin. 

Yellow and Orange Colors. — Annatto. 

Saffron. 

Safjlower. 

Turmeric. 

Naphthol Yellow S. — Citronin A, sulphur yellow S, jaune acide, 
jaune acide C, anilin yellow, succinine, saffron-yellow, solid yellow, 
acid yellow S. 

Brilliant Yellow. — (Sch.) 

Ponceau 4GB. — Crocein orange, brilliant orange G, orange GRX, 
pyrotin orange, orange ENL. 

Fast Yellow. — Fast yellow G, fast yellow (greenish), fast yellow S, 
acid yellow, new yellow L. 

Fast Yellow R. — Fast yellow, yellow W. 

Azarin S. 

Orange /.—Orange No. i, naphtholorange, alpha-naphtholorangc, 
tropteolin OOO No. i. 

Orange. — Orange GT, orange RN, brilliant orange O, orange N. 

Mixtures of harmless red and yellow colors. 

Green Colors. — Spinach green. 

Chinese green. 

Malachite Green. — Malachite green B, benzaldehyde green, new Vic- 



786 FOOD INSPECTION AND ANALYSIS. 

toria green, new green, solid green crystals, solid green O, diamond green, 
bitter amond oil green, fast green. 

Dinitrosoresorcin. — Solid green O in paste, dark green, chlorine green, 
Russia green, Alsace green, fast green, resorcinol green. 

Mixtures of harmless blue and yellow colors. 

Blue Colors. — Indigo. 

Lilmiis. 

Archil blue. 

Gentian Blue 6B. — Spirit blue, spirit blue FCS, opal blue, blue 
lumiere, Hessian blue, light blue. 

Couplers Blue. — Fast blue R and B, solid blue RR and B, indigin DF, 
indulin (soluble in alcohol) , indophenin extra, blue CB (soluble in alcohol), 
nigrosin (soluble in alcohol), noir CNN. 

In General such blues as are derived from triphenylrosanilin or from 
diphenylamin. 

Violet Colors. — Paris Violet. — Methyl violet B and 2B, methyl 
violet V3, pyoktanin cceruleum, malbery blue. 

Wool black. 

Naphthol black P. 

Azoblue. 

Mauvein. — Rosolan, violet paste, chrome violet, anilin violet, anilin 
purple, Perkins violet, indisin, phenamin, purpurin, tyralin, tyrian purple, 
lydin. 

Brown Colors. — Caramel. 

Licorice. 

Chrysamin R. 

Use of Colors in Confectionery. — Regarding the choice of colors for 
use in confectioner)^ and precautions to be observed in their use, the 
Confectioners' Association has offered the following considerations: 

First. That coal-tar colors are specially adapted to the wants of 
confectioners on account of their brilliancy, permanency, and high color- 
ing power, by reason of w^hich last-named quality only infinitesimal 
amounts of color need be or can be used to give the desired effects. 

Second. That there is no evidence to show that any poisonous or 
hurtful colorings have in recent years been found in confectionery. 
Reports of deaths from poisoned candy are only too frequently made, 
but no autopsy has ever been published confirming them. 

Third. That while the exceedingly small proportions of color used 
in confectioner}' constitute a practical safeguard to the public health, con- 



ARTIFICIAL FOOD COLORS. 787 

fectioners are in duty bound to provide against all possible contingencies 
of harm, by using the utmost care in obtaining absolutely non-poisonous 
colors, buying only from color-dealers of established reputation and 
unquestioned responsibility, whose colors are tested at frequent intervals, 
and are vouched for by competent chemists. 

Confectioners should require that a guarantee be put upon each 
package of color, stating not only that the contents are non-poisonous, 
but also that they will not in any way interfere with digestion or injure, 
health. 

Fourth. Any illegitimate use of coloring matter in confectionery as 
a substitute for chocolate or any other material or ingredient, or for the 
purpose of adding bulk or increasing the weight of the confectionery 
in which it is incorporated, should not be permitted or countenanced. 
Both the letter and the spirit of these laws should clearly prevent the 
illegitimate use of coal-tar colors or of earth colors, such, for example, as 
chocolate-brown, coconole brown, or chocolatina. 

Fifth. That color-dealers furnishing colors to confectioners should 
publish printed lists of their colors under the various names and titles 
by which they are known and offered for sale, accompanying such lists 
with ample certifications by competent chemists to their purity and suit- 
ableness for coloring confectionery and other articles of food. They 
should also attach to each package or other container of color a guar- 
antee that it does not contain anything injurious to health. 

VEGETABLE COLORS. 

These with a few mineral pigments and cochineal were formerly 
almost exclusively used for coloring food products, and are still used 
to some extent. 

Most of the vegetable colors, according to L. Robin,* react with 
ammonia to form a coloration, usually passing from violet to blue, then 
to a brownish green, when the ammonia is added little by little in excess 
to the color in solution. If by the addition of ammonia to a solution 
of an unknown color the green coloration does not result, the presence 
may be suspected of orchil or cudbear, logwood, cochineal, or a coal-tar 
dye. 

The following vegetable colors are occasionally found in food, with 
some of the reactions in aqueous solution, as given by Robin: 

* Girard et Dupre, Analyse des Matieres Alimentaires, p. 579. 



jSS 



FOOD INSPECTION AND ANALYSIS. 
RED COLORS. 



Nature of Color. 



Ammonia. 



Alum and Sodium Carbonate 
20% Solution. 



Lake. 



Filtrate from 



Mixture of 
Aluminum 
Acetate and 

Sodium 
Carbonate. 



Bilberry (whor 
tlcberry) 

Beet 

Black currant. . . 
Logwood 

Brazil wood 

Raspberry 

Currant 

Blackberry 

Phytolacca 

Elderberry 



Dull greenish 



Muddy yellow, 
brown, or rose- 
rcd 
Deep green 
Red tinged with 
violet 

Currant-red 
Bluish green 

Yellow-brown to 
greenish 
Yellowish green 

Lilac 



Light green 



Greenish blue, 
rose-colored on 
edges 

Dull green or rose 



Greenish blue 
Blue tinged with 
violet 

Rose 
Ro.se tinged 

Gray to lilac 

White or rose vio- 
let 

Violet 



Blue tinged witli 
violet 



Bottle-green 



Rose tinged 
Bluish green 

Dull maroon to 
bottle-green 
Bluish 



Bluish violet 



Garnet 



Violet-blue 
Tinged with violet 

Lilac to wine color 
Lilac tinged with 
violet 
Red-maroon 

Dull violet 

Clear violet, pass- 
ing to yellow 
with ammonia 

Violet, ([uickly 
jiassing to blue 
with acetate of 
copper 



YELLOW COLORS. 



Nature of Color. 


Ammonia. 


Hydrochloric Acid. 


Alum and Carbonate 

of vSoda 20% 

Solution. 

Lake. 


Persian berries 

Old fustic 


Yellow-red 

Very bright yellow 
Becomes clearer 

Yellowish red 
Brown-red 


Preci])itate yellow- 
l)rown 
Yellow-orange 
Bright yellow pre- 
cipitate 
Becomes yellower 
Crimson precipitate 


Orange 

Orange 

Yellow-red tending to 

green 

Bright yellow 

Bright yellow 


Quercitron bark 

Young fustic 

Turmeric 





Additional yellow vegetable colors sometimes used in foods are the 
following, taken from a table of Leed's,* showing reactions given by 
treating a few drops of an alcoholic solution of the color with an equal 
volume of the reagent. 

Most of these vegetable colors do not directly dye wool or silk a fast 
color, but as a rule require the use of a mordant. Many of these colors 
may be fixed on cotton (previously mordanted by boiling in a solution 

* Analyst, 12, 150. 



ARTIFICML FOOD COLORS. 
REACTIONS OF COLORING MATTERS. 



789 



Coloring 


Concentrated 


Concentrated 


H2SO4 + HNO3. 


Concentrated 


Matter. 


H2SO4. 


HNO3. 




HCl. 


Annatto. . . . 


Indigo-blue, chang- 


Blue, becoming 


Same 


No change, or only 




ing to violet 


colorless on 
standing 




slight dirty yel- 
low and brown 


Turmeric. . . 


Pure violet 


\'iolet 


Violet 


Violet, changing to 
original color on 
evaporation oi 
HCl 


Saffron 


Violet to cobalt 


Light blue, chang- 


Same 


Yellow, changing 




blue, changing to 


ing to light red- 




to dirty yellow 




reddish brown 


dish brown 






Carrot 


Umber brown 


Decolorized 


Same with NOj 
fumes and odor 
of burnt sugar 


No change 


Marigold. . . 


Dark olive-green, 


Blue, changing in- 


Green 


Green to yellowish 




permanent 


stantly to dirty 
yellow-green 




green 


Safflower. . . 


Light brown 


Partially decolor- 
ized 


Decolorized 


No change 



of aluminum acetate or potassium bichromate) by boiling the mordanted 
fibers in a bath of the colored solution, rendered acid by acetic acid. The 
dyed fibers arc then examined by reagents, as in tables given on pages 
804-11. 

Special Tests for Vegetable Colors.— Orchil and Cudbear, both 
derived from lichens, dye wool red in acid bath. The colored fiber, 
in the case of cudbear, is turned blue by treatment with ammonia. For 
reactions of orchil on the fiber see table, page 807. Robin's test for orchil 
in aqueous solution consists in shaking it with ether, which, if orchil is 
present, is colored yellow. On treatment of the ether with ammonia, 
the yellow color is changed to blue, and, by adding acetic acid, goes over 
to a reddish violet. 

Logwood, according to Robin, in aqueous solution colors ether yellow^ 
and on treating the ether with ammonia the color becomes red or faintly 
violet. Potassium bichromate gives a violet coloration, mingled with 
greenish yellow. If cotton is first mordanted by boiling with aluminum 
acetate, it is dyed violet when boiled in a solution of logwood. 

Turmeric is best extracted from a dry residue with alcohol, which it 
colors yellow. The color is transferred to a piece of filter-paper by soak- 
ing the paper in the alcoholic tincture, the paper is dried and dipped 
in a dilute solution of boric acid or borax slightly acidulated with hydro- 
chloric acid. On again drying the paper, it will be of a cherry-red color 
if turmeric is present, and when touched with a drop of dilute alkali wull 
turn dark olive. 



790 FOOD INSPECTION AND ANALYSIS. 

Caramel. — Care should be taken in testing for caramel not to subject 
the sample to long-continued heating, even on the water-bath. Indeed 
caramel is sometimes developed spontaneously in saccharine food prod- 
ucts during their process of manufacture vv^hen heat is used, by the charring 
of the sugar. If solutions are to be concentrated or brought to dryness 
before testing for caramel, this should be done in a vacuum desiccator 
over sulphuric acid, or at a temperature not exceeding 70°. For detection 
of caramel in milk, vinegar, and liquors, special tests are given elsewhere. 

Fradiss Test* — The dried residue of the sample to be tested is 
extracted wiih warm, pure methyl alcohol, which, if caramel be present, 
is colored brown. Filter, and to the filtrate add amyl alcohol or chloro- 
form. In presence of caramel, a brown flocculent precipitate is formed, 
which slowly settles to the bottom of the tube. 

Indigo in aqueous solution turns green with ammonia. On boiling, 
the solution becomes bright blue. Indigo in neutral or acid solution 
dyes wool or silk. 

ANIMAL COLORS. 

Cochineal. — This dyestuff is used in ketchups, cordials, confections, 
and other food products. Robin's test for cochineal is as follows: The 
aqueous solution is acidulated with hydrochloric acid, and shaken out 
in a separatory funnel with amyl alcohol. Cochineal imparts to this 
solvent a yellowish color, the depth depending on the amount present. 
The separated amyl alcohol is washed with water till neutral, and 
divided into two portions. To one of these a little water is added, 
and then drop by drop a solution of uranium acetate, shaking each time 
a drop is added. In presence of cochineal the water is colored a very 
characteristic emerald-green color. To the other portion ammonia is 
added. If cochineal has been used, a violet coloration is produced. 

MINERAL PIGMENTS. 

Evidence of the presence of these pigments is usually best looked for 
in the ash of the suspected sample. In some cases the color may be 
extracted from the dried residue by water, alkali, or alcohol. 

Prussian Blue. — This pigment is insoluble in water. It is decom- 
posed and decolorized by treatment with potassium hydroxide. If the 

* Oestr. ungar. Zeits. Zucker. Ind., 1899, 28, 229-231; Abs. Zeits. f. Unters. Nahr. u. 
Genuss., 2, 1899, P' ^8'- 



ARTIFICIAL FOOD COLORS. 79I 

filtered alkaline solution of the coloring matter be treated with hydro- 
chloric acid and ferric chloride, a precipitate of the original Prussian 
blue will be produced. For reactions on the fiber see table, page 810. 

Ultramarine Blue is decolorized by hydrochloric acid with evolution 
of hydrogen sul[)hide, which blackens filter-paper moistened with lead 
acetate. For the recognition of ultramarine in sugar see page 613. For 
its detection on the fiber see table, page 811. 

Chromate of Lead has never been used to any extent in food products 
with the exception of confectionary. For its detection, see page 647. 

COAL-TAR COLORS. 

So many of the coal-tar dyes are adapted for use in food that it would 
be impossible to even name them all, especially in view of the fact that 
new colors are from time to time being added to the list. No attempt 
will be made in the present work to give the nature and composition of 
the dyes named, as such descriptions would lead beyond its scope. For 
detailed information along this line the reader is directed to the references 
on page 813, and especially to the works of Schultz and Julius, Benedict 
and Knecht, Weyl, etc. 

About 2000 separate coal-tar dyes are at present on the marke!;. 
Various classifications of these colors are attempted, based on (i), their 
origin, as anilin dyes, naphthalin dyes, anthracene dyes, etc.; (2), their 
chemical composition, as nitro, nitroso, azo, diazo, and other compounds; 
(3), their solubility in water and other solvents; and (4), their mode 
of application to the fiber, as basic dyes, acid dyes, direct cotton dyes, mor- 
dant dyes, etc. 

These dyes are sold in the form of powder, and are readily made 
into solutions for food colors in the case of the water-soluble varieties, 
and into pastes in the case of the insoluble forms. Most of the coal-tar 
colors employed in foods are naturally of the soluble variety, especially 
such as are found in jellies, jams, fruit products, canned foods, ketchups, 
beverages, and milk. Pastes made from insoluble dyes are adapted 
mainly for exterior coatings of hard substances such as candies. Colors 
in the dry form are to be looked for in such spices as cayenne, mustard, 
and mace, but a commoner method of coloring these spices high in oil 
is to mix with them a solution of the color in oil (usually cottonseed). 
Oil solutions of coal-tar dyes are also employed for coloring butter and 
oleomargarine. ■...■■.< 

The chief concern of the food analyst, as regards artificial color is 



792 FOOD INSPECTION /1ND ANALYSIS. 

its recognition in food products. Coal-tar dyes may usually be iden- 
tified as such, but it is not always possible to name the particular 
individual dye or combination of dyes employed, even though the class 
to which they belong may be determined. One reason for this is that 
not infrequently mixtures of two or more colors are employed. 

Coal-tar Colors Allowed under the Federal Law. — The use of 
any dye, harmless or otherwise, to color food in a manner whereby 
damage or inferiority is concealed is in violation of Sec. 7 of the Food 
and Drugs Act of June 30, 1906. The addition of all mineral or metallic 
dyes, and of all coal-tar dyes, other than those specially provided for, 
is also prohibited. Pending further investigation the following coal-tar 
colors are permitted in foods, provided they are certified to be true to 
name and to be free from mineral and metallic poisons, harmful organic 
constituents, and contaminations due to improper or incomplete manu- 
facture : * 

Red Shades. — 107. Amaranth [M.] [C.]. Synonyms: Fast red D. [B.] 
Bordeaux S. [A.], azoacidrubine 2B. [D.], fast red EB. [B.]. 

56. Ponceau 3R. [yl.] [5.] [M.]. Synonyms: Ponceau 4R. [.4.], 
cumidin red, cumidin ponceau. 

517. Erythrosin [B.]{M.][B.S.S.]. Synonyms: Erythrosin D. [C], 
erythrosin B. [A.], pyrosin B. [Mo.], iodeosin B., eosin bluish, eosin J. [B.]. 

Orange Shade. — 85. Orange I. Synonyms: Alphanaphthol orange^ 
naphthol orange {A.], tropaeolin 000 No. i, orange B. [L.]. 

Yellow Shade. — 4. Naphthol yellow. S. [B.]. Synonyms: Naphthol 
yellow, acid yellow S., citronin A. [L.]. 

Green Shade. — 435. Light green S. F. yellowish [B.]. Synonyms: 
Acid green [By.] [M.] [T.M.] [O.], acid green extra cone. [C.]. 

Blue Shade. — 692. Indigo disulphoacid. Synonyms: Indigo car- 
mine, indigo extract, indigotine {B.], sulphonated indigo. 

None of these seven colors is patented, hence their manufacture is 
not likely to become a monopoly. They may be used in combinations, 
thus securing any desired shade. For example, violet may be obtained 
by mixing indigo disulphoacid and one of the red colors, a blue-green by 
mixing indigo-disulphoacid with naphthol yellow S. or light-green S.F. 
and so on. 



*The numbers preceding the dyes are those given in Green: A Systematic Survey of 
the Organic Colouring Matters founded on the German of Schultz and Julius, London*. 
1904; the letters in brackets represent the manufacturers who originated the names. 



ARTIFICIAL FOOD COLORS. 79 J 

Detection of Coal-tar Colors in Foods. — ^There are various 
methods for the separation of coloring matters from food products, and 
these may be divided into three general classes: First, dying silk or wool 
with the color by boiling the fiber in a solution of the sample to be 
examined; second, extracting the color from a solution of the sample 
by the use of an immiscible solvent; and third, extracting the color from 
the dried residue of the sample by means of a suitable solvent. Of these 
the method of dying wool lends itself most readily to the analyst's use, 
by reason of its simplicity, and from the fact that almost without excep- 
tion coal-tar dyes adaptable for food colors are substantive dyes, being 
readily taken up by wool. 

Basic and Acid Dyes. — The soluble coal-tar dyes are either basic 
or acid. Basic dyes are precipitated from their aqueous solution by 
tannin. Acid dyes are not so precipitated. Theoretically, all the basic 
colors are taken up by wool from a faintly alkaline or neutral bath, while 
the acid colors are left in solution. Thus if a dilute solution of the color 
be made faintly alkaline with ammonia and boiled with the wool, only 
basic colors will be taken up. If both acid and basic dyes arc present 
in the same solution, the basic color should first be exhausted by the 
use of fresh pieces of wool in the ammoniacal solution, till they no longer 
take out color, after which the solution should be made slightly acid 
with hydrochloric acid and again boiled with wool, which under these 
conditions takes out any acid colors. Comparatively few basic colors 
are employed in foods. Basic colors can be removed from the fiber 
by boiling with 5% acetic acid. Acid colors are removed therefrom by 
boiling with 5% ammonia. Having dissolved the dye from the fiber 
by the appropriate solvent as above, the decolorized fiber may be removed, 
and the solution evaporated to dryness on the water-bath. The residue 
consists chiefly of the dyestuff, and may be put through various reactions 
for identification according to Rota's scheme, page 797. 

Methods of Dyeing Wool from Food Products.— The wool employed 
should be white worsted, or strips of white cloth, such as nun's veiling 
or albatross cloth. Care should be taken that the color is pure white 
and not the more common cream white. The woolen material should 
be freed from grease by boiling first in very dilute soda solution and 
finally in water. Strips of the woolen cloth, or pieces of the worsted thus 
previously cleansed, are boiled in diluted filtered solutions of jams, jellies, 
ketchup, fruit and vegetable products, and similar food preparations, or 



794 FOOD INSPECTION AND ANALYSIS. 

in solutions of candy colors, or in wines, the clear solution of the sample 
to be tested being slightly acidified with hydrochloric acid. 

Arata * recommends boiling the wool in a dilute solution of the food 
material to which potassium bisulphate has been added, using lo cc. 
■of a io% solution of the bisulphate to loo cc. of the solution to be tested. 
If the color solution is neutral, the wool should first be boiled in this 
before acidifying, to separate out any basic dyes. The dyed wool, after 
removal from the solution, is boiled first in water, and afterwards prefer- 
ably in an alkali-free soap solution. It is then washed and dried. The 
•dried fiber may then be subjected to the various reactions given in the 
table, pp. 804-811; for recognition of the dye, this method of identifying 
colors by means of reactions on the dyed fiber being one of the most con- 
venient. 

Some of the vegetable d3'es (including lichen colors) , also cochineal, dye 
v^rool directly, and these may be identified by reactions given in the table 
with the coal-tar dyes. Other vegetable colors, and the natural colors 
of fruits nearly always give a slight dull coloration or stain to the wool, 
but this is not, as a rule, to be mistaken for the vivid hues of the coal- 
tar dyes. Moreover most of the vegetable colors on the fiber turn green 
when treated with ammonia. Care should be taken to thoroughly wash 
the wool after the dyeing, so that colored particles simply held thereon 
mechanically may be removed. 

Sostegni and Carpeniieri'\ recommend a method of double dyeing, 
applicable when acid dyes are employed. The method consists in 
first boiling the wool in a dilute acid solution of the food sample as 
above described, after which the fiber is removed and boiled, first in 
very dilute hydrochloric acid solution, and then in water, till free from 
acid. The color is then dissolved from the fiber by boiling the latter 
in a weak ammoniacal solution, some of the colors being more readily 
dissolved than others. The fiber is then removed from the solution, 
the latter is acidified with hydrochloric acid, and the color fixed on a 
fresh piece of wool by boihng therein. The second dyeing fixes coal- 
tar and lichen colors on the fiber, but fruit colors and most others of 
vegetable origin remain in solution after this treatment. Any color left 
on the first fiber, after treatment with ammonia, is probably due to the 



* Ztsch. anal. Chem., 28 (1889), 639. 
t Ibid., 35 (1896), 397. 



/tRTIFCIAL FOOD COLORS. 795 

natural vegetable color of the sample, and is usually no more than a 
dull stain. 

Vegetable Colors on Wool. — In case no color is directly fixed on the 
fiber by boiling wool in a solution of the sample, either neutral or acid, 
absence of coal-tar colors may be assumed. In this case it is sometimes 
advisable to boil strips of previously mordanted white cotton in an acid 
solution of the sample, to remove certain vegetable colors for purposes 
of testing on the fiber. The cotton is mordanted by boiling in a dilute 
(5%) solution of potassium bichromate. 

Extraction of Colors from their Solution by Immiscible Solvents.— 
Methods based on this principle are in use in the municipal laboratory 
at Paris.* Sangle-Ferriere uses the following method: 50 cc. of the 
wine or solution to be tested for color are rendered slightly alkaline by 
ammonia, and cautiously shaken with about 15 cc. of amyl alcohol. If 
acid dyes art; present, they will be dissolved, and will impart to the amyl 
alcohol a distinct color.f Basic dyes also are dissolved, but when they 
are present the amyl alcohol solution is colorless. Remove the amyl 
alcohol by means of a separatory funnel, wash with water, and finally, 
if the alcohol is colored, dilute with about an equal volume of distilled 
water and evaporate on the water-bath with a piece of white wool. The 
wool should be kept in the solution till the odor of the amyl alcohol has 
disappeared, and, if not then colored, for a short time longer, as with 
some colors the wool will dye more readily in the aqueous solution than 
in the amyl alcohol. Remove the wool, and evaporate the solution to 
dryness. Test for color in the dried residue, and on the fiber also. 

Orchil, like the acid colors, is extract^'d by, and imparts a coloration 
to the amyl alcohol under the above conditions, the color being a light 
violet. 

If the amyl alcohol extract after separation, washing, and filtering 
is colorless, acidify with acetic acid; if a basic color is present, it will 
be indicated by a coloration at this stage; if there is no coloration on 
the addition of acetic acid, no basic color is present excepting fuchsin, 
which is separately tested for. In case a basic dye is indicated, add dis- 
tilled water and evaporate with wool as before. Test the dried residue 
with pure concentrated sulphuric acid. 

* Girard et Dupre, Analyse des Matiers Alimentaires, pp. 167, 581. 

t Acid fuchsin forms an exception to this rule by dissolving colorless Uke basic dyes. 
A special te«t is, however, given for it, p. 797. 



\ 



796 FOOD INSPECTION AND ANALYSIS. 

Fuchsin is indicated by a yellow-brown color with sulphuric acid, 
which by dilution with water becomes rose; sajranin, by a green color 
becoming first blue, then red, when diluted with water, and magdala 
red by a dark blue color, turning red on the addition of water. 

Basic colors are also extracted readily, according to Robin, by making 
the solution to be tested alkaline with sodium hydroxide, and shaking 
with acetic ether. The solvent is removed, washed, and evaporated 
with wool (on which the tests are to be made), or the evaporation is 
carried to dryness and the tests made on the residue. 

Many coal-tar colors are extracted by amyl alcohol in acid solution, 
but some of the natural fruit colors are also dissolved under these con- 
ditions. The coal-tar dyes thus dissolved will, however, dye wool and 
the fruit colors will not. Fruit colors are not extracted from acid or 
alkaline solution by ether, nor from alkaline solution by amyl alcohol. 

Robin's method for ascertaining whether acid color^ are present 
consists in adding to the liquid to be tested an excess of calcined magnesia, 
and a little 20% mercuric acetate solution, the mixture being boiled and 
filtered. If the filtrate is colored, or if by the addition of acetic acid 
to the colorless filtrate a color is developed, a coal-tar dye is indicated. 

Separation of Acid and Basic Colors with Ether.* — Acid and basic 
colors may be separated from their dilute aqueous solution, according 
to Rota, by means of ether as follows: To 100 cc. of the solution add 
I cc. of 20% potassium hydroxide and shake in a separatory funnel with 
several portions of ether. Basic dyes are dissolved by 'the ether, leaving 
behind as a rule the acid colors. f Wash the ether extract with faintly 
alkaline water, and shake out with 5% acetic acid. Some colors remain 
in the ether, others are dissolved in the acid. Separate the two solvents, 
and evaporate each to dryness on the water-bath. 

The acid colors left in the slightly alkaline, aqueous solution after 
removal of the basic colors by ether as above, may, if desired, be separated 
into several groups by successive extraction, as follows: first slightly 
acidulate with acetic acid and extract with ether, then acidify with hydro- 
chloric acid and again extract, and finally examine the residual solution 
for colors that are insoluble in ether. Thus erythrosin and eosin are 
soluble in ether when shaken with their aciueous solution made acid with 
hydrochloric acid, while acid fuchsin is insoluble. 

* Analyst, 24, p. 45. 

t A few acid dyes are exceptional in being soluble in ether with alkali, as for example, 
quinolin yellow and the sudans. 



I 



ARTIFICIAL FOOD COLORS. 797 

Separation of Colors from Dried Food Residues by Solvents. — This 

method is rarely employed, excepting in the case of colors insoluble in 
water, but soluble in e.her or alcohol. The dried pulp of canned veget- 
ables, ketchups, etc., may be acidified wi.h hydrochloric acid, and the 
color extracted therefrom directly wi.h alcohol. In this case however, 
there is no obvious advantage over the previous methods of dyeing the 
fiber directly in the acid solution of the sample. 

Girard's Tests for Acid Fuchsin.* — Add 2 cc. of 5% potassium 
hydroxide to 10 cc. of the wine or other solution to be tested, or enough 
of the alkali to neutralize the acid. Then add 4 cc. of 10% acetate of 
mercury and filter. The filtrate should be alkaline and colorless. If 
the solution remains uncolored after acidifying with dilute sulphuric 
acid, no acid fuchsin is present. If, however, there is produced a red 
to violet coloration, and no other coal-tar colors have been found by the 
amyl alcohol extraction, the presence of acid fuchsin is shown. 

Bellier's Test for Acid Fuchsin. — Presence of acid fuchsin is indicated 
by adding to 20 cc. of wine or other solution to be tested about 4 grams 
of freshly precipitated yellow oxide of mercury, boiling and filtering. 
The filtrate, if acid fuchsin is present, is colored red, tinged with 
violet. 

According to Blarez, all red coal-tar colors, with the exception of 
acid fuchsin, and all red vegetable colors are completely decolorized 
by acidulating their aqueous solution with tartaric acid, and digesting 
with dioxide of lead.f 

Schemes for Identification. — These serve for identifying unknown 
colors by their characteristic reactions, first grouping them into classes, 
and finally ascertaining the particular color itself. Of these may be 
mentioned the tabular schemes of Witt,t Weingartner,§ Green, |[ Mar- 
tinon,^ and Rota.** 

Rota's Scheme is one of the latest, and on some accounts the best, 
being based on the relation between the color and the composition of 



* Analyse der Substances Alimentaires, p. 169. 

t Allen, Commercial Org. Analysis, vol. Ill, p. 283. 

X Zeits. anal. Chem., 1887, 26, p. 100; Analyst, 11, p. iii. 

§ Jour. Soc. Dyers, etc., Ill, p. 67. 

II Jour. Soc. Chem. Ind., 12, No. i. 

Tf Jour. Soc. Dyers, 3, p. 124. 

** Chem. Zeit., 1898, pp. 437-442; Anal., 24, p. 41. 






FOOD INSPECTION AND ANALYSIS. 



the dyes. The colors are divided into two main groups, according to 
whether or not they are reducible by stannous chloride. These two. 
groups are each further subdivided into two classes, the reducible colors 
being classed according to wheher the color remains unchanged, or is 
restored by treatment with ferric chloride, and the non-reducible colors 
according to their action with potassium hydroxide. 

The tests are carried out on a dilute aqueous or alcoholic solution 
of the coloring matter, the strength being about i in 10,000. Treat 
about 5 cc. of this solution with 4 or 5 drops of concentrated hydrochloric 
acid and about as much stannous chloride in a test-tube, shake the mix- 
ture, and heat if necessary to boihng. Wi:h some colors the process of 
decolorization is a slow one, especially if the solution is too concentrated, 
and it is well to repeat the experiment, if in doubt, diluting the original 
sample still further with water. Tin in solution in concentrated hydro- 
chloric acid may be employed instead of stannous chloride, if desired. 

Here, as in all cases of color testing, it is well to make comparative 
tests with known colors. 

CLASSIFICATION OF ORGANIC COLORING MATTERS. 
[A portion of the aqueous or alcotiolic solution is treated with HCl and SnClj.] 



Complete decolorization. Reducible coloring 
matters. Colorless solution is treated with 
Fe .Clj, or shaken with exposure to air. 



The color changed no further than with HCI 
alone. Nonreducible colors. A part of 
original solution is mixed with 20% KOH 
and warmed. 



The liquid remains 
unchanged. Color- 
ing matters not re- 
oxidizable. 



Class I. 

Nitro, nitroso, and azo 
colors, including 
oxyazo and hydrazo 
colors. 

Picric acid, naphthol 
yellow, ponceau, 
Bordeaux, and 
Congo red. 



The original color re- 
stored. Reoxidiz- 
able coloring mat- 
ters. 



Class II. 

Indogenide and imido- 
quinone coloring 
matters, methylene 
blue, safranin, in- 
digo carmine. 



Decolorization, or a 
precipitate. Imido- 
carbo-fiuinone color- 
ing matters. 



Class III. 

Amido-derivatives of 
di and triphenyl 
methane, a u r a - 
mins, acridins, 
quinolins, and 
color derivatives of 
thio benzenil. 

Fuchsin, rosanilin, 
auramin. 



No precipitation. 
Liquid becomes 
more colored. Oxy- 
carbo-quinone col- 
oring matters. 

Class IV. 

Nonamide diphenyl 
methane, oxv-ke- 
tonc, and most of 
natural organic col- 
oring matters. 

Eosins, aurin, aliz- 
arin. 



ARTIFICIAL FOOD COLORS. 



199 



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FOOD INSPECTION AND ANALYSIS 



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ARIIFICIAL FOOD COLORS. 



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8o2 



FOOD INSPECTION AND /iNA LYSIS. 



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ARTIFICML FOOD COLORS. 803 

Direct Identification of Colors. — In identifying the colors commonlj 
used in food, it is rarely necessary to carry out such involved processe? 
of analyses as are rendered necessary by Rota's scheme. It is frequently 
possible to ascertain the color or group of colors present by making direct 
tests with various reagents, cither on the dyed fiber as described on p. 812, 
or on the dry coloring matter, or in a solution containing it. 

Many tables for this purpose are prepared, but they are never com- 
plete by reason of the many new dyestuffs constantly introduced. Such 
tables are to be found in Allen's "Commercial Organic Analysis," and 
in Schiiltz and Juhus's "Systematic Survey of the Coal Tar Colors." 
While it is true that the limitation of the dyes suitable for purposes of 
food coloring imposes a somewhat lighter task on the food analyst than 
that of the chemist who has to deal with all varieties of commercial colors, 
yet it is obviously impossible to make a complete list covering even the 
restricted field of food colors. Doubtless there are colors long well 
kn»)wn that would serve admirably for this purpose, but have never yet 
been tried. 

Mainly from such sources as the above comprehensive tables of colors 

and iheir reactions, the writer has compiled the table on pp. 804-811, 

taking as a basis the scheme of Allen.* This table includes over fifty 

selected coloring matters, which are adapted for, and have been 

found in, foods by various analysts, as listed in state and government 

reports, as well as in laws of various countries dealing with food 

colors. This table will at least contain the colors most commonly met 

with, and will nearly always serve, if not to identify the exact dye, to 

aid in classifying it. In case the analyst wishes to identify the color, 

he should l)e provided, for standards, with as complete a collection of 

known purity dyestuffs as possible covering the colors he is likely to 

meet with in foods, and should make comparative tests, if the slightest 

doubt exists. If the unknown color is apparently not found in the following 

i table, and the more exhaustive tables are unavailable, it is still possible 

' to locate the dye, by making similar tests on other standard colors sug- 

' gested by the behavior of the unknown color, and carefully comparing 

, them. 

j Most difficulty is encountered when the coloring matters are mixtures 

! instead of simple dyes. In this case it may be necessary to resort to frac- 
I tional extraction by ether, as suggested by Rota (p. 796), in order to. 
f separate the colors. 

* Commercial Organic Analysis, Vol. Ill, pt. i, 3d ed., p. 530 et seq. 



8o4 



FOOD INSPECTION AND /IN A LYSIS. 



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c 


- 5 

5fc 


E 

re 


>• 

c 


1 


' T 

'Z 


" ^ 2 - 
d-r Ci. 5 


'tr 

c 


0: 
b 
C 


■>-' nq P-i <r 

Ih >- 

- 2 d [ 
.d u Ld c 


re 


PC 


p: 
a. 


PC 

re 

_i 

c 
p: 




C 

1- 

re 


c 

a 
d 
< 








^ 


< 




c/- 


Pi 


1 


C. 


p. 


Pi 


'w 


p: 


tt 


w 


< 


PS 


c^ 




uc 


\^ 




\i. 




Pt, 


tt. 







ARTIFICIAL FOOD COLORS. 



80 ! 



en 

CO 



p JJ 

Hi ti 






p m -O 






Pico -5 c .5 



.N ^ 



• - — •;: • - •:-, M 



IZi ^^^ ^ 



A^ 



Pi PL, 



^ — rt o 

fe>^ cm 



.ES .2 ■£ N aj 5lC_N _N 



Q rt _bC bX) bc bi 

■5^ H^i ;:; ;j;3 





3 


2 


IL/ Oj 


^ 


3 


^^ 




bc bc 




c 



^< 



a:: 
cog 



>^ >^ 







g 


d c; 




V 








is ^ 




3 


-> ^ 


^ 


•r^ 


ue to bro 

ue to bro 

Black 


c 


Yellow 

ellow, b] 

rim 

Yellow 


§1 


"0 


0^ 

03 


2 












> 






>i 


pqm 





& ^ 



,^ Jx pn 









PhIIh 



;zi^ 



Ph Ph h. Ph 



O Q 



>^ 






bC o 

o 



^^^ 






Ph 



uu 



cq M 



.5 o 



£P 



f^ 



Ph 



^ o c; 0; oj 



O PPH » P5g 



2 .S 



5 ^ 






rt 


^ 


U^ 








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fi 


i- 






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<■ 



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UPL, 



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O O 

■C c c 



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rt o 3 
c o u C 



o 



P5 



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8o6 



FOOD INSPECTION AND ANALYSIS. 



o >- 



^ S 

1^ t; 
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M .2 .2 



ii a. 



U 





r! 


-o 


c 


is 




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o 


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n 


m 


■u 






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m 



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w 

H 

O 

{/} 

P4 

o 
o 

U 

o 

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2 

h 
< 
y 

I— ( 

h 

w 
P 



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p^ 



c/3 cj 



1-. aj O 



Cii P^ f? 



QQ 



^ > 



o l* 



p p 



<< 



< 



< < 



Ph 



HJ OJ P 



>^o 



o o -Y 



O O 



OJ 


4i «5 


o S ^ ^ 


cin 


^ d 


O O O m 


cS 


^ ^ 


^ ^ a. :3 ^ 


2 

"0 




-d-d T3 >-. e u 








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PPf=^ 



1^ ^ 



& So 



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5 '^ 

I ^ ^ 



>-i! >>'d 2-d §, 
oj ai OJ ^ -9 & •> 
C f^C CL^ CXO 

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O 



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q'-S 



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o 

< 

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< o 

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t/30 



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=" -n ^ •? :S t; :S T3 "3 
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>>.^ M o 5P o Sf ■£ p 
Jg< gH gH 2^H 
(iH O O O 



ARTIFICIAL FOOD COLORS. 



807 



>■< 



Ph ^ 



S S i^ 
.2 .2 ■" 

c o ^ 






-S U ^ 



>^-^ 



C o o 
.2 'S ^ 



Ph 



^ 


c 


^ 


OJ 


N 


-C 


_o 







> 









U 




^ 






Q 












>. >H 






oj O Ih 



<a o 
Cj3 



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U 



PL|> 



> > 






Ut 


c 


Hi 





fs 







u 






>i 






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>^ 



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o O 



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w S - 



— -d o 



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c ^ ^ 
te 2 ° 

^ c c 

« « en 

cj a; tL> 
>. o o 

QDQ 



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U 



1) 


^ 


^ 


n 







Uc 







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PL, 


> 


>^ 



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>< >< 



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< 

o 



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Ph> 



Iz; Z ufiH 000 



8o8 



FOOD INSPECTION AND ANALYSIS. 



^ 



W pq 



(U o 



Pi 



PQ 



60 pq 



« pq 



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^1 



Pi 
w 

pq 

w 
h 

O 



pq 



p^ rt 






O T! -71 






U 



>H >H O >^ 



(LI (U 



^ 



P^ 



►5!P^ 



^ ^ 



fi ^ 



u 


0) 1) 


WJ 


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c 


C C 


rrt 


cs ni 


-C 


X! ^ 


u 


u 








^ 


^;5 



Ph 



OH) 



T-.y 








<:i CO 




<;« 




C C 


C! 


^ is 


■■?■ 










i-l 


P5pq 


pq 






ni ^ ^ ^ 

IH lU 1; <u 

U >1 >H >H 



en o 



■^> o 









:r! o O 



pq 



' S ° ^H g 

a^ &^ o^^ 

1^ "li ^iJ 

>^ bH >^ 



^13 



20 



s 8 



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(U C/3 O 



> pq 






:2 ^^ 



O O 

O, Oh 



W pqpq 



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..£ S3 
> o ° 



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bbO 



O eS* 

O PL| S 

u < 



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•c 









.20 



OS 

o 

l-J 
o 
U 
zO 

o & 

6^ S' 



o 






o 



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<pq 



2 t/i bO 



ARTIFICI/IL FOOD COLORS. 



809 



c c d c c c g 
& ^.2.2 .2 .2 .2 .2 -^ 






u u o . o 
rr" c^ rt r3 rt cti rt 



O O O O O C ;ii 

;z; 2 2; ^ :? z f^ 



o .5 



c o 



-d -d 
<u a; 

N N 



-uJ T3 



N _N .N c 



ao Q 



"out; 
^2 



-2^ 

tH O '-' 

m y o 



1; 




C 


•c 


ra 


c 








c 


<u 


^« 






>^ 



S & c 
^ c ° c 

^ ^.^ ^ o I 



o 'd 



& 

.s 

LI 
"J 

O Vt 



^ ^ 






.2 d .2 c c c .2 
t! ^ o J S ^ o 
'^ £ =^ -S -S 2 =-- 
o m o o o M o 



2« 



o o 



'^ ^ 



g & ^ 





^ ^ : : : 

_o _o ; ; ; 


u : 



^ MO 



CbCbC^bO&D^. 

.2ct;ccdccfe 

"tiajootioobo 

opqp£:;ooWoo;5 



o S 

I-' J? 



>- _2 



>^ :^ 



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0x1 



few 



bcO 



•^ o ^ 

bC o 3 






U >-. O , 









ii c -j^ 3 bc++ 



m^ t p rt 



8io 



FOOD INSPECTION AND ANALYSIS, 



9. s 






p-2 



^pq 



m 



O rt 



.Si c c 

fe OJ & 

SOCQ 
Q 



O ;:; 



« 
o 

.<!< 

o 
♦-1 
o 
u 

f>4 
o 

o 

I— I 

< 



-3« 



>-' -a 



O ni O 

pq «> 



c o 
a be 



-O XI 




u 


ii> 




N 




fi 












o 


f) 










o 


o 






9; 


>H 


QQ 





rt •:=-:? v> 



> O 






'o 'o '3 ^;g ^ 



3 S 



bC 

'3 

m 



o o 



i5 t^ s: & 



<u 



j3 o 



O «pq 



^ ^ 






c 2 

20 






O 



S^ I- £ t- 
j; 1) t. (u 
hc'u tea 

-2 o n- o 

Q Q 



!5| 



1^- 



u 



^.s^ 



'-3 o,c 



0-0 U^-o -a*-; 3 

< HH h-l I— I Ph 



.5 1) bO 
^ C - 



bC 

£: o c Ji 

bo ■*-* 4> Kn 

i> :r £. — 

.■a > bc o 

? p -p; 

^ ^ Z jS 



ARTIFICIAL FOOD COLORS. 



8ii 



%< 



a;3 



C <U 


c 


c c ~ c 


Violet 
o actio 
ue-viol 


"•2 
o 


o actio 
o actio 
enish b 
o actio 
Green 


Z- 


^ 


C5 



"O o 
1) -^ 

c ^ 

y 1, 



o 









P. 



, -C T3 -C 



o p ex, p 



'QQ 






O 






^ 2 
Opq 



c c c c 5 

.2 o o o S3 

O u o o o 

w ^ cj rt ^ 

O O O O O 



^ ^ 



•7! (^ ♦^ >^ 

C -o 

> 5^ 



CJ 



51 



W -r- = = 



!2i 



= .2 - 0-- 



P3 o>a ? 






C^Z 






o> 



:z^ 



i H 


+- 

a. 


+- 


>•* 




ji : 









O -s 



^"5 






^■■~'-=^ 3wt ■^•~ZZ r-^-c 
^= i3S:^S ZJ 





o 


^ 


m 


% 


o 


1 


H 






n 


> 



h&< 



^6 



X <s 



o'-'it: nl o 

! i I I i 



In U 

pacK 

o - . 

o c s « 

.5 3^ "--^ 
^ffi cs ^ u 

^■C K V, (8 

pqqjSh 
Mill 

pqqoScq 



8l2 FOOD INSPECTION ^ND /IN A LYSIS. 

Reagents. — In applying tests on the fiber, the reagents commonly used 
are as follows: Concentrated hydrochloric acid, concentrated sulphuric 
acid, sodium, hydroxide (io% solution), strong ammonia (28%), a hydro- 
chloric acid solution of stannous chloride, and concentrated nitric acid. 
The tests should be made on pieces of the fiber in small porcelain evapo- 
rating-dishes, which more readily than test-tubes show exact shades of 
color. In cases of suspected fluorescence, test-tubes should be used. 
Nitric acid is conveniently applied by a glass rod to the fiber. The 
stannous chloride should first be allowed to act in the cold. If no change 
occurs, gentle heat should then be applied, and finally boiling. 



ARTIFICIAL FOOD COLORS. 813 

REFERENCES ON COLORS. 

Arata, p. N. (Specielle analytische Methoden.) Zeits. anal. Chem., 28, p.639. 
Bellier, J. Detection of Artificial Coloring Matters in Wine. Ann. de Chim. Anal., 

5, igoo, p. 407; Abs. Analyst, 26, 1901, p. 42. 
Benedikt, R., and Knecht, E. The Chemistry of the Coal-tar Colours. London, 1889. 
Berry, W. G. Coloring Matters for Foodstuffs and Methods for their Detection. 

U. S. Dept. of Agric, Bur. of Chem., Circular No. 25. 
DoMMERGUE, G. Detection of Colors on Dyed Wool. Monit. Scient., t,^, p. 25; 

Abs. Jour. Soc. Chem. Ind., 8, p. 216. 
FoL, F. Testing of Dyestuffs. Jour. Chem. Soc, 28, 1875, p. 193. 
G1R.A.RD, P. Couleurs Employes dans les Matieres Alimentaires. Analyse des Matieres 

Alimentaires (Girard et Dupre), p. 68g. Paris, 1894. 
Green, A. G. On the Qualitative Analysis of Coal Tar Coloring Matters. Jour. 

Soc. Chem. Ind., 12, 1893, p. 3. 
Leeds, A. R. Tabellarische Uebersicht der kiinstlichen organischen Farbstoffe. 

Berlin, 1894. 
Looins, H. M. Report on Colors: The Solubility and Extraction of Colors and the 

Color Reactions of Dyed Fiber and of Aqueous and Sulphuric-Acid Solutions. 

U. S. Dept. of Agric, Bur. of Chem., Circular No. 35. 
M.ARTiNON, B. Jour. Soc. Dyers, 3, p. 124. 
NiETZKi, R. Chemie der organischen Farbstoffe. Berlin, 1901. 
Posetto, G. Composition of Vegetable Coloring Matters for Use in Confectionery. 

Zeits. Nahr. Unters. u. Hygiene, 9, 1895, p. 150. 
R.^wsoN, C, Knecht, E., and Lowenthal, R. A Manual of Dyeing. London, 1893. 
R.wvsoN, Gardner, and L.a.ycock. A Dictionary of* Dyes, Mordants, etc. 1890. 
Reichelmann and Leuscher. Detection of Coal Tar Colors in Pastry, Cakes, Fruit 

Products, etc. Zeit. fiir offentl. Chem., 8. 1902, p, 204; Abs. Analyst, 27, 1902, 

p. 276. 
Rota. A. R. A Method of Analyzing Natural and Artificial Organic Coloring Matters 

Analyst, 24, 1899, p. 41. From Chem. Zeit., 1898, p. 437. 
ScHULTZ, G., u. Julius, P. Taballarische Uebersicht der kiinstlichen organischen 

Farbstoffe. 1897. 
Translated by Green, A. G. A Systematic Survey of the Organic Coloring 

Matters, ist ed., 1894; 2d ed., 1904. 
Spaeth, E. Foreign Coloring Matters in Fruit Juices. Zeits. Unters. Nahr. Genuss., 

2, 1899, p. 633. 
Sostegni, L., and Carpentieri, F. (Specielle analytische Methoden.) Zeits. anal. 

Chem., 35, 1896, p. 397. 
Spiller, J. Identification of the Coal Tar Colors. Analyst, 6, 1881, p. 23. 
Tass.^rt, C. L. Des Matieres colorantes. Paris, 1890. 
Tolman, L. M. Coloring Matter in Food. U. S. Dept. of Agric, Bur. of Chem., 

Bui. 65, p. III. 
U. S. Food Inspection Decisions: No. 76. Dyes, Chemicals and Preservatives in 

Foods. No. 77. Certificate and Control of Dyes Permissible for Use in Color- 
ing Foods and Foodstuffs. 



8l4 FOOD INSPECTION AND ANALYSIS. 

Weber, H. A. Effect of Coal Tar Colors on Digestion. Am. Chem. Jour., 8, 1896, 

p. 1092. 
Weing'artner. Eine Anleitung zur Untersuchung der im Handel vorkommenden 

kunstlichen Farbstoffe. Zeits. anal. Chem., 27, 1888, p. 232. 
Weyl, T. Translated by Leffmann, H. The Sanitary Relations of the Coal Tar 

Colors. Philadelphia, 1892. 
WiNTON, A. L. The Use of Coal Tar Dyes in Food. Conn. Agric. Exp. Sta. Rep., 

1901, p. 179. 
Witt, O. N. Versuch. einer qualitativen Analyse der im Handel vorkommenden 

Farbstoffe. Zeits. anal. Chem., 26, 1887, p. 100. 



CHAPTER XVIII. 
FOOD PRESERVATIVES. 

Preservation of Food. — Various processes have from ancient times 
been knowm and used for arresting the fermentative changes which food 
products in their natural state undergo on long standing. These proc- 
esses include pickling with vinegar, drying, smoking, salting, preserving 
with sugar, and finally in the employment of heat in sterilizing and pas- 
teurizing, and of low temperature as in cold storage. All of them are 
still in use, and are universally regarded as unobjectionable. In addi- 
tion to these old and well-knowm methods of food preservation is the 
comparatively modern practice of arresting fermentation by the use of 
such antiseptic chemical agents as formaldehyde, beta-naphthol, boric, 
salicylic, benzoic, and sulphurous acids or salts of these acids, etc., in 
regard to the wholesomeness of which there is considerable difference 
of opinion. These substances depend for their efficiency on the more 
or less complete inhibition of bacterial growth. Nearly all exert a power- 
ful antiseptic influence, to such an extent that to accomplish their object 
only small quantities need be used in food. 

Apart from their toxic effects, a marked difference naturally exists 
between the employment of such substances as salt, sugar, and vinegar 
for food preservation, all of which are in themselves foods, and in the 
use of chemical agents that have no food value. The advocates of 
the use of chemical antiseptics claim that there are no authentic instances 
on record of injury from- the use of such small quantities of these sub- 
stances as are necessary to arrest decay, while there are many cases of 
injury arising from the use of foods which, while apparently wholesome, 
have undergone such fermentation as to develop ptomaines or other 
harmful toxins, and that because antiseptics prevent such spoiling of the 
food, their use is decidedly beneficial ; that there is, besides, no more 
reason why a prejudice should exist against the employment of these 

815 



8l6 FOOD INSPECTION AND ANALYSIS. 

newer chemicals than against sahpeter, which has long been used in the 
coming of meat, or against the cresols and phenols left as a product of 
smoking. 

The opponents to their use assert, that the addition to food of 
such antiseptic substances as prevent its decay also serves to retard 
the digestive processes when the food is eaten;' that many of these 
substances are drugs, and as such cannot fail even in small quantities 
to exercise a toxic effect of some sort on the system; that finally their 
use is objectionable, as allowing the employment in certain foods of 
old materials that have in some cases already undergone incipient 
decomposition before the addition of the antiseptic, and are thus un- 
wholesome. 

Regulation of Antiseptics in Food. — In the absence of legislation 
directly prohibiting the use of any of the above-named antiseptics, and 
in view of the difference of opinion regarding their toxic effects when 
present in small quantities, it is difficult to maintain a complaint under 
the general food laws as they exist in most states, basing the complaint 
solely on their harmfulness. In some localities certain antiseptics are 
specifically allowed and others are prohibited. Some of the states, as, 
for example, Massachusetts, have special laws under which it is required 
that in the case of all foods thus treated, the name and percentage of such 
antiseptics as are used must appear plainly on labels of the packages 
or containers thereof, such a provision being based on the assumption 
that the general public should be informed of what they are buying, where 
any doubt exists as to the wholesomeness o£ any ingredient present. 
Where such laws as these are in force, the chemist's task is compara- 
tively easy, in that conviction in court is not dependent on his individual 
opinion regarding the toxic effects of the antiseptic employed. 

Physiological experiments for testing the toxicity of these chemical 
preservatives were formerly confined to the lower animals, but no 
satisfactory results could be thus obtained. Later, metaboHsm experi- 
ments were made on human beings treated with varying amounts of the 
preservatives under carefully controlled conditions, but the results of 
these, though made by experts of unquestioned ability, do not agree. 
Even if any of these substances as used in food appear to have little or 
no effect on people in good health, they cannot be assumed to be equally 
harmless to those who are inclined to be delicate or sickly. Even though 
pronounced harmless in themselves, there is still the objection that the 
chemical preservatives may readily conceal unclean methods or materials. 
If perishable foods are free from preservatives and are sweet and 



FOOD PRESERf/ATiyES. 81/ 

untainted, the consumer has reason to beheve that clean and whole- 
some materials and sanitary processes were employed throughout in 
their manufacture. 

Commercial Food Preservatives. — A large number of commercial 
preparations are sold for purposes of preserving specilic articles of food 
and are put out under trade names that usually convey no suggestion 
of their true character. Some of these consist of a single antiseptic sub- 
stance, such as salicylic acid, ammonium fluoride, calcium sulphate, 
borax, or benzoic acid, while others are mixtures of several antiseptics, 
of which the following are typical examples, showing their composition 
as found, together with the amount of the mixture to be employed. 

A. For preserving sausage meat, using 8 ounces per loc pounds 
of meat: 

Borax 36% 

Salt 46% 

Sahpeter 18% 

(Colored with an anilin dye.) 

B. For preserving cider and kctcliup. 

A 34% solution of beta-naphthol in alcohol, using 2 fluid ounces to 
45 gallons of cider, or i^ ounces to 10 gallons of ketchup. 

C. For preserving beer, using i^ ounces per barrel of beer : 

Salt 45% 

Salicylic acid 27% 

Sodium carbonate and salicylate 28% 

D. For preserving chopped meats, us'ng i ounce to 50 pounds of 
meat' 

Sodium sulphite 65% 

Borax 35% 

E. Effcc-i\e for curing beef, hams, tongues, bacon, pig's feet, 
etc.: 

Borax 28% 

Boric acid 12% 

Sodium chloride 35% 

Potassium nitrate 25% 

F. For preserving m Ik and cream: 

Boric acid 75% 

Borax 25% 



>Ii 



FOOD INSPECTION AND ANALYSIS. 



G. For preserving jellies, jams, presences, mince-meat, and syrups, 
using from i to 2 ounces of preservative to 100 pounds of product: 

Sodium benzoate 5^% 

Boric acid 40% 

Sodium chloride 5% 

Sodium bicarbonate 5% 

H. For preserving ketchup and tomato pulp, using from 6 to 
8 ounces to 45 gallons of the product : 

Sodium benzoate 50% 

Sodium chloride 40% 

Sodium sulphite 10% 

/. Effective for keeping butter from becoming tainted or rancid, 
also for sah codfish, using 8 to 12 ounces per 100 pounds butter: 

Boric acid 25% 

Borax 50% 

Sodium chloride 25% 

J. For preserving eggs (surface application). A saturated solu- 
tion of salicylic acid in 3 quarts of v^ater, i quart strong alcohol and 7 
ounces of glycerin. 

FORMALDEHYDE. 

Formaldehyde (HCHO) is a gas formed by the action of a red-hot 
spiral of platinum wire on vaporized methyl alcohol. It is also pro- 
duced by the dry distillation of calcium formate. In the market it com- 
monly appears in the form of a 40% solution of the gas in water under 
the name of formalin, and for use as a food preservative dilute solutions 
of from 2 to 5 per cent strength are usually employed. Its use as a food 
preservative is comparatively modern. Formaldehyde, while not con- 
fined exclusively to milk products, is, as a matter of fact, more com- 
monly used in these than in other foods. Its prompt and direct action 
in checking or preventing the growth of lactic acid bacteria renders it 
especially desirable for use as a milk and cream preservative, from the 
standpoint of the dairy man who does not concern himself as to whether 
or not its use is injurious or illegal. 

When present in milk to the extent of i part formaldehyde to 20,000 
parts milk (a proportion quite commonly employed), the sample is kept 



FOOD PRESERyATiyES. 819 

sweet for four days in summer weather, when under ordinary conditions, 
the milk untreated would curdle in less than forty- eight hours. 

Determination of Formaldehyde in the Commercial Preservative. — 
(i) lodometric Method.'^— M\\ 10 cc. of the aldehyde solution (diluted 
if necessary to a strength not exceeding 3% of formaldehyde) with 25 cc. 
of tenth-normal iodine solution, and add drop by drop a solution of sodium 
hydroxide, till the color of the liquid becomes clear yellow. The solution 
is set aside for at least ten minutes, after which hydrochloric acid is added 
to set free the uncombined iodine, and the latter is titrated back with 
tenth-normal thiosulphate. Two atoms of iodine are equivalent to 
one molecule of formaldehyde, in accordance with the following reactions : 

6NaOH-f6I =NaI03+5NaI+3H,0. 

3CH,0 -f NalOg = 3CH2O2+ Nal. 

5NaI + NaI03-f 6HCl = 6NaCl+ 16+ 3H2O. 

(2) Method 0} Blank and Finkenbeiner.-\ — Three grams of the solu- 
tion are weighed into a tall Erlenmeyer flask, to which is then added 
from 25 to 30 cc. of twice-normal sodium hydroxide. 50 cc. of pure 
2.5 to 3 per cent hydrogen peroxide solution are next gradually run in 
during a space of from three to ten minutes, through a funnel placed in 
the neck of the flask to prevent spurting, and the solution is allowed to 
stand for two or three minutes, after which the funnel is washed with 
water. 

Finally the unused sodium hydroxide is titrated with twice-normal 
sulphuric acid, using litmus as an indicator. The less formaldehyde 
in the sample, the longer the mixture should stand after addition of the 
hydrogen peroxide, to complete the reaction. When less than 30% is 
present, it should stand at least ten minutes. 

Ascertain the percentage of formaldehyde, by multiplying by 2 the 
number of cubic centimeters of soda solution used, when 3 grams of the 
sample are taken. 

(3) Ammonia Method. % — Weigh 10 grams of the formaldehyde solu- 
tion into a flask, and treat with an excess of ammonia. Cork the flask 
and shake frequently during several days. The formaldehyde is by this 
process converted into hexamethylamine. 

Transfer the solution to a tared platinum dish, and evaporate nearly 

* Zeits. anal. Chem., 1897, 36, pp. 18-24; abs. Analyst, 22, p. 221. 

t Ber., 31 (17), 2979. 

J Conn. Exp. Sta., Annual Report, 1899, p. 143. 



S20 FOOD INSPBCTION AND ANALYSIS. 

to dryness on the top of a closed water-bath. Finally the dish is trans- 
ferred to a desiccator, and the drying continued over sulphuric acid to 
constant weight. The i)er cent of formaldehyde is calculated from the 
weight of the hcxamethylamine, making a correction for the residue left 
by the formaldehyde itself by direct evaporation: 

6CH,0 + 4NH,OH = (CH,)eN,-f loH^O. 

Or an excess of a standardized ammonia solution may be added in 
the first place, the excess of ammonia being distilled off and titrated with 
standard acid, calculating the per cent of formaldehyde by the amount 
of ammonia absorbed. 

Detection of Formaldehyde. — Methods have previously been given 
for the detection of formaldehyde in milk. Pure milk furnishes a con- 
venient reagent for the detection of formaldehyde in various preparations. 
A solution of the sample to be tested is acidified with phosphoric acid, 
subjected to distillation, and the first few cubic centimeters of the dis- 
tillate are tested for formaldehyde as follows: 

(i) Hydrochloric Acid and Ferric Chloride Test. — Add a few drops 
of the suspected distillate to aljout lo cc. of pure milk (previously proved 
free from formaldehyde) in a ])orcelain casserole, and carry out the test 
as described on page 180. 

(2) Hehner's Sulphuric Acid Test. — Apply the test as described on 
page 180 to 10 cc. of pure milk to which a few drops of the suspected 
distillate have been added. 

(3) Resorcin or Carbolic Acid Test. — To about 10 cc. of the distillate 
to be tested, add a few drops of a 1% solution of carbolic acid or resorcin, 
mix th()rf)ughly, and carefully pour the liquid down the side of a test-tube 
containing concentrated sulphuric acid. In the presence of formaldehyde, 
a rose-red zone is formed at the junction of the two liquids, sensitive to 
I part in 200,000. If formaldehyde be present to an extent exceeding 
I part in 100,000, a white turbidUy or precipitate is formed above the 
colored zone. 

(4) Phenylhydrazine Hydrochloride Test.* — One gram of phenyl- 
hydrazine hydrochloride and i^ grams sodium acetate are dissolved in 
10 cc. of water. Add 2 to 4 drops of this reagent, and an equal amount 
of sulphuric acid, to i or 2 cc. of the distillate to be tested in a test-tube. 
A green coloration is produced in the presence of formaldehyde. 

* Jour. Am. Chem. Soc., 22, p. 135. 



FOOD PRESERyATIVES. 82 1 

If present in a very small amount (say i part formaldehyde in 200,000), 
heat is necessary to bring out the color. 

Determination of Formaldehyde. — The exact quantitative determina- 
tion of formaldehyde in food products is difficult, owing to its extreme 
volatility as well as the uncertainty of the compounds which it forms with 
])roteins. A rough idea of the amount present may often be gained by 
the intensity of the colorations produced in carrying out the various 
(qualitative tests. 

Formaldehyde in the small amount present in food products may ho. 
roughly determined by the potassium cyanide method (j). j8i), on 
separate portions of the distillate of about 20 cc. each, collecting the 
distillate as long as an appreciable amount of formaldehyde is shown 
therein. 

BORIC ACID. 

Boric or boracic acid is commonly obtained in impure form from 
lagoons or fumaroles of volcanic origin in Tuscany. It is afterwards 
purified by recrystallization. It is weakly acid, and readily soluble in 
water and in alcohol. Its alcoholic solution, even when the acid is present 
in small quantity, burns with a characteristic green flame. The acid 
is quite volatile with steam. 

Borax, the most commonly known salt of boric acid, is found native 
in Italy, California, and elsewhere, and is also made from boric acid. 
It is mildly alkaline, and readily soluble in water. 

Boric acid and borax, either used separately or mixed, ha\'e long been 
used as preservatives, especially in animal foods. A mixture of 3 parts 
boric acid and i part borax has been found very effective as a milk and 
butter preservative, as well as for meat products. 

Determination of Boric Anhydride in Commercial Preservatives. — ■ 
Gladding Method.^- — A 150-cc. fiask, Fig, 117, is arranged with a doubly 
j)erforated stopper having two tubes, one of which, the inlct-tubc reach- 
ing nearly to the bottom, connects it with a larger flask, while the other 
or outlet-tube communicates with a Liebig condenser, which in turn 
delivers into a receiving-flask. In the 150CC. flask, i gram of the 
powdered sample is placed, with about 20 cc of 95% methyl alcohol and 
5 cc. of 85% phosphoric acid. The larger flask is then filled two-thirds 
full of methyl alcohol, and heated on the water-bath after the apparatus, 
has been connected up. Heat is also applied to the 150-cc. flask, the 

* Jour. Am. Chem. Soc, 20, 1898, p. 288. 



822 



FOOD INSPECTION AND ANALYSIS. 



whole arrangement being such that a continuous current of methyl alcohol 
vapor bubbles through the liquid in the smaller flask, the heat being so 
regulated that from 15 to 25 cc. of methyl alcohol remains in the 150- 
cc. flask, while about 100 cc. of distillate passes into the receiving-flask 
in half an hour. Continue the distillation till all the acid has passed 
over, which is usually accomplished by distilling 100 cc. By a gentle 
aspiration upon the receiving-flask, loss by leaking may be avoided. 




Fig. 117. — Apparatus for Determining Boric Acid According to Gladding. 

Prepare a mixture of 40 cc, of glycerin and 100 cc. of water, and care- 
fully neutralize, using phenolphthalein as an indicator. Add this mixture 
to the distillate, and titrate the whole with tenth-normal sodium hydroxide. 
Run a blank w^ith the reagents alone, deducting any acidity. For the fac- 
tors for calculation see page 824. 

Detection of Boric Acid and Borates. — These are best tested for in 
most cases in a solution of the ash of the sample, the quantity to be used 
for the test depending largely on the case in hand. With meat products 
and canned goods, about 25 grams are taken for the test, being first made 
distinctly alkaline with lime water, dried over the water-bath, and burned. 
The ash is boiled with from 10 to 15 cc. of water, and tests made on the 
solution. With such products as salt codfish, which is preserved by 
brushing or coating with boric mixture, portions of the coating may be 
scraped off and boiled in water, the tests being made on the aqueous 
solutions. 



FOOD PRESERI/JTIl^ES. 823 

(i) The Turmeric-paper Test.— The most delicate test for boric acid, 
free or combined, is made by the aid of turmeric-paper, prepared by soak- 
ing a smooth, thin grade of filter-paper in an alcoholic tincture of pow- 
dered turmeric. The paper is afterwards dried and cut into strips, which 
are kept for convenience in a wide-mouthed bottle in a dark place. 

Slightly acidulate the ash of the sample to be tested with a few drops 
of dilute hydrochloric acid, avoiding an excess of acid. Then dissolve the 
ash in a few drops of water and thoroughly saturate a strip of the tur- 
meric-paper in the solution. On drying the paper, if boric acid either free 
or combined be present, a cherry-red coloration will be imparted to the 
paper, the depth of color depending on the amount present. As a con- 
firmator}^ test, apply a drop of dilute alkali to the reddened paper, and 
a dark-olive color will be due to boric acid, sharply to be distinguished 
from the deep-red color produced when an alkaline solution is applied 
to ordinary turmeric-paper. The turmeric-paper reaction is delicate to 
I part in 8,000. 

(2) Tincture of Turjneric Test. — To the solution to be tested, slightly 
acidified with hydrochloric acid, add an equal volume of saturated tinc- 
ture of turmeric in an evaporating-dish, and heat for a minute or two. A 
red color, light or dark, depending on the amount of the preservative, 
is produced if boric acid be present, changed to an olive color by the 
addition of dilute alkali, after cooling. 

(3) The Flame Test. — A few cubic centimeters of alcohol are added to 
the dish containing the slightly acidulated ash of the sample to be tested, or 
to the acidulated dried residue from the evaporation of the aqueous solution 
of the suspected preservative, and after mixing by the aid of a stirring- 
rod, the alcohol is ignited. In the presence of any considerable portion 
of free or combined boric acid, a greenish tinge will be observed in the 
flame of the burning alcohol, especially at the first flash, due to the boric 
ether formed. This test is by no means as delicate at the paper test. 

Determination of Boric Acid in Foods. — (i) Thompson's Method.* — 
Add I or 2 grams of sodium hydroxide to 100 grams of the sample, and 
evaporate to dryness in a platinum dish. Char the residue thoroughly, and 
boil with 20 cc. of water, adding hydrochloric acid drop by drop till all but 
the carbon is dissolved. In burning, avoid too high a heat, simply charring 
sufficiently to insure a clear solution with water. Transfer by washing 
to a loo-cc. graduated flask, taking care that the volume does not exceed 
50 or 60 cc. Add half a gram of dr}^ calcium chloride, then a few drops 

* Analyst, 18, p. 184. 



824 fOOD INSPECTION AND ANALYSIS. 

of phenolphthalein solution, and next a io% solution of sodium hydroxide, 
till a permanent pink color persists. Finally add 25 cc. of lime-water. 
By this means all phosphoric acid is precipitated in the form of calcium 
phosphate. Make up to the loo-cc. mark with water, shake, and pour 
upon a dr}' filter. To 50 cc. of the filtrate add sufficient normal sulphuric 
acid to remove the pink color. Then add a few drops of methyl orange, 
and continue the addition of sulphuric acid till the yellow is just turned 
to pink. Tenth-normal sodium hydroxide is then added * till the liquid 
takes on a faint yellow, excess of alkali being avoided. The salts of the 
acids present at this time are all neutral to phenolphthalein except boric 
acid and carbon dioxide. Boil the solution to expel the carbon dioxide, 
cool, add a little more phenolphthalein, and a quantity of glycerin equal 
in volume to the solution. Finally titrate with tenth-normal sodium 
hydroxide to a permanent pink color. Each cubic centimeter of tenth- 
normal sodium hydroxide equals 0.0062 gram crystallized boric acid, 
H3BO3, or 0.0035 gram boric anhydride, B2O3, or 0.00955 gram crystal- 
lized borax, Na;jB,07,ioH20. 

(2) GoocJi's Method. — Mix 400 to 500 grams of the substance with 
10 grams of calcium hydrate, evaporate to diyness over a water-bath in 
a platinum dish, and burn cautiously to an ash. Dissolve the residue in 
cold nitric acid, and add an excess of silver nitrate to precipitate the chlo- 
rine. Filter, make up to 500 cc. with water, shake, and measure out 25 cc. 
\nto a 200-CC. flask fitted with a stopper provided with an outlet-tube, 
and with a separatory funnel forming virtually a thistle- tube, capable of 
being closed with a glass stop-cock. Through the outlet-tube connect 
the flask with a Liebig condenser provided with an adapter which can 
dip below the liquid in the receiver. As a receiver, use a 150-cc. tared 
platinum dish, which contains a weighed quantity of ignited lime in water. 

Add through the thistle-tube 10 cc. of methyl alcohol to the contents 
of the flask, close the stop-cock therein, and distill the contents in a paraf- 
fin-bath at a temperature of 140° C, constantly stirring the liquid in the 
receiver to keep it alkaline during the distillation. Add five successive 
portions of methyl alcohol of 12 cc. each to the distilling-flask, and con- 
tinue the distillation till all the alcohol has passed over. Finally evaporate 
to dryness the contents of the platinum dish, and ignite over a blast-lamp 
to constant weight. Multiply the increased weight due to boric oxide by 
2.728 to give the equivalent in borax. 

* If the value of the standard alkali solution is not absolutely certain, it had best be 
restandardized against pure crystallized boric acid, 0.31 gram of which should neutralize 
50 cc. of tenth-normal alkali. 



FOOD PRESERyATiyES. 825: 

SALICYLIC ACID. 

Salicylic acid (HC7H5O3) is a white, crystalline, strongly acid powder, 
made synthetically by treatment of carbolic acid with sodium hydroxide 
and carbon dioxide, or naturally from methyl salicylate (which occurs in- 
oil of wintergreen to the extent of about 90%), by treatment of the winter- 
green oil with strong potash lye. Most of the commercial salicylic acid is 
of the synthetic variety. Pure salicylic acid crystallizes from alcoholic 
solutions in 4-sided prisms, and from aqueous solution in long, slender 
needles. It melts at 155° to 156° C. It is slightly soluble in cold water 
(i part in 450), and much more so in hot water. It is readily soluble in 
ether, alcohol, and chloroform. 

It is frequently found on the market as a food preservative in the form 
of the much more soluble sodium salt, sodium salicylate, (NaCyHjOg),, 
which is, however, converted into salicylic acid when added to acid- 
fruit preparations, condiments, and liquors. 

Sodium salicylate is a white, amorphous powder, soluble in 0.9 parts 
water and in 6 parts alcohol. It is prepared by treating salicylic acid 
with a strong, aqueous solution of sodium carbonate, and afterwards- 
purifying. If a known weight of the powdered preservative be ignited, 
and a solution of the ash titrated with tenth-normal sulphuric acid, using 
cochineal as an indicator, each cubic centimeter of the acid is equivalent 
to 0.0160 gram of sodium salicylate. 

Salicylic acid is largely used as a preservative of jellies, jams, and 
fruit preparations, canned vegetables, ketchups, table sauces, wines,, 
beer, and cider. It is rarely used in milk and milk products, or in meats. 

Bucholz has shown that 0.15% of salicylic acid is sufficient to prevent 
bacteria from developing in ordinary organic substances, while as small 
a quantity as 0.04% produces a marked restraining influence. 

Small amounts of salicyhc acid occur naturally in grapes, straw- 
berries, and other fruits, but the amounts are too small to give distinct 
color reactions when only 50 grams of the fruit products are used for 
tests. 

Detection of Salicylic Acid. — If the sample to be tested is of a similar ■ 
nature to jelly, jam, ketchup, cider, etc., or capable of getting into aque- 
ous solution, slightly acidify the liquid or pasty material, diluted, if neces- 
sary, with weak sulphuric (if not already acid), and shake directly with 
an equal bulk of ether, petroleum ether, or chloroform, in a corked flask, 
or in a separatory funnel. If the sample be too thick in consistency to 



826 POOD INSPECTION AND ANALYSIS. 

shake directly, macerate in a mortar with alkahne water, and strain through 
cloth. Acidify the filtrate with dilute sulphuric acid, and then proceed 
to shake with the immiscible solvent as above. Separate by decantation or 
otherwise^ the immiscible solvent containing the preservative, if present, and 
allow it to evaporate in an open shallow dish, either at room temperature 
or at a low heat. In case an emulsion forms on shaking, which is quite 
apt to happen, especially with ether for a solvent, divide the whole mixture 
between two tubes of a centrifuge of the form shown in Fig. ii, and 
whirl for three minutes at a high rate of speed. This usually ser\^es to 
break up the most obstinate emulsion, so that it is easy to separate by 
decantation. If a considerable amount of salicylic acid be present, it 
will sometimes appear in the residue in the form of fibrous crystals. 

(i) To a portion of the dry residue add a drop of ferric chloride solu- 
tion. A deep purple or violet color indicates salicylic acid.* If doubt 
•exists as to the color, dilute with water, which often serves to bring out 
a distinctive purple coloration otherwise unobservable. 

(2) Another portion of the residue may be heated with methyl alcohol 
and sulphuric acid. If salicylic acid be present, the well-known odor of 
methyl salicylate will be produced. 

(3) A portion of the dry ether extract is warmed gently with a drop 
of concentrated nitric acid, and two or three drops of ammonia are added. 
Yellow ammonium picrate will be formed if a considerable quantity of 
salicylic acid be present, and a thread of wool free from fat may be dyed 
by soaking therein. This test is by no means as delicate as the ferric 
chloride color test. 

Instead of evaporating the ether solution of the salicylic acid to 
dryness, the author prefers to shake out the salicylic acid from the ether 
with dilute ammonia, evaporate the solution of ammonium salicylate nearly 
to dryness, and apply the tests given above to the concentrated solution. 
In this case the ether may be recovered. 

Determination of Salicylic Acid. — Dubois Method.-^ — In the case of 
ketchups and similar pulped materials place 50 grams in a graduated 
200-cc. flask, make slightly alkaline with ammonia, add 15 cc. of milk 

* Peters (U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 160) advises the use of chloro- 
form as more convenient for extraction when testing for salicylic acid, and recommends that 
the chloroform extract without evaporation be shaken in a test-tube with a drop of ferric 
chloride reagent and a little water. In the presence of salicylic acid, the violet color will 
be apparent in the supernatant aqueous layer. 

t Jour. Am. Chem. Soc, 28, 1906, p. 1616. U. S. Dept. of Agric, Bur. of Chem., Bui. 
107 (rev.), p. 179. 



FOOD PRESERyATI^ES. 827 

of lime (200 grams of quicklime in 2000 cc. water), complete the volume, 
shake and filter. Transfer 150 cc. of the filtrate to a separatory funnel, 
acidify with hydrochloric acid, and extract with four portions of 75 to 
100 cc. of ether. Wash the combined extract twice with 25 cc. of water, 
and distil off the ether slowly, allowing the last 20 to 25 cc. to evaporate 
spontaneously. Dissolve the residue in a small amount of hot water, 
make up to a definite volume with water, and add to an aliquot portion 
a few drops of a 2% solution of ferric alum to develop the color. Esti- 
mate the amount of saHcyhc acid by matching the color thus obtained 
with that produced in a solution containing i mg. of salicylic in 50 cc, 
using either a colorimeter or Nessler tubes for making the comparison. 

In the case of semisolid materials, such as mince meat, jams, etc., 
macerate 50 grams with water in a mortar previous to treatment as 
above described. 

Liquids and solutions of jellies and other materials free from pulp 
may be extracted with ether directly after acidifying. 

BENZOIC ACID- 

Benzoic Acid (HC7H5O2) is produced by the oxidation of a large 
number of organic substances, particularly toluene. It is also extracted 
by sublimation from gum benzoin, which exudes from the bark of the 
Styrax benzoin, a tree growing in Java, Sumatra, Borneo, and Siam. 
Most of the commercial benzoic acid is made from toluene by treatmeni 
with chlorine and subsequent oxidation. 

Benzoic acid crystallizes in leaflets, having a silky luster. It is odor- 
less when cold, is soluble in 200 parts of cold, and 25 parts of boiling 
water, and readily dissolves in alcohol, ether, and chloroform. Its melt- 
ing-point is 120°, and it sublimes at a slightly higher temperature . 

Sodium Benzoate (NaC7H502) is the salt most largely used in commer- 
cial preservatives, being much more soluble than the acid itself, into 
which, however, it is converted when put into acid fruit preparations. 
Sodium benzoate is prepared by adding benzoic acid to a concen- 
trated hot solution of sodium carbonate till there is no longer efferv'es- 
cence, and then cooling, and allowing the sodium benzoate to crj^stallize 
out. 

In titrating solutions of ignited sodium benzoate with tenth-normal 
sulphuric acid, each cubic centimeter of the standard acid is equivalent 
to 0.0144 gram of the benzoate. 



828 FOOD INSPECTION AND ANALYSIS. 

Sodium benzoate is a white, amorphous powder, having a sweetish, 
astringent taste. It is soluble in 1.8 parts of cold water, and in 45 parts 
of alcohol. Benzoic acid is commonly found as a preservative of 
ketchups, jellies, jams, and canned goods, and less often in wines and 
liquors. 

Benzoic acid occurs naturally in the cranberry and other berries of 
the Ericacecp. 

Detection of Benzoic Acid. — The sample is extracted with ether or 
chloroform in precisely the same manner as directed for salicylic acid. 
In fact, it is nearly always desirable to test the same sample for both 
these preservatives, since either and sometimes both are apt to be found 
in the same class of food products. For this purpose, the ether or chloro- 
form extract is conveniently divided and evaporated to dryness in separate 
dishes, one of the residues to be tested for salicylic, and the other for 
benzoic acid. A considerable amount of benzoic acid is apparent in the 
residue as shining crystalline scales or needles. 

In the author's experience a better procedure than evaporating the 
ether solution is to extract the benzoic acid from the ether by shaking 
with dilute ammonia, evaporate the solution of ammonium benzoate nearly 
to dryness, and apply tests to the concentrated solution. 

(i) Ferric Chloride Test. — A portion of the residue from the ether 
extract is dissolved in ammonia, and evaporated over the water-bath until 
neutral to test paper. The residue is stirred in a few drops of warm water, 
and filtered through a small filter into a narrow test tube. A drop of 
neutral ferric chloride (prepared by precipitating a portion of the iron 
from a solution of the salt by ammonia and filtering) is added, and 
in the presence of benzoic acid a flesh-colored precipitate of ferric 
benzoate is produced, very characteristic and unmistakable, because 
of its peculiar color, when the solution in which the test is made is color- 
less. It occasionally happens, however, in the case of jellies, jams, and 
ketchups, that these preparations are artificially colored with a dyestuff 
that persists by its depth of color in obscuring that of the ferric benzoate, 
especially when only a small amount of benzoic acid is present. Again, 
in such products as sweet pickles, a precipitate of basic ferric acetate 
might also come down with the ferric benzoate, and thus confuse. In 
such cases one of the following methods should be carried out. 

(2) Sublimaiion Method.^ — Evaporate an ammoniacal solution of the 



* Annual Report, Mass. State Board of Health, 1902, p. 486. Food and Drug Reprint, 
P-34. 



FOOD PRESERVATiyES. 829 

ether extract till neutral in a large watch-glass, by the aid of a gentle 
heat. Fasten with chps or otherwise a second watch-glass to the first, 
edge to edge, so as to form a double convex chamber, with a cut fiher- 
paper between. Place upon a small sand-bath and heat. Benzoic acid, 
if present, will sublime upon the surface of the upj)er glass in minute 
needles, recognizable under the microscope. It may further be tested 
by determining the melting-point of the crystals, or by treating the 
residue with ammonia, evaporating, and applying the ferric chloride 
test as above. 

(3) Mohler's Method.*' — The ether extract is evaporated and the 
residue heated with 2 or 3 cc. of strong sulphuric acid till white fumes 
appear; organic matter is charred and benzoic acid is converted into 
sulpho-benzoic acid. A few crystals of potassium nitrate are- then 
added. This causes the formation of metadinitrobenzoic acid. When 
cool, the acid is diluted with water, and ammonia added in excess, 
followed by a drop or two of fresh, colorless ammonium sulphide. The 
nitro compound becomes converted into ammonium metadiamidobenzoic 
acid, which possesses a red color. This reaction takes place immediately, 
and is seen at the surface of the liquid without stirring. 

(4) Petefs Oxidation Method.1i — This method depends on the oxida- 
tion of benzoic to salicylic acid by the action of sulphuric acid and 
barium peroxide, and should, of course, be applied only when salicylic 
acid has been first proved absent. J 

A portion of the residue, say o.i gram, from the ether or chloroform 
■extraction of the suspected sample, is transferred to a large test-tube, 
and dissolved in from 5 to 8 cc. of concentrated sulphuric acid. Small 
portions of barium peroxide are then successively added, and the tube 
shaken in cold water to keep the temperature down, using from 0.5 to 
0.8 gram of the peroxide in all. This should produce a permanent froth 
on the sulphuric acid solution. After standing for half an hour, the 
test-tube is filled three-quarters full of water, and the mixture shaken, 
quickly cooled, and filtered. The filtrate is then extracted with ether or 
chloroform, and the extract tested in the regular manner for salicylic 
acid. 



* Bui. Soc. Chim., 1890, 3, 414; U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 109. 
t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 160. 

X In view of the fact that saccharin acts in a similar manner to benzoic acid, the absence 
of saccharin must also first be established. 



830 FOOD INSPECTION AND AN /I LYSIS. 

Determination of Benzoic Acid. — La Wall and Bradshaw Method."^ 
— Shake thoroughly for five minutes 20 grams of the material, 2 grams 
of sodium chloride, 5 cc. of hydrochloric acid, and 25 cc. of. saturated 
solution of sodium chloride. Transfer to a moistened filter, collect the 
filtrate in a graduated 100-cc. flask, and wash the residue on the fiher 
with saturated solution of sodium chloride until the filtrate measures 
100 cc. Transfer the fihrate to a separatory funnel and shake out with 
three portions of chloroform, using 25 cc, 15 cc, and 10 cc respectively. 
Evaporate the chloroform at room temperature. If the residue is 
perfectly white and crystalline, as is usually the case, dry to constant 
weight over sulphuric acid in a desiccator. If the residue is slightly 
yellowish and oily, which rarely occurs, dissolve it in about 10 or 15 cc. 
of weak ammonia, filter into a separatory funnel, washing the filter and 
funnel with water. Acidulate with dilute sulphuric acid, again shake 
out with chloroform, evaporate, dry, and weigh. 

After obtaining the weight, dissolve the residue in from 3 to 5 cc. of 
alcohol, and titrate the solution with twentieth-normal potassium hydroxide 
solution. The volumetric and gravimetric resuhs usually will agree 
within I or 2 milligrams. 

Divide the solution after titration, which is slightly alkaline, into two 
portions. Test one portion for cinnamic acid by adding manganous 
sulphate solution, which, according to Scoville, forms with cinnamic acid 
a precipitate, while benzoic acid does not. To the other portion add 
neutral ferric chloride solution to confirm the presence of benzoic acid. 

The foregoing process is based on principles brought to notice by 
Moerk.t It is not applicable in the presence of salicylic acid or saccharin. 

The filtration in the case of high-grade ketchups is often exceedingly 
slow. This difficulty may be avoided by the following modifications 
devised by Bigelow : | 

To 200 grams of ketchup add 20 grams of finely powdered sodium 
chloride, and enough saturated solution of sodium chloride to make 
exactly one liter, shake thoroughly and allow to stand over night. Filter 
through a dry paper, transfer 500 cc. of the filtrate to a separatory funnel, 
add 5 cc. of sulphuric acid (1:5), and extract successively with 100, 50, 
50, and 25 cc. of chloroform. In other respects proceed as in the original 
method. 

* Am. Jour. Pharm., 80, 1908, p. 171. This method, although devised for ketchup, is 
also applicable to other vegetable products, 
t Proc. Penn. Pharm. Assn., 1905, p. 181. 
X A. O. A. C. Proc, 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 68. 



FOOD PRESERyATiyES. 831 

Hilyer's Method.* — This method is valuable as a check on the 
La Wall and Bradshaw method. After titrating the benzoic acid 
obtained as described in the preceding section, proceed as follows: 

Evaporate to dryness the accurately neutrahzed solution (which 
should not have even a slight alkaline rea:tion), and rcdissolve in a few cc. 
of alcohol saturated with silver benzoate. Filter if not clear, wash with 
a few drops of aldehyde-free alcohol saturated with silver benzoate, and 
treat with 10 to 15 cc. of a saturated solution of silver nitrate in aldehyde- 
free alcohol. Collect the precipitate in a Gooch crucible, care being 
taken that the asbestos filter is so prepared as to afford as rapid a filtra- 
tion as possible, wash with aldehyde-free alcohol, and finally with a 
little ether, heat in a water-oven until the ether is removed, cool, and 
weigh. Care must be taken to perform all the operations as quickly 
as possible to avoid separation of silver oxide. 

The aldehyde-free alcohol is prepared as described on page 745, witli 
the additional precaution of distiUing over sodium hydroxide after treat- 
ment with metaphenylenediamine hydrochloride. 

Sublimation Method. — The ether solution of the benzoic acid obtained, 
as in the case of salicylic acid, by shaking out with ether (page 826), 
is evaporated, dried over sulphuric acid, and subjected to subhmation 
in a suitable form of apparatus. The apparatus shown in Fig. 118, 
devised by Bird, has been adopted by the A. O. A. C.f The manipula- 
tion is as follows: 

Transfer the ether solution to tube a, evaporate the ether in a gentle 
current of air, dry in a vacuum desiccator until the contents are thor- 
oughly dry, and sublime the benzoic acid at 250° C, collecting the 
sublimate in tube b. 

During the subhmation, air is drawn very slowly through the appa- 
ratus (a wash bottle is used to gauge the speed of the current) to insure 
the volatilized benzoic acid passing into tube b. The joint between the 
two tubes is preferably made by means of a cork stopper. The most 
satisfactory results are obtained by placing the tube a inside of an oven 
the temperature of which is raised gradually until it reaches 250° C. 
The bulb of the tube b should be just outside of the oven, in order that 
the crystals may form therein. By means of this apparatus considerably 
higher results are obtained than by subliming on a watch-glass, as 
described above. 

* A. O. A. C. Proc. 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 74. 
I U. S. Dept. of Agric, Bur. of Chem., Bui. 90, p. 59; Bui, 107 (rev.), p. 181. 



«32 



FOOD INSPECTION AND ANALYSIS. 



The sublimate of benzoic acid collected in tube h may be removed 
by solution in alcohol, and the amount confirmed by titration. A sub- 
limate is sometimes obtained which somewhat resembles benzoic acid 
in appearance, and which has an acid reaction. Before applying the 
method, therefore, to any class of foods, blank experiments should be 
made to determine whether a sublimate is obtained under the same 
conditions from the ether extract of that class of foods. 




Fig. ii8. — Apparatus for Sublimation of Benzoic Acid. 

West's Distillation Method.^ — i. Apparatus.— The special form of 
double flask for distillation in a current of steam is the same as that 
employed by Hortvetf in determining the volatile acids of wine (Fig. 115)- 
The steam tube leading from the outer to the inner flask, being intro- 
duced half-way up the side of the inner flask, makes it possible to 
connect the apparatus in such a way that at the beginning of the 
operation the water in the outer flask will reach to the height of the 
contents of the inner flask. The side tube leading from the neck of 
the outer flask is provided with a rubber tube and pinch-cock for use 
in relieving the steam pressure and avoiding the danger of drawing the 
contents of the inner flask over into the outer flask. 

2. Process. — Weigh into the inner flask of the apparatus 10 grams, 
add 1.5 to 2.0 grams of paraffin free from volatile matter, and connect 
with the condenser. Add 10 cc. of concentrated sulphuric acid, drop 
by drop, through the funnel tube at such a rate as to complete the addition 



* Jour. Ind. Eng. Chem., i, 1909, p. 190. 
t Ibid., I, 1909, p. 31. 



FOOD PRESERV/tTIVES. 833 

in two to three minutes, mix thoroughly by gentle agitation, and allow 
to stand five to ten minutes after all apparent action of the sulphuric 
acid has stopped. Measure 150 cc. of distilled water into the outer 
flask, heat the water slowly to boiling, and continue the boiling until 
100 cc. of distillate have been collected, the rate of distillation being 
such as to yield this amount in 25 to 30 minutes. 

Filter the distillate into a separatory funnel, and rinse receiver and 
filter with two lo-cc. portions of water. Shake with three portions of ether, 
using 50 cc, 30 cc, and 20 cc, and wash the combined ether extracts 
by shaking with four 50-cc portions of water and a last portion of 
25 cc, which portion should not require more than a drop of tenth-normal 
alkali for neutrahzation, indicating the complete removal of volatile 
acids. Transfer the ether extract to a tared, wide-mouthed flask, and 
distil off the ether on the water-bath as quickly as possible. At just the 
point where ebullition of the ether ceases, remove the flask from the 
bath, blow air into it to remove the last traces of ether, and dry in a 
desiccator over night, or until constant weight is secured. 

The benzoic acid may also be determined by titration, in which case 
the filtration of the distillate, also the drying and weighing of the acid, 
may be omitted. The crystals of benzoic acid are dissolved in alcohol 
carefully neutralized immediately before each analysis, and the solution 
titrated with tenth-normal alkali. 

SULPHUROUS ACID AND THE SULPHITES. 

Free sulphurous acid in the form of sulphur fumes is extensively 
employed to bleach molasses, to disinfect wine casks, and to bleach 
and preserve dried fruits. This process is known as " sulphuring." It 
is stated that the sulphur dioxide combines with the acetaldehyde of 
wines forming aldehyde-sulphurous acid, which is comparatively harm- 
less. In the case of dried fruits it is believed to form compounds with 
the sugars. 

The sulphurous acid salts most commonly employed as food pre- 
servatives are the bisulphites of sodium and calcium, NaHSOs and 
Ca(HSO.-i)2. Others used to some extent are the normal sodium sul- 
phite, and also potassium and ammonium sulphite. The sulphites are 
usually commercially prepared by passing sulphurous acid gas through 
strong solutions of the carbonates. Acid sulphites are formed by an 
excess of the sulphurous acid in the solution of the sulphite. The acid 
sulphites are distinguishable from the sulphites by their reaction with 



834 FOOD INSPECTION AND ANALYSIS. 

litmus paper, the former being acid, while the latter are neutral or feebly 
alkaline. All of these salts have a bitter, salty, and highly sulphurous 
taste, and possess a very pungent, irritating odor. With the exception 
of normal calcium sulphite^ all of the above are readily soluble in water. 

The sulphites are most commonly used as preservatives of fruit juices, 
ketchups, fruit and vegetable pulps, wines, malt liquors and meat 
products. They are frequently mixed with other antiseptics, as with 
the salts of salicylic and benzoic acids. 

Detection and Determination of Sulphurous Acid. — The same methods 
are used for the detection of sulphurous acid as for its quantitative 
determination, except that in the former case weighed quantities need 
not be employed, and the precipitate obtained by the bariurn sulphate 
method need not be weighed. 

Distillation Method. — This method is adapted to all food products 
whether solid or liquid. 

Place 50 to 200 grams of the material in a 50-cc. flask, add water, 
if necessary, and 5 cc. of a 20% solution of phosphoric acid, and distil 
in a current of carbonic acid or steam * into water containing a few 
drops of bromine, until 100 cc. have passed over. If sulphides are present, 
as is true of decomposed meat products and possibly other food products, 
the steam from the distilling-flask before entering the condenser should 
be passed through a flask containing 40 cc. of a 2% neutral solution of 
cadmium chloride t or a 1% solution of copper sulphate. | These solu- 
tions effectually remove the hydrogen sulphide generated by the action 
of the phosphoric acid, without retaining any appreciable amount of 
sulphurous acid. To avoid escape of sulphurous acid the condenser tube 
should dip below the surface of the bromine solution. 

After the distillation is complete, boil until the excess of bromine is 
removed, add drop by drop while boiling an excess of barium chloride, 
allow to stand over night, filter (preferably in a Gooch crucible with a 
compact mat of woolly asbestos), ignite, and weigh. From the barium 
sulphate thus obtained, calculate the amount of sulphur dioxide. 

If desired, the distillate may be collected in a receiver containing a 
measured amount of iodine solution, and the excess thrated with thiosul- 
phate solution, using 1% starch paste as an indicator. This method, 
however, has the disadvantage that certain volatile organic substances 

* Gudeman, Jour. Ind. Eng. Chem., i, 1909, p. 81. 

t Home, U. S. Dept. of Agric, Bur. of Chem., Bui. 105, p. 125. 

X Winton and Bailey, Jour. Am. Chem. See, 29, 1907, p. 1499. 



FOOD FRESERyATiyES. 835 

act on the iodine solution. After the titration, therefore, add to the 
solution a few drops of barium chloride reagent. If no appreciable 
precipitate occurs, the presence of sulphurous acid should be disregarded. 

Direct Titration Method."^ — This method is applicable to sauternes 
and other white wines and to beer, but should not be used for other 
materials, unless found by experiment to yield accurate results. 

To 25 grams of the sample, iinely divided in water if sohd or semi- 
solid, add 25 cc. of a normal solution of potassium hydroxide in a 200-cc. 
flask. Shake thoroughly, and set aside for at least fifteen minutes 
with occasional shaking. 10 cc. of sulphuric acid (1:3) are then added 
with a little starch solution, and the mixture is titrated with N/50 
iodine solution, introducing the iodine solution quite rapidly, and adding 
it till a distinct fixed blue color is produced, i cc. of the iodine solution 
is the equivalent of 0.00064 gram SO2. 

FLUORIDES, FLUOSILICATES, AND FLUOBORATES. 

These substances all possess strong antiseptic qualities, and while 
no instances are recorded of the use of the last two classes of compounds 
in this country, the use of fluorides as a preservative of beer is practiced 
to some extent. The salt most commonly used is ammonium fluoride 
(NH4F), preparations of this salt being sold commercially under various 
trade names as beer preservatives. Ammonium fluoride exists as small, 
deliquescent, hexagonal, flat crystals. Its taste is strongly saline. It 
is soluble in water, and shghtly soluble in alcohol. Sodium fluoride 
(NaF) occurs as clear, lustrous crystals, soluble in water. 

Detection of Fluorides. — Modification of Blarez' Method. ■\ — Thor- 
oughly mix the sample and heat 150 cc. to boiling. Add to the boihng 
liquid 5 cc. of a 10% solution of barium acetate. Collect the precipitate 
in a compact mass, using to advantage a centrifuge, wash upon a small 
filter, and dry in the oven. Transfer to a platinum crucible, first break- 
ing up the dry precipitate and then adding the filter ash to the crucible. 
Prepare a glass plate (preferably of the thin variety commonly used for 
lantern-slide covers) as follows: First thoroughly clean and polish, and 
coat on one side by carefully dipping while hot in a mixture of equal 
parts of Canauba wax and paraffin. Near the middle of the plate make 
a small cross or other distinctive mark through the wax with a sharp 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 90. 

t Mass. State Board of Health An. Rep., 1905, p. 498. Chem. News, 91, 1905, p. 39. 



836 FOOD INSPECTION AND ANALYSIS. 

instrument, such as a pointed piece of wood or ivory, which will remove 
the wax and expose the glass without scratching the latter. Add a few 
drops of concentrated sulphuric acid to the residue in the crucible, and 
cover with the waxed plate, having the mark nearly over the center, and 
making sure that the crucible is firmly imbedded in the wax. Place 
in close contact with the top or unwaxed surface of the plate a cooling 
device, consisting of a glass cyhnder the bottom of which is closed with 
a thin sheet of pure rubber. Keep the cylinder filled with ice water, so 
that the wax does not melt. Heat the bottom of the crucible gently 
over a lov/ flame or on an electric stove for an hour. Remove the glass 
plate and indicate the location of the distinguishing mark on the unwaxed 
surface of the plate by means of gummed strips of paper, meh off the 
w^ax by heat or a jet of steam, and thoroughly clean the glass with a 
soft cloth. A distinct etching will be apparent on the glass where it 
was exposed, if fluoride be present. 

Detection of Fluoborates and Fluosilicates.* — Two hundred cc. of 
the wine or other sample are made alkaline with lime water, evaporated 
to dryness, and ignited. The crude ash is first extracted with water 
acidified with acetic acid, and the solution filtered. The insoluble residue 
is again ignited and extracted with dilute acetic acid, which is filtered off 
and added to the first extract. The filtrate contains the boric acid, if 
present, and this is tested for as directed on page 823. Calcium silicate 
or fluoride, if present, is in the insoluble portion. 

Incinerate the filter with the insoluble portion, transfer the ash to a 
test-tube, mix with some silica, and add a little concentrated sulphuric 
acid. A small U-tube should be attached to the test-tube, containing 
a ver)' little water. The test-tube is immersed for half an hour in a 
beaker of water kept hot on a steam-bath. In the presence of fluoride, 
silicon fluoride will be generated, and will be decomposed by the water, 
forming a gelatinous deposit on the walls of the tube. 

If both boric and hydrofluoric acids are found, the compound present 
is undoubtedly a borofluoride. If no boric acid is found, but silicon 
fluoride is detected, repeat the operation, but without the added silica. 
If the silicon skeleton is then formed, fluosilicate is probably present. 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 59, p. 63. 



FOOD PRESERVATIVES. 837 

BETA-NAPHTHOL. 

Beta-naphthol (C10H7OH) is a phenol, occurring naturally in coal- 
tar, but the commercial product is more commonly prepared artificially 
from naphthalene by digesting the latter with sulphuric acid, and fusing 
the product with alkali. It is a colorless, or pale buff-colored powder, 
with a faint phenolic odor and a sharp taste. It is slightly soluble in water, 
and readily soluble in alcohol, ether, and chloroform. Its melting-point 
is 122° C. In alcoholic solution it is neutral to litmus. 

It is used to some extent in alcoholic solution as a preservative of 
cider. 

Detection of Beta-Naphthol. — Buhe * states that if an ethereal extract 
of beta-naphthol is evaporated to dryness, and the residue dissolved in 
hot water made first faintly alkaline with ammonia, and then faintly acid 
with \ery dilute nitric acid, a beautiful rose color will be developed on 
the addition of a drop of fuming nitric acid or of a nitrite. He declares 
the test to be a delicate one, but it is apparently sometimes obscured by 
interfering substances, which the ether may dissolve. It should also be 
carried out in a faint light, as strong sunlight affects the color. 

Ferric chloride, when applied to an aqueous solution of beta-naph- 
thol, produces a greenish coloration. 

Shake about 50 grams of the sample to be tested with chloroform in 
a separatory funnel, evaporate the chloroform extract to a small volume 
(say I or 2 cc), transfer to a test-tube, add 5 cc. of an aqueous solution 
of potassium hydroxide (1:4), and warm gently. If beta-naphthol is 
present, a deep-blue color will appear in the aqueous layer, turning through 
green to light brown. 

ASAPROL, OR ABRASTOL. 

These are trade names for calcium a:-mono-suiphonate of beta- 
naphthol, Ca(CioH6S030H)2, a white, odorless, scaly powder, sometimes 
slightly reddish, obtained by the action of heated sulphuric acid on beta- 
naphthol, the resulting compound being afterwards treated with a calcium 
salt. It is readily soluble in water and alcohol, and is neutral in reaction. 
Its taste is at first slightly bitter, but rapidly changes to sweet. It decom- 
poses at about 50° C. 



Analyst, 13 (1888), p. 52. 



838 FOOD INSPECTION AND ANALYSIS. 

The writer is i.naware of any instance of the presence of this substance 
in foods, but its character is such as to adapt it for use as a preservative 
of wines and possibly other food products. It has long been regarded 
as a possible preservative, and the analyst should be prepared to 
encounter it at any time. 

Detection of Asaprol, — Sinahaldi^s Method.^ — The portion of the 
solution to be tested (say 50 cc.) is made slightly alkaline with ammonia, 
and shaken with 10 cc. of amyl alcohol in a separatory funnel. Alcohol 
is often useful in breaking up an emulsion if there is one. Separate the 
amyl alcohol extract, which if turbid is filtered, and evaporate to dry- 
ness. Wet the residue with about 2 cc. of nitric acid (i: i), heat on the 
water-bath till the volume is about i cc, and wash with a few drops of 
water into a narrow test-tube. Next add about 0.2 gram of ferrous sul- 
phate and ammonia in excess, a drop at a time, constantly shaking the 
solution. If a reddish-colored precipitate is formed, it is dissolved by 
the addition of a little sulphuric acid, and further additions of ferrous 
sulphate and ammonia are made as before. When a dark-colored or 
green precipitate appears, add 5 cc. of alcohol, dissolve in sulphuric 
acid, shake, and filter. If abrastrol be present to the extent of 0.0 1 gram 
or more, a red coloration is observed, while in its absence, the filtrate 
is colorless or faintly yellow. 

If the solution to be tested is a fat, it should be melted and extracted 
with hot 20% alcohol, which is evaporated to dryness, and the above test 
carried out on the dry residue. 

REFERENCES ON PRESERVATIVES AND THEIR USE IN FOOD. 

Abel, R. Zum Kampfe gegen die Konservierung von Nahrungsmitteln clurch Anti- 

septica. Hyg. Runds., 1901, 265-281. 
Annett, H. E. Boric Acid and Formaline as Milk Preservatives. Thompson Yates 

Lab. Reports, Liverpool, Vol. II, 1900, pp. 57-67. 
Baldwin, H. B. Toxic Action of Sodium Fluoride. Jour. Am. Chem. Soc, 21, 

1899, p. 517- 
Benedicenti. Action of Formaldehyde on Various Proteid Substances. Archw. f. 

Anat. u. Physiolog., 1897, p. 219. 
Behre, a., u. Segin, a. Ueber die Wirkung der Konservierungsmittel. Zeits. Unters. 

Nahr. Genuss., 12, 1906, p. 461. 

* Men. Sai., 1703 ,(4)> 1, P- '^4-'; U. S. Dept. Agric, Bur. of Chem., Bui. 59, p. 91. 



FOOD PRESERyATIVES. 839 

BisCHOFF, H., and Wintgen, U. Beitrage zur Konservenfaljrikation. Ztsch. fiir 

Hyg., Bd. 34, 1900, Heft 3, 496-513- 
Eliss and Now. Action of Formaldehyde on Enzymes. Jour. Exp. INIed., 4, 47. 
Chittenden, R. H. Influence of Borax and Boracic Acid on Digestion. Diet, and 

Hyg. Gazette, 9, 1893, 25. 
Chittenden and Gies. Effects of Borax and Boric Acid on Nutrition. New York 

Med. Jour., Feb., 1898. 

Experiments with Borax and Boric Acid on the Lower Animals. Am. Jour, of 

Phys., Vol. I, No. I, 1898. 
DiGHT, C. F. Effect of Boric Acid and Borax on the Human Body, and with Particular 

Reference to their Use as Food Preservatives. Minneapolis, 1902. 
GoxnN, R. Le Beurre et I'Acide Borique. Jour. d'Agricult prat., 1900, p. 14-16. 
Gruber. Ueber die Zuliissigkeit der Verwendung der Fluoride zur Konservierung 

von Lebensmittel. Das Oesterr. Sanitatsw., 1900, 4. 
■ Ueber die Zulassigkeit der Verwendung von Chemikalien zur Konservierung von 

Lebensmittel. Das Oesterr. Sanitatsw., 1900. 
GRtJNBAUM, A. S. Note on the Value of Experiments in the Question of Food Pre- 
servatives. Brit. Med. Jour., 1901, p. 1337. 
Halliburton, W. D. Remarks on the Use of Borax and Formaldehyde as Preserva 

tives of Food. Brit. Med. Jour., 1900, pp. 1-2. 
Heffter, a. Ueber den Einfluss der Borsaure auf die Ausnutzung der Nahrung. 

.\rbeiten aus dem kaiserlichen Gesundheitsamte, Bd. 19, Part i, 1902, p. 97. 
Hill, A. Antiseptics in Food. Pub. Health Jour., London, 11 (1901), 527. 
Hope, E. W. Preservatives and Coloring Matters in Foods. Thompson Yates Lab. 

Reports, Vol. Ill (1900), pp. 75-78. 
Jacobj, C, u. Walbaum, H. Zur Bestimmung der Grenze der Gesundheitsschadlich- 

keit der Schwefligen Saure in Nahrungsmitteln. Arch. Exp. Path. Pharm., 

54, 1906, p. 421. 
Kjckton, a. Ueber die Wirkung einiger sogenannter Konservierungsmittel auf 

Flackfleisch. Zeits. Unters. Nahr. Genuss., 13, 1907, p. 534. 
Kister, J. Ueber Gesundheitschadlichkeit der Borsauer als Konservierungsmittel fiir 

Nahrungsmittel. Zeit. f. Hygiene, Bd. 37, 1901, Heft 2, p. 225. 
Lauge, L. Beitrage zur Frage der Fleischkonservierungmittel. Borsaure, Borax und 

Schwefeligsauren Natronzusatzen. Mit einem Anhang. Milchkonservierung 

betr. Arch. f. Hygiene, Bd. 40, 1901, 2, pp. 143-186. 
Lebbin, G. Die Konservierung und Farbung von Fleischwaaren. Hyg. Rund., 11, 

No. 23. 
Lebbin u. Kallmann. Ueber die Zulassigkeit SchwefeUgsauer Salze in Nahrungsmit- 
teln. Zeits. fiir offentl. Chem., 7, 17, 324-334. 
Lebbin, G. Preservation and Coloring of Meat Produce. Translated from the 

German. 

Should the Use of Boric Acid as a Food Preservative be Permitted ? Translated 

from the German of Die medicinische Woche, Sept., 1901. 
Leffmann, H. Food Preservatives. Penn. Board of Agric, An. Rep., 1897, 535. 
■ Influence of Preservatives on Digestive Enzymes. Diet, and Hyg. Gazette, 14, 718. 

Hygienic Relations of Boric Acid and Borax. Diet, and Hyg. Gazette, 14, 171. 

Digestive Ferments and Preservatives. Jour. Frankl. Inst., 147 (1899), 97. 



840 FOOD INSPECTION AND ANALYSIS. 

Lepierre. Action of Formaldehyde on Proteids. Bui. Soc. Chem., 21 (i89Q),p. 729. 
LiEBREiCH, O. Effects of Borax and Boric Acidon theHuman System. London, 1902. 
The So-called Danger from the Use of Boric Acid in Preserved Foods. Lancet, 

1900, pp. 13-15. 
■ Die Verwendung von Formalin zur Konservierung von Nahrungsmitteln. Therap. 

Monatsh., 18, 1904, p. 59. 

Zur Frage der Bor-Wirkungen. Berlin, 1906. 

LOEW. Action of Formaldehyde on Pepsin and Diastase. Jour. f. prakt. Chem., 37, 

1888, p. lOI. 
Neitmann, R. O. Ueber den Einfluss des Borax auf dem Stoflfwechsel des Menschen. 

Arbeiten aus dem kaiserlichen Gesundheitsamte, Bd. 19, Pt. i, 1902, p. 89. 
POLENSKE. Ueber den Borsauregehalt von frischen und geraucherten Schweineschin- 

ken. Loc. cit., 167. 
Price, J. M. Die Einwirkung einiger Konservierungsmittel auf die Wirksamkeit 

der Verdauungsenzyme. Centralb. Bakt. II Abt., 14, 1905, p. 65. 
RiDEAL, S. Formalin as a Milk Preservative. Analyst, 20, p. 157. 

Disinfection and the Preservation of Food. London and New York, 1903. 

• On the Use of Boric Acid and Formic Aldehyde as Milk Preservatives. Public 

Health Jour., London, 11, 1901, p. 554. 
ROHARDT, W. Ueber Konservierung von fnschem Fleisch und iiber Fleischkonserven 

von Hygienischen- und Sanitats-polizeilichem Standpunkt aus. Vierteljahres- 

schrift f. gerichtl. Med., 1901, Heft 2, p. 321. 
RosT, E. Ueber die Wirkungen der Borsaure und des Borax auf den thierischen und 

menschlichen Korper, mit besonderer Beriicksichtigung ihrer Verwendung zum 

Konservieren von Nahrungsmitteln. Arbeiten aus dem kaiserlichen Gesund- 
heitsamte, Bd. 19, Part i, 1902, p. i. 
Zur Kenntnis der Ausscheidung der Borsaure. Arch, internat. Pharm. ThJr., 

15, 1905, P- 291- 
RosT, E., u. FR.A.NZ, F. Pharmakologische Wirkungen der Schwefligen Saure. Arb. 

Kaiserl-Gesundsheitsamt, 21, 1904, p. 312. 
Rt'BNER. Ueber die Wirkung der Borsaure auf den Stoffwechsel des Menschen. 

Loc. cit., Bd. 19, Part I, 1902, p. 70. 
SoNNTAG, G. Ueber die Quantitative Untersuchung des Ablaufs der Borsaureaus- 

scheidung aus dem menschlichen Korper. Loc. cit., no. 
Stroscher, a. Konservierung u. Keimzahlen des Hackfleishes. Arch. f. Hyg., 40, 

1901, pp. 291-319. 
TuNiNCLiFFE, F. W., and Rosenheim, O. On the Influence of Formaldehyde upon 

the Metabolism of Children. Jour, of Hygiene (London), Vol. I, 3, 1901. 
On the Influence of Boric Acid and Borax upon the General Metabolism of 

Children. Loc. cit., supra, 1901, Vol. I, No. 2, pp. 168-202. 
Vaughan, V. C, and Veenboer, W. H. The Use of Boric Acid and Borax as Food 

Preservatives. Am. Medicine, March, 1902. 
Vaillard, L. Les Conserves alimentaires de Viande. Rev. d'Hyg., 1900, pp. 782-792. 
Walbaum, H. Die Gesundheitsschadlichkeit der Schwefligen Saure and ihrer Ver- 

bindungen unter besonderer Beriicksichtigung der freien Schwefligen Saure. 

Arch. Hyg., 57, 1906, p. 87. 



FOOD PRESERy/iTiyES. 841 

Weitzel, a, Ueber die Labgerinnung der Kuhmilch unter dem Einfluss von Borpra- 
paraten und anderen chemischen Stoffen. Arbeiten aus dem kaiserlichen 
Gesundheitsamte, Bd. 19, Part i, 1902, p. 126. 

Wiley, H. W. Influence of Food Preservatives and Artificial Colors on Digestion 
and Health. U. S. Dept. of Agric, Bur. of Chem., Bui. 84. Part I, Boric 
Acid and Borax; Part II, Salicylic Acid and Salicylates; Part III, Sulphurous 
Acid and Sulphites; Part IV, Benzoic Acid and Benzoates; Part V, Formal- 
dehyde. 

Report of the Departmental Committee appointed to Inquire into the Use of 
Preservatives and Coloring Matters in the Preserving and Coloring of Food. 
497 pp. London. 

Report of Referee Board of Consulting Experts appointed by the Secretary 
of Agriculture, on the Influence of Sodium Benzoate on the Nutrition and 
Health of Man. Chittenden, R. H., Long, J. H., and Herter, C. A. U. S. 
Dept. of Agric, Report No. 88, Washington, 1909. 



CHAPTER XIX. 
ARTIFICIAL SWEETENERS. 

Under this head are included the intensely sweet coal-tar derivatives, 
such as saccharin, dulcin, and glucin, that possess no food value whatever 
in themselves. From their high sweetening power, in some cases several 
hundred times that of cane sugar, they are capable, when used in minute 
quantity, of imparting an appropriate degree of sweetness to food products, 
which, on account of the use of inferior materials, or by reason of the 
presence of inert or less sweet adulterants, would otherwise be lacking 
in this property. 

Such canned vegetables as sweet corn and peas are subject to treat- 
ment with saccharin, especially if by their age and condition before can- 
ning they are wanting in the sweet, succulent taste inherent in the fresh 
product. 

The sweetening power of commercial glucose is considerably less 
than that of cane sugar, so that when large admixtures of the glucose are 
used in such products as jellies, jams, honey, molasses, maple syrup, 
etc., to the exclusion of cane sugar, the presence of the glucose might in 
some cases be suggested by the bland taste of the food, unless reinforced 
by one of the artificial sweeteners. 

The analyst should therefore be on the outlook for one or another 
of these concentrated sweetening agents in all of the above classes of 
foods, especially in saccharine products wherein glucose is found to pre- 
dominate largely over the cane sugar, while the taste is not lacking in 
sweetness. It is doubtful how far the presence of artificial sweeteners 
can be regarded as a form of adulteration, unless their presence is legally 
and specifically prohibited. 

SACCHARIN. 

Saccharin or Gluside, Benzoyl sulphimide (CgH^.CO.SOzNH), is a 

white powder, composed of irregular crystals, whose melting-point, when 

842 



ARTIFICIAL SfVEETENERS. 843 

pure, is about 224° C. It is prepared from toluene, which by treatment 
with concentrated sulphuric acid is first converted into a mixture of 
■ortho- and para-toluene sulphonic acids. These are further converted into 
corresponding chlorides, and from the orthochloride, by treatment with 
ammonia, the imide is formed. It is soluble in 230 parts of cold water, 
30 parts of alcohol, and 3 parts of ether. It is sparingly soluble in chloro- 
form, but readily soluble in dilute ammonia. It is from 300 to 500 times as 
sweet as cane sugar, and, unlike cane sugar, it is not, when pure, charred 
by the action of concentrated sulphuric acid even on heating. Its aque- 
ous solution is distinctly acid in reaction. Pure saccharin, when heated 
under diminished pressure, can be sublimed without decomposition. 

The addition of i part of saccharin to 1,000 parts of commercial 
glucose renders the latter as sweet as cane sugar. 

A sodium salt of saccharin is found on the market, prepared by neutral- 
izing a solution of saccharin with sodium hydroxide or carbonate. The 
sodium salt crystallizes in the form of rhombic plates, forming a white 
powder readily soluble in water, and possessing nearly the same sweeten- 
ing power as saccharin. It is sometimes put up in the form of tablets 
for the use of diabetic patients as a substitute for sugar. 

Saccharin, aside from its sweet taste possesses, according to Fahlberg 
and List,* antiseptic properties, and on this account it is sometimes used 
in beer and other liquors. Squibb states that saccharin has about the 
same power as boric acid as an antiferment 

Detection of Saccharin in Foods. — If the sample to be tested is a solu- 
tion or syrup, render it acid, if not already such, with phosphoric acid, 
and extract with ether. In case of canned vegetables and similar goods, 
finely divide the material by pulping or maceration in a mortar, dilute 
with water, and strain through muslin. Acidify the filtrate, and extract 
with ether.f If an emulsion forms, use a centrifugal machine (p. 25), 
Separate the extract, evaporate off the ether, and test the residue for 
saccharin as follows : 

(i) Add to the residue, if it tastes sweet, a few cubic centimeters of 
hot waterj or preferably a very dilute solution of sodium carbonate, in 
which saccharin is more soluble. An intensely sweet taste is indicative 
of its presence. This test, if applied directly, ^\^ll sometimes fail, espe- 
cially in the case of beer, by reason of the extraction by the ether of various 

* Jour. Soc. Chem. Ind., IV, p. 608. 

t Allen states that a purer residue is obtained if the sample of beer be treated with lead 
acetate, and liltered before extraction with ether. 



844 FOOD INSPECTION AND ANALYSIS. 

bitter principles, such as hop resins, which by their strong, bitter taste 
mask the sweet taste of saccharin in the residue. Spaeth * recommends 
that such bitter substances be removed before extraction, which is done 
by treatment of 500 cc. of the beer with a few crystals of copper nitrate, 
or with a solution of copper sulphate. The flocculent precipitate formed 
need not be filtered off, but the liquid is preferably concentrated by evap- 
oration to syrupy consistency, acidified with phosphoric acid, and ex- 
tracted with three successive portions of a mixture of ether and petro- 
leum ether. After extraction, separation, and evaporation of the solvent, 
dissolve the residue in weak sodium carbonate. As small a quantity 
as 0.001% of saccharin can be detected in the final alkaline solution by 
its sweet taste. 

(2) Bornslein's Test.'\ — Heat the residue from the ether extraction 
of the acidified sample wdth resorcin and a few drops of sulphuric acid 
in a test-tube till it begins to swell up. Remove from the flame, an'l, 
after cooling till the action quiets down, again heat, repeating the heating 
and cooling several times. Finally cool, dilute with water, and neutralize 
with sodium hydroxide. X red-green fluorescence indicates saccharin. 
Gantter % states that it is useless to apply this test to beer, in view of the 
fact that ordinary hop resin gives the same fluorescence. 

(3) Schmidt's Tesl.^ — The residue is heated in a porcelain dish with 
about a gram of sodium hydroxide 1| for half an hour at a temperature 
of 250° C, either in an air-oven or in a linseed oil bath. This converts 
the saccharin if present into sodium salicylate. Dissolve the fused mass 
in water, acidify, and extract the solution with ether. Test the ether 
residue in the regular manner for salicylic acid with ferric chloride 
(p. 825), This test can obviously be applied only in the absence of 
salicylic acid, which should first be directly tested for. 

It is recommended that a mixture of equal parts of ether and petroleum- 
ether is preferable to the use of ether alone as a solvent of saccharin, as 
such a mixture, while readily dissolving saccharin, does not, like ether, 
dissolve other substances, which might form salicylic acid when fused 
with sodium hydroxide. 

Determination of Saccharin. — When saccharin is fused with an alkali 
and potassium nitrate, the sulphur is oxidized to sulphuric acid. On 

* Zeits. angewandte Chem., 1893, p. 579. 

t Zeits. anal. Chem., 27, p. 165. 

X Ibid., 32, 309. 

§ Rep. Anal. Chem., 30; Abs. Analyst, 12, p. 200. 

II Potassium hydroxide cannot be used instead of sodium hydroxide for the fusion. 



ARTIFICIAL SlVEETEhlERS. 845 

this principle depends the following method of Reischauer:* A known 
quantity of the beer or other liquid to be tested is concentrated by evapo- 
ration to about one-third its original volume, acidified with phosphoric 
acid, and extracted by repeated portions of ether. The combined ether 
extract is evaporated to small volume, and transferred to a platinum 
cnicible, in which it is further brought to dryness. It is then cautiously 
ignited with a mixture of about 6 parts sodium carbonate and i part potas- 
sium nitrate. Dissolve the fusion in water, acidulate with hydrochloric 
acid, and determine the sulphuric acid in the usual manner with barium 
chloride. The weight of the precipitated barium sulphate, multiplied 
by 0.785, gives the weight of saccharin. In view of the fact that only 
small quantities of saccharin are used in beer and other foods, it is best 
to employ a large portion of the sample for analysis. 

DULCIN. 

Dulcin or sucrol, para-phenetol carbamide (C2H5O.CeH4.NH.CO.NH2) 
is a white powder, composed of needle-like cr^'stals, sparingly ;.oluble 
in cold water, ether, petroleum ether, and chloroform. It dissolves in 
800 parts of cold water, 50 parts of boiling water, and 25 parts of 95% 
alcohol. It is readily soluble in acetic ether. Its melting-point is about 
173° C. It is not readily sublimed without decomposition. Dulcin is 
about four hundred times sweeter than cane sugar. 

When a mixture of dulcin and dilute sodium hydroxide is subjected to 
distillation, phenetidin goes over with the steam into the distillate. When 
this is heated with glacial acetic acid, phenacetin is formed, which may 
be tested for as follows: Boil with hydrochloric acid, dilute with water, 
cool, fdter if turbid, and add a few drops of a solution of chromic acid. 
A deep-red color indicates phenacetin. 

Detection of Dulcin in Foods. — In view of the comparatively slight 
solubility of dulcin in ether and chloroform, acetic ether is the best solvent 
for purposes of removing it from foods, first making it alkaline. 

(i) Bellier's Method.-\ — A portion of the sample to be tested is made 
alkaline and extracted with acetic ether. In the case of certain products 
it is best to subject them to varied preliminary treatment, depending on 
the case in hand. With such products as thin fruit syrups, simply make 
alkaline and shake out with acetic ether. In the case of thick fruit syrups, 
confectionery, and preserves, dilute with water, add an excess of basic 

* Abst. Analyst, ir, p. 234. 

t Ann. de Chim. Anal., 1900, V, pp. m-2,:ir> Abs. Analyst, 26, p. 43- 



846 FOOD INSPECTION AND ANALYSIS. 

lead acetate, remove the lead by precipitation with sodium sulphate^ 
filter, and make the filtrate alkaline. 

With wines, add 2 grams of mercuric acetate and a slight excess of 
ammonia, shake, and iilter. 

With beer, add to 200 cc. 2 or 3 grams of powdered sodium phospho- 
tungstate, and a few drops of sulphuric acid, shake, allow to stand for a 
few minutes, and filter. Make the filtrate alkaline with ammonia. 

Having thus obtained a clarified solution, use from 50 to 200 cc. of 
neutral acetic ether to say 500 cc. of the alkaline solution, and shake 
in a separatory funnel. Separate the extract, filter, and evaporate to 
dryness. If the dulcin exceeds 0.04 gram per liter, crystals will be appar- 
ent in the residue. If fats and resins are present in the residue, make 
repeated extractions with hot water, and evaporate to dr}mess. The 
purified residue is finally brought to dryness in a porcelain dish, and 
treated with i or 2 cc. of sulphuric acid and a few drops of a solution 
of formaldehyde. Let it stand for fifteen minutes, and afterwards dilute 
with 5 cc. of water. A turbidity or precipitate indicates dulcin. 

(2) Jorissen's Test* — The residue from the acetic ether extract of 
an alkaline solution of the sample is treated with 2 or 3 cc. of boiling 
water in a test-tube, and a few drops of mercuric nitrate f are added. 
Heat the tube and its contents for five minutes in a boiling water-bath,, 
withdraw, and disregarding any precipitate, add a small quantity of lead 
peroxide. On the subsidence of the precipitate, which quickly occurs, 
a fine violet color appears for a short time in the clear upper layer in 
presence of o.ooi gram of dulcin. 

(3) Morpurgo^s Mcthod.X — To the acetic ether residue, evaporated to 
dryness in a porcelain dish, add a few drops of phenol and concentrated 
sulphuric acid, and heat a few minutes on the water-bath. After cooling, 
transfer to a test-tube, and with the least possible mixing pour ammonia 
or sodium hydroxide over the surface. A blue zone at the plane of con- 
tact between the two layers indicates dulcin. 

Determination of Dulcin. — For a quantitative determination, Bellier's 
method is carried out on a weighed or measured portion of the sample, 
as follows: In the case of alcoholic beverages first expel the alcohol by 

* Chem. Zeit. Rep., 1896, p. 114. 

t The mercuric nitrate is prepared by dissolving 2 grams of mercuric oxide in dilute 
nitric acid, adding sodium hydroxide solution till a slight permanent precipitate is formed, 
diluting to 15 cc, and decanting the clear liquid. 

J Zeits. anal. Chem., 1896, 35, p. 104; U. S. Dept. of Agric, Bur. of Chem., Bui. 65, 
p. 80. 



ylRTIFlCML SIVEETENERS. "^ 847 

evaporation, and make up to the original volume with water. Treat 
the various food preparations with the appropriate clarifying reagents, 
as in Bellier's qualitative test (p. 845), and, after filtering and making 
alkaline, extract twice with 50 cc. each of acetic ether. The residue, 
is purified if necessary by extraction with hot water as above described, 
and the final residue is dissolved in i to 5 cc. of concentrated sulphuric 
acid. A few drops of formaldehyde are added. The solution is allowed 
to stand for fifteen minutes, and then diluted to ten times its volume 
with distilled water. After twenty-four hours, collect the precipitate on a 
tared filter, wash with water, dry, and weigh. 

GLUCIN. 

This comparatively new sweetening agent is the sodium salt of a 
mixture of the mono- and di-sulphonic acids of a substance having the 
composition Ci9HmN4. In the market it appears as a light-brown powder, 
readily soluble in water. It is insoluble in ether and chloroform. It 
decomposes without melting at about 250° C. It is three hundred times 
sweeter than cane sugar. 

A color reaction with glucin is obtained by dissolving it in dilute 
hydrochloric acid, cooling by immersing the test-tube in water, and to 
the cold solution adding a little sodium nitrite solution. Finally, to the 
liquid is added a few drops of an alkaline solution of beta-naphthol, and 
a red coloration is produced. With resorcin or salicylic acid in alkaline 
solution, the color will be yellow. 

REFERENCES ON ARTIFICIAL SWEETENERS. 

Allen, A. H. The Detection of Saccharin in Beer. Analyst, 13 (1888), p, 105. 
Bellier, J. The Detection and Estimation of Dulcin in Beverages. Ann. de Chem. 

Anal., 1900, 5, 333; Abs. Analyst, 26, 1901, p. 43. 
Berlioz, F. Influence of Saccharin upon Digestion. Chem. Zeit., 1900, p. 416; 

Abs. Analyst, 25, 1900, p. 233. 
BucHKA, K. V. Kiinstliche SiissstofTe. Vereinbarung. v. Nahr. u. Genuss. f. d. deuts. 

Reich., Heft II, p. 134. Berlin, 1899. 
CoHN, G. Ueber kiinstUche Sussstoffe. Apoth. Ztg., 1898, 13, pp. 796 and 804. 
Defotjrnel, H. Determination of Saccharin in Food Products. Abs. Analyst, 26, 

1 90 1, p. 268. 
Dennhardt. Versuche zum Nachweise des Dulcins. Ber. d. deutsch. pharm. Ges.> 

1898, 6, p. 287. 
Gantter, F. The Detection of Saccharin in Beer. Abs. Analyst, 18, 1893, p. 184. 
Gravill, E. D. Notes on Saccharin. Pharm. Jour., 8, 1887 (3), pp. 18, 337. 



848 FOOD INSPECTION /IND ANALYSIS. 

Herzfeld, a., and Wolff, F. Ueber die Eestimmung der kiinstllchen Siissstoffe in 

Nahningsmitteln. Zeits. f. Unters. d. Nahr. u. Genussra., 1898, i, p. 839. 
JoRissEN, A. Neue Methode zum Nachweise von Dulcin in Getranken. Jour, de 

Pharm. de Liege; Chem. Centr., 1896, i, p. 1084; Abs. Analyst, 21, 1896, p. 164. 
Leys, A. A New Test for Saccharin. Ann. de. Chim. anal., 1901, 6, p. 201; Abs. 

Analyst, 26, 1901, p. 321. 
Reid, E. E. Valuation of Saccharin. Am. Chem. Jour., 1899, 21, p. 461. 
RuGER, C. Ueber das Fahlberg'sche Saccharin. Gesundheit, 1888, 13, p. 241. 
ScHiHTT, C. Ueber den Nachweis der o. Sulfamin-benzoesauer, genannt "Fahl- 

berg'sches Saccharin." Rep. fur anal. Ch., 1887, 7, p. 437. 
Spath, E. Ueber den Nachweis des Saccharins im Bier, Zeits. f. angew. Chemie, 

1893, P- 579- 
Sutherland, D. A. Saccharin. Jour. Soc. Chem. Ind., 6, 1887, p. 808. 

Taylor, W. A. H. Commercial Saccharine. Pharm. Jour., 18S7, 88 (3), 18, 377. 

Thoms, H. Ueber Dulcin. Ber. d. deutsch. pharm. Gesellsch., 1893, 3, 133. 

Wanters, J. Nachweis des Saccharins im Bier. Moniteur scientifique, 4, 1896, 10, 

146. 



CHAPTER XX. 

FLAVORIXG EXTRACTS AND THEIR SUBSTITUTES. 

Of the three great groups of organic compounds essential for nutri- 
tion, the fats and proteins in a state of purity are almost tasteless, as is 
also true of starch, dextrin, and cellulose of the carbohydrate group. 
Only the sugars have a pronounced taste. The flavor of food products, 
aside from their sweetness, is largely due to minor constituents, such 
as organic acids, ethers, essential oils, etc., which serve chiefly to render 
the products acceptable to the palate, thereby contributing to their 
digestibility. Many culinary preparations lacking in flavor, but not in 
nutritive value, are commonly mixed with substances which supply this 
deficiency. Spices and flavoring extracts belong to the class of materials 
added mainly if not entirely for their zest-giving properties. 

By far the most extensively used flavoring extracts are those of vanilla 
and lemon, and in comparison with these the sale of all other varieties 
is comparatively insignificant. These two favorite extracts are employed 
in nearly every household, and form a necessary adjunct to almost all 
forms of desserts, cakes, and confections, as well as to a wide variety 
of commercial preparations. Others of some importance are extracts of 
orange, almond, wintergreen, peppermint, rose, and certain spices. Imita- 
tion fruit flavors are used in cheap confectionery, ice cream, etc., and 
are of questionable wholesomeness. 

VANILLA EXTRACT. 

The V-inilla Bean is the source of pure vanilla extract, besides being 
used in chopped form directly as a flavoring agent. It is the fruit of 
the plant of the Vanilla plaiiijolia, or flat-leaved vanilla. This climbing, 
perennial plant belongs to the orchid family, and is indigenous to Central 
and South America and the West Indies, but by far the highest prized 
beans are cultivated in ^Mexico. While different varieties differ in some 
details, the best cured beans of commerce, as a rule, are from 20 to 25 cm. 
in length and from 4 to 8 mm. thick, drawn out at their ends and curved 

849 



850 FOOD INSPECTION AND ANALYSIS. 

at the base. They are rich dark brown in color, of a soapy or waxy 
nature to the touch, deeply rifted lengthwise, and covered with fine frost - 
like crystals of vanillin. When cut cross-wise, the bean exudes a thick, 
odorless juice, containing calcium oxalate crystals. 

The cross-section of the bean is ellipsoidal in shape. The thick 
brown walls inclose a triangular cavity, in which arc the lobed placentas. 
Between these arc papillae, secreting a finely granular, yelloM^, balsam- 
like substance that contributes much to the flavor of the extract, and 
helps to give the cut bean its dehcious odor. 

When first gathered, the beans are yellowish green, fleshy, and with- 
out odor, developing their peculiar consistency, color, and smell by the 
process of fermentation or " sweating," which differs in various countries. 
According to the best methods the beans are sun-dried for nearly a month, 
being alternately pressed lightly between the folds of blankets, and 
exposed to the air. After the curing, they are packed in bundles. 

Quicker methods of curing consist of the use of artificial heal and 
calcium chloride for drying, but the products so prepared are considered 
inferior in quality. 

The Mexican vanilla beans are of the choicest grade, and command 
a high price, sometimes reaching fifteen dollars per pound. The Bourbon 
beans, grown in the Isle of Reunion, are next in grade. These beans 
are shorter than the Mexican and much less expensive. They resemble 
the Tonka bean in odor. Beans from Seychelles and Mauritius are 
even shorter than the Bourbon beans, and are largely exported to England. 
Cheaper varieties are those from South America, which do not bring 
half the price of the Mexican beans, and the cheapest are the Tahiti beans 
and so-called " vanillons," or beans of the wild vanilla {Vanilla pompona). 
These latter are used more in sachet powders and perfumes, possessing 
an odor not unlike heliotrope. 

Composition of the Vanilla Bean. — The following are results of the 
analyses of two varieties of vanilla beans, according to Konig: 

A, B. 

Water 25. 

Nitrogen bodies 4 . 

Fat and wax 6 . 

Reducing sugar 7 . 

Non-nitrogen substances 30. 

Cellulose 19. 

Ash 4. 



•»5 


30-94 


-87 


2.56 


-74 


4.68 


.07 


9.12 


-50 


32.90 


.60 


15-27 


•73 


4-53 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 851 

Vanillin. — Under "non-nitrogen substances" in the above table is 
included vanillin, the principle to which vanilla ovv^es its peculiar odor. 
This body (CgHsOa) is the methyl ether of protocatechuic aldehyde, and 
is found on the surface of the bean in fine crystalline needles. It has a 
sharp but pleasant flavor, is soluble with difficulty in cold water, but 
readily soluble in hot water, ether, alcohol, and chloroform. Its melting- 
point is 80° to 81° C. and it sublimes at 280°. It is present in vanilla 
beans to an amount varying from i to 2f per cent, and it is a curious fact 
that varieties of bean most highly prized possess the least vanillin. This 
is shown by Ticmann and Harmann as follows: 

Mexican beans i .69% vanillin 

Bourbon beans 2 . 48% " 

Java beans 2 . 75% " 

While vanillin may be readily extracted by alcohol and other solvents 
from the beans, such a product would be far too expensive to compete 
with the commercial synthetic vanillin, an artificial product, chemically 
identical with the vanillin from the bean. Synthetic vanillin was formerly 
made from the glucoside coniferin by oxidation with chromic acid. It 
is now largely obtained by oxidizing the eugenol of clove oil with alkaline 
potassium permanganate. 

If ferric chloride be added to an aqueous solution containing vanillin, 
a dark-blue coloration will be produced. 

Besides vanillin, the bean contains notable quantities of wax, fat, 
sugar, tannin, gum, and resin. 

Exhausted Vanilla Beans are sometimes found on sale, which have 
been deprived of their vanillin by being soaked in alcohol, after which 
they are coated with some artilicial substitute, presenting the same frosty 
appearance as the natural vanillin crystals. This may be accomplished 
by rolling the beans in benzoic acid. Benzoic acid crystals are readily 
distinguished from those of vanillin under the microscope. 

Composition of Vanilla Extract.— Vanilla extract is a dilute alcoholic 
tincture of the vanilla bean, sweetened by cane-sugar. To be perfectly 
pure it should contain no other added substances, with the possible excep- 
tion of glycerin, and many of the best brands are free from this. In 
practice it is variously prepared, but the following method of the U. S. 
Pharmacopoeia is a typical one: 

"Vanilla, cut into small pieces and bruised, 100 grams. 

"Sugar, in coarse powder, 200 grams. 



852 



FOOD I\JSPECTION ^ND y4NALYSIS 



"Alcohol and water, each, a sufficient quantity to make i,ooo cc. 

"Mix alcohol and water in the proportion of 650 cc. of alcohol to 
350 cc. of water. Macerate the vanilla in 500 cc. of this mixture for 
twelve hours, then drain off the liquid and set it aside. Transfer the 
vanilla to a mortar, beat it with the sugar into a uniform powder, then 
pack it in a percolator, and pour upon it the reserved liquid. When this 
has disappeared from the surface, gradually pour on the menstruum, 
and continue the percolation, until 1,000 cc. of tincture are obtained." 

The best extracts are produced by allowing the cut beans to macerate 
in the alcohol for several months. 

Five vanilla extracts, made by Winton and Silverman from beans 
of different grades, strictly according to the pharmacopoeial formula 
as above, were analyzed by them with the following results: 

AN.\LYSES OF VANILLA EXTRACTS, U. S. P., MADE IN THE CONNECTICUT 
EXPERIMENT STATION LABORATORY. 



Grade of Bean. 


Specific 
Gravity. 


Vanillin, 
Per Cent. 


Alcohol 

bv 
Weight, 
Per Cent. 


Total 
Residue, 
Per Cent. 


Cane 

Sugar, 

Per Cent. 


Residue 

Other than 

Cane 

Sugar, 

Per Cent. 


Mexican (whole) 

(cut) 


I. 0159 
I. 0146 
I. 0109 
I. 0166 
I. 0104 


0.125 
0.065 
0.215 
0.138 
0.108 


37-96 
39-92 
38-58 
38-32 
38-84 


22.60 
23.10 
22.00 
23-13 

21-75 


19.90 
19.20 
19.00 
20 . 40 
20.00 


2.70 
3-9° 
3-00 
2-73 
1-75 


South American (whole). .. 
Sourbon (whole) 


Tahiti (whole) 





Vanillin Content. — The writer has found in his examination of a 
large number of brands of vanilla extract that gave every indication of 
purity that the content of vanillin varied from 0.05 to 0.200 per cent. 
It is rare that a pure extract will show more vanillin than the latter figure, 
though one of Winton 's extracts runs as high as 0.215. The writer has 
found extracts with 0.250 or more of vanillin, but believes them to have 
been reinforced with the artificial substance. The flavor of the extract 
depends not only on the vanillin, but also on the various resinous and 
other extractive matters which it contains. 

Use of Alkali. — Some manufacturers employ dilute alkali, generally 
potassium bicarbonate, to aid in dissolving out the resinous matter from 
the bean, and to enable them to use a more dilute alcohol. The resulting 
product made by this process is distinctly inferior, both in taste and odor. 

Alcohol in pure extracts varies between the limits of 20 and 40 per cent. 

The Tonka Bean forms the basis of many of the cheaper so-called 
vanilla extracts on the market. It is the seed of the large tree, native to 



FLAi/ORING EXTRACTS AND THEIR SUBSTITUTES. 853 

Guiana, known as Dipterix (or Coumarouna) odorata. The pods arc 
almond-shaped, and contain a single seed, from 3 to 4 cm. long, shaped 
like a kidney bean, of a dark-brown color, having a thin, shiny, rough, 
brittle skin, and containing a two-lobed oily kernel. 

Coumarin (C9Hg02), the active principle of the Tonka bean, is the 
anhydride of coumaric acid. It occurs in the crystalline state between 
the lobes of the seed kernel. Coumarin occurs also in many other plants. 
It may be extracted from the beans by treatment with alcohol. It crys- 
tallizes in slender, colorless, needles, melting at 67° C. It has a fragrant 
odor and burning taste. It is very shghtly soluble in cold water, but 
readily soluble in hot water, ether, chloroform, and alcohol. One pound 
of cut beans yields by alcoholic extraction about 108 grains of coumarin. 
The latter may be synthetically prepared by heating sahcylic aldehyde 
with sodium acetate and acetic anhydride, forming aceto-coumaric acid, 
which decomposes into acetic acid and coumarin. 

The author has found that an aqueous solution of coumarin, unlike 
vanillin, forms a precipitate when iodine in potassium iodide is added in 
excess, the precipitate being at first brown and fiocculent, afterwards, 
on shaking, clotting together to form a dark-green, curdy mass, leaving 
the liquid perfectly clear. 

U. S. Standards. — Vanilla extract is the flavoring extract prepared 
from the vanilla bean, with or without sugar or glycerin, and contains in 
100 cc. the soluble matters from not less than 10 grams of the vanilla bean. 

Vanilla bean is the dried, cured fruit of Vanilla planifolia Andrews. 

Tonka extract is the flavoring extract prepared from tonka bean, with 
or without sugar or glycerin, and contains not less than 0.1% by weight 
of coumarin extracted from the tonka bean, together with a correspond- 
ing proportion of the other soluble matters thereof. 

Tonka bean is the seed of Coumarouna odorata Aublet {Dipteryx 
odorata (Aubl.) Willd.). 

The Adulteration of Vanilla Extract consists chiefly in the use of 
coumarin or extract of the Tonka bean, and in the substitution of artifi- 
cial vanillin, either alone or with coumarin, for the true extractives of 
the vanilla bean. Imitation vanilla flavors more often consist of a 
mixture of either tincture of Tonka or coumarin with vanillin in weak 
alcohol, colored with caramel, or occasionally with coal-tar colors. Or 
the exhausted marc from high-grade vanilla extract is macerated 
with hot water and extracted, the extract being reinforced with 
artificial vanillin or coumarin, or both. A pure vanilla extract possesses: 



854 FOOD INSPECTION AND ANALYSIS. 

certain peculiarities with regard to its resins and gums that distinguish 
it from the artificial, or indicate whether or not it has been tampered 
with. While it is possible to introduce artificial resinous matter in the 
adulterated brands with a view to deceiving the analyst, it is almost 
impossible to do this without detection, since different reactions are 
readily apparent in this case from those of the pure extracts. 

Prune juice is said to be used to give body and flavor to vanill? 
extract. The writer has found spirit of myrcia or bay rum in a sampk 
of alleged vanilla extract, containing also vanillin and coumarin. The 
adulterant in this sample was present to such an extent as to be unmis- 
takable by reason of the odor. 

Factitious Vanilla Extracts arc ordinarily indicated (i) by the presence 
of coumarin, (2) by the peculiar reactions of the resinous matter, or by 
the entire absence of these resins, (3) by the scanty precipitate with lead 
acetate, and (4) by the abnormally low or high content of vanillin. 

The following figures show the content of vanillin and coumarin in 
a few typical cheap " vanilla " extracts, selected from a large number 
examined by the author. All of these were entirely artificial, and ranged 
from 5 to 20 per cent by weight of alcohol. 

Vanillin, Coumarin, 

Per Cent. Per Cent. 

A 0.040 0.074 

B None 0.172 

C None 0-330 

D 0-250 None 

E., 0.025 0.144 

As a rule these cheap artificial preparations possess considerable body 
and flavor, but the latter is of a much grosser nature than the genuine 
vanilla extract, with the delicate and refined flavor of which they are not 
to be mistaken by any one at all familiar with both varieties. 

Winton and Bailey* have found as high as 2.55% of vanillin in 
imitation extracts. They also have detected the presence of acctanihde 
in amounts varying up to 0.15%. This substance at one time was 
extensively employed as an adulterant of vanillin, hence its presence in 
imitation extracts prepared from such vanillin. It is not only worthless 
as a flavor, but is a menace to health. 

* Conn. Agric. Exp. Sta., Rep. 1905, p. 131. 



FL/iyORlNG EXTRACTS AND THEIR SUBSTITUTES. 855 

The author is inclined to place 0.05% of vanillin as a minimum 
for genuine vanilla extract properly prepared and makes a practice of 
classing as not of good standard quality those samples that fall below. 

METHODS OF ANALYSIS OF VANILLA EXTRACT 

Detection of Artificial Extracts. — The presence of coumarin or Tonka 
tincture to any appreciable extent in vanilla extract is usually recognizable 
by the odor, to one skilled in examining these flavors. The odor of cou- 
marin is more pimgent and penetrating than that of \'anillin, and in mix- 
tures is apt to predominate over the milder and more delicate odor of 
vanillin. 

Add normal acetate of lead solution to a suspected extract. The 
absence of a precipitate is conclusive evidence that it is artificial. If 
a precipitate is formed, much information may be gained by its character. 
A pure vanilla extract should yield with lead acetate a heavy precipitate, 
due to the various extractives. The precipitate should settle in a few 
minutes, leaving a clear, supernatant, partially decolorized liquid. If 
only a mere cloudiness is formed, this may be due to the caramel present, 
and in any event is suspicious. 

Examination oj the Resins. — Resin is present in vanilla beans to the 
extent of from 4 to 11 per cent, and the manufacturer of high-grade 
essences endeavors to extract as much as possible of this in his product. 
This he can do by the use of 50% alcohol, in which all the resin is readily 
soluble, or by employing less alcohol and relying on the use of alkali 
to dissolve it. A pure extract free from alkali should produce a precip- 
itate, when a portion of the original sample is diluted with twice its volume 
of water and shaken in a test-tube. 

When, moreover, the alcohol is removed from such an extract, the 
excess of resin is naturally precipitated. 

The character of the resins extracted from the vanilla bean is so dif- 
ferent from that of other resins as to furnish conclusive tests, worked 
out by Hess * as follows: 25 to 50 cc. of the extract are de-alcoholized by 
heating in an evaporating-dish on the water-bath to about one-third its 
volume. Make up to the original volume with water, and, if no alkali 
has been used in the manufacture of the preparation, the resin will be in 
the form of a brown, flocculent precipitate. To entirely set free the resin, 
acidify, after cooling, with dilute hydrochloric acid, and allow to stand 
till all the resin has settled out, leaving a clear supernatant liquid. The 
resin may be quantitatively determined, if desired, by filtering, wash- 



* Jour. Am. Chcm. Soc, 21 (1899), p. 721, 



856 FOOD INSPECTION AND ANALYSIS. 

ing, diying, and weighing, but in this case should stand for a long time 
before filtering. 

The resin is collected on a filter, washed, and subjected to various 
tests. A piece of the filter with the attached resin is placed in a beaker, 
containing dilute potassium hydroxide. Pure vanilla resin dissolves 
to a deep-red color, and is reprecipitated on acidifying with hydrochloric 
acid. Dissolve another portion of the precipitate in alcohol, and divids 
the alcoholic solution into two portions, to one of which add a few drops 
of ferric chloride, and to the other hydrochloric acid. Pure vanilla resin 
shows no marked coloration in either case, but foreign resins nearly all 
give color reactions under these conditions. 

Tannin. — Test a portion of the filtrate from the resin for tannin by 
the addition of a few drops of a solution of gelatin. A small quantity 
of tannin only should be indicated, if the extract is pure, a large excess 
tending to show added tannin. 

Determination of Vanillin. — Vanillin may be determined (i) colorimet- 
rically, or (2) by extraction and weighing. The former is by far the 
quicker and more economical method, since it may be carried out 
directly in a very small portion of the original alcoholic extract. When,, 
as in some instances, the analyst has only one small bottle of vanilla 
extract for analysis, it becomes a matter of importance to use as little 
as possible for each determination. The determination of vanillin by 
both methods should give concordant results. 

Colorimetric Method.^ — This is carried out in the author's lab- 
orator)' as follows: 2 cc. of the vanilla extract are measured into a test- 
tube, and sufficient lead hydrate is added to completely decolorize it. The 
mixture is washed upon a filter, and filtrate and washings are collected 
in a Nessler tube. Bromine water is then added, after which enough 
of a freshly prepared 10% ferrous sulphate solution is added to get the 
maximum bluish-green color that will be produced, if vanillin is present. 
A standard vanillin solution is freshly prepared by dissolving 50 mgm. 
of pure vanillin in 25 cc. of alcohol, and making up to 100 cc. with water. 
A series of color standards is then made, taking, for instance, |, i, i^, 2, 
2^, 3, etc., cc. of the vanillin solution in 50 cc. Nessler tubes, each being 
treated with two or three drops of bromine water, and with the ferrous, 
sulphate solution, and made up to the 50-cc. mark. 

The lead hydrate is prepared by dissolving 200 grams of lead acetate 
in 850 cc. of water. The solution is filtered, a solution of potassium. 

* Massachusetts State Board of Health, An. Rep., 1899, p. 629. 



FLAl^ORING EXTRACTS AND THEIR SUBSTITUTES. 



S57 



hydroxide is added in excess, and the precipitated hydrate is washed 
thoroughly several times by decantation, or until neutral. Keep an excess 
of water in the reagent bottle, and shake up to form a heavy, white emul- 
sion before adding to decolorize. Unless the lead hydrate is washed 
free from alkali, the latter will precipitate the iron salt when added. 

If, for example, 2 cc. of a sample extract, treated as above, are found 
to give a color corresponding in depth to that produced by 5.5 cc. of the 
standard solution, the percentage of vanillin would be thus calculated: 
100 cc. standard solution contain 0.050 gram vanillin. 
I cc. " " " 0-0005 " 

5-5 cc. " " " 0.00275 " 

Since 2 cc. of the sample are equivalent to 5.5 cc. of the standard 
solution, it follows that 

2 cc. of sample contain 0.0275 gra^^i vanillin. 
.-. 100 cc. " " " 0.1375 " 

In order to avoid calculation of each determination when a large 
number of extracts have to be examined, the following table will be found 
useful for expressing results, where the above method of procedure has 
been exactly carried out : 

Number of Cubic Centi- 
meters of Standard 
Vanillin Solution * 
Corresponding 
Sample. 

,25 0.00625 

5 0.0125 

75 0.01875 

0.025 

5 0-0375 

0.05 

,5 0.0625 

0.075 



to 2 cc. 01 

o 

O 

o 
I 
I 

2 
2 

3 

3 
4 
4 
5 
5 
6 

7 
8 

9 

10 



Equivalent 
Per Cent of 

Vanillin 
in Sample. 



0-0875 
O.I 

O.II25 
0.125 

0.1375 
0.15 

0.175 
0.2 
0.225 
0-25 



* 0.05 gram vanillin in lOO cc. 



S58 FOOD INSPr.CTION /1Nl> ANALYSIS. 

Determination of Vanillin, Coumarin, and Acetanilide.— //c5.? and 

I'lrsio// Mctliod, Modijird by Win/on and Pxiilcy^- Weigh 25 grams of ihc 
cxlracl inio ;i joo-cc. l)cakcr willi marks showing volumes of 25 and 
50 c-c. Dilute to the 50 ce. mark, and eva|)orate in a water-bath to 25 cc. 
al a temperature in the bath of not more than 70° C. Dilute i\. second 
time lo 50 cr. and cvaporalc to 25 cc. Add normal lead acetate solution 
drop by drop unlil no more |)recipitate forms. Slir with a glass rod 
lo facilitate lloeeulation of the precii)itale, filter through a moistened 
("liter, and wash three limes with hot water, taking care that the total 
filtrate does not measure more than 50 cc. Cool the filtrate, and shake 
with 20 cc. of ether in a sejjaratory funnel. Remove the ether to another 
.separatory funnel, and repeat the shaking of the af|ueous licpiid with 
ether three limes, using 15 cc. each time. Shake the combined ether 
.solutions four or five times with 2''/,, ammonium hydroxide, using to 
cc. for the first shaking, and 5 vv. for each subsef|uent shals^ing. 
I\e-(r\e llie C()iti|)ine(| ammoiiiacal solutions for determination of vanillin. 

Wash tlie ether solution into a weiglied dish, and allow the ether to 
evaporate al the nxmi lemjK-ralure. Dry in a desiccator, and weigh. 
Stir the residue for fifteen minutes with 15; cc. of ])elroleum ether (boiling 
point ^^o tt) 40" C.) and decant the clear liipiid into a beiiker. Repeat 
the extraction with petroleum ciher two or three limes. Jf the residue 
is completely dissolved by this IreatmenI, the absence of acetanilide and 
other impurities in the coumarin is assured. Should an ap|)reciable 
amount of material remain undissolved, allow the dish and contents to 
stand in the air until apparently dry, completing the drying in a desiccator. 
Weigh, and deduct the weight from the weight of tiie residue obtained 
after the ether evaporation, thus obtaining the weight of tin- coumarin. 
The petroK'um ether resiflue, if acetanilide, should melt at about 112° C. 
and resiK)n(l to Ritserl's lest (p. ?>'^q). 

Allow the iH-troleum ether extract to evaporate al room (emi)erature. 
If it is |)ure coumarin, it should have a melting-point within a few degrees 
of 67° C. and respond to the author's test (p. 859). 

Slightly acidulate the ammoniacal solution reserved for vanillin with 
10% hydrochloric acid. Cool, and shake out in a separatory funnel 
with four ])ortions of elher, as describi-d for the first ether extraction. 
Evaporate the elher at room tem|)eralure in a weighed dish, dry over 
suli)huric acid, and weigii. 

* Jour. Am. Ciicm. Six ., n, iSgij, p. 256.; 24, ii>02, p. 1128; 27, 1905, p. 719. 



I-I.A^ORINC, HXTR/tCrs AND THIIIK SUHSIirilTliS. 859 

If iicotanilidc lias not been |)rcvi()iisly (Ictcctcd, lliis residue shoulfl 
he pure vanillin witli a meltinf^-|K)inl within a few degrees of 80° C. 

If acetanilide has been detected, dissolve the residue in r^ cc. of 10% 
ammonium hydroxide, and shake twice with an equal volume of ether. 
Kvaporate the ether solutif)n at room temj)erature, dry in a rlesircator, 
and weigh. Dcfhut this weiglit from the previous weighl, ihus obtain- 
ing the weight of pure vanilHn. The total weight of the acetanilide is 
obtained by ad(h'ng llic weight of this last extract to that of the resichic 
previously obtained and identified as acetanilide. 

In doubtful cases the ammoniacal solution should be acichTied, shaken 
out with ether, and the melting-jjoint of the vanillin, obtainerl by evaj)- 
oration at room tem])erature, determined. 

In case the colorimetric method for v;miihn was used, and (oumarin 
only is to be .separated for gravimetric determination, the author has 
found that good results are usually obtained by simply treating the de- 
alcoholized original sample with ammonia, extracting it with 3 or 4 
portions of chloroform in a .separatory funnel, and evaporating the com- 
bined chloroform extrad in a tared dish at a temperature not exreecjing 
60''-' in the oven. 

Many of the |)re(autions employed in carrying cnit the abc;ve processes 
for vanillin and coumarin determination may be dispensed with, if the.se 
substances are simi)ly to be tested for qualitatively. 

Leach's Test for Coumarin. — The residue, h)elieved to be coumarin, 
obtained as de.scriberl in the |)receding section, is identified by the follow- 
ing test: Add a few drops of water, warm gently, and add to the solu- 
tion a httle iodine in potassium ioflide, reagent No. 143. In [presence 
of coumarin a brown precijjitate will form, which, on stirring with the 
rod, will soon gather in dark-green flecks. The reaction is especially 
marked if done on a white plate or tile. 

Ritsert's Tests for Acetanilide.* — Boil the acetanilide, obtained as 
describ<fl on page 858, in a .small beaker for two or three minutes with 
2 to 3 cc, of concentratefl hydrochloric acid, cool, divifle into three [)or- 
lions, and te.st in .small tubes (4 to 5 mm. inside fliameter), or by sj)Otting 
on a j)orcelain plate, as follows: 

(i) To one portion add carefully i to 3 drops of a. solution of chlorinated 
lime (1:200; in such a manner that the two .scjlutions do not mix. A 
beautiful blue color formed at the juncture of the two liquids indicates 

acetanilirlc. 

♦Pharm. Ztg., 33, 1888, p. 383; AliS. Zoits. anal. Chcm., 27, 1888, p. 667. 



86o FOOD INSPECTION /IND ANALYSIS. 

(2) To another portion add a small drop of potassium permanganate 
solution. A clear green color is formed if any appreciable amount of 
acetanilifle is present. 

(3) Mix the tliird jjortion with a small drop of 3% chromic acid 
solution. Acetanilide gives a yellow-green solution, changing to dark 
green on standing five minutes, and forming a dark blue precipitate 
on addition of a drop of caustic potash solution. 

These tests are conclusive only when taken in conjunction with the 
melting-point. 

Vanillin and Coumarin Crystals Under the Microscope. — These sub- 
siances are best examined when crystallized from ether solution, and 
several crystallizations may be found necessary, before the best results 
are obtained. For examination, pour a few drops of the ether solution 
of the purified vanillin or coumarin directly on a slide, and allow to 
evaporate spontaneously. Under best conditions vanillin crystallizes 
from ether in long, slender needles, often radiating from central points, 
or forming, star-shaped bundles. 

Coumarin crystals are shorter and thicker than vanillin. 

With polarized light pure vanillin crystals give a brilliant play of 
colors between crossed nicols, even without the selenite plate, while pure 
coumarin crystals without the selenite are almost lacking in var}'ing 
colors, and show very little play, even when the selenite is employed. 
This sharp distinction is not true, when crystallized from chloroform. 

Determination of Glycerin. — The presence of any considerable quantity 
of glycerin is apparent by the character of the residue obtained on evaporat- 
ing 5 grams to dryness, in the determination of total sohds. The 
residue, if glycerin is present in notable amount, appears of a moist 
consistency, even when a practically constant weight has been attained 
at 100° C. 

To determine glycerin, proceed as with wines (p. 703). 

Determination of Alcohol. — Measure out 25 cc. of the sample, dilute 
to 50 cc. with water, and distil off about 20 cc. in a 25-cc. graduated 
receiver. Make up to the mark with water, determine the specific gravity 
at 15.6°, and find from the alcohol table the per cent corresponding. 

Cane Sugar and Glucose are determined as in the case of preserves 
and jellies. 

Detection of Caramel. — Lead Acetate Method. — Dealcoholize, precipi- 
tate with lead acetate, and filter, as described for the determination of 
vanillin, coumarin, and acetanilide (page 858). If the extract is pure, 



FLAI^ORING EXTRACTS AND THEIR SUBSTITUTES. 86r 

the filtrate will be light yellow; if colored with caramel, the filtrate will 
be yellow-brown or deep brown, according to the amount present. 

Color Quotient. — Method of Woodman and Newhall* — Evaporate 
35 cc. of the sample, or, if necessary, a diluted portion of the 
sample, on the water-bath to one-third its volume, and replace the 
loss by addition of water. Shake the dealcoholized extract in a 
separatory funnel with three successive portions of 15 cc. each of ethyl 
acetate. After the last portion has been separated, reserve part of the 
aqueous layer for comparison, and shake 30 cc, or as much as possible 
of the remainder with 15 grams of fuller's earth, allow to stand for half 
an hour and filter. The percentage of color removed by ethyl acetate, 
divided by the percentage of color removed by fuller's earth, gives the 
'■ color quotient." For example, a standard extract gave a color quotient 
of 2.30, whereas a caramel solution gave 0.276. 

Coal-tar Colors are detected by the usual tests (pp. 793 to 812). 

LEMON EXTRACTS. 

Spirit or essence of lemon of the National Formulary and former 
editions of the Pharmacopoeia, is a 5% solution (by volume) of lemon 
oil in deodorized alcohol, colored with lemon peel. 

This preparation was dropped from the 8th revision of the Phar- 
macopoeia, and Tinctura limonis corticis or tincture of lemon peel added. 
The following are the directions for the preparation of the latter: 

"Lemon peel, from the fresh fruit, in thin shavings and 

cut in narrow shreds 500 grams 

"Alcohol, a sufficient quantity to make 1000 cc. 

" Macerate the lemon peel in a stoppered, wide-mouthed container, 
in a moderately warm place, with 1000 cc. of alcohol during forty-eight 
hours, with frequent agitation; then filter through purified cotton, and, 
when the hquor has drained off completely, gradually pour on enough 
alcohol to make 1000 cc. of tincture, and filter." 

U. S. Standards. — Lemon Extract is the flavoring extract prepared 
from oil of lemon, or from lemon peel, or both, and contains not less 
than 5% by volume of oil of lemon. 

Oil of Lemon is the volatile oil obtained, by expression or alcoholic 
solution, from the fresh peel of the lemon {Citrus limonum L.), has an 



*Tech. Quar., 21, 1908, p. 280. 



862 FOOD INSPECTION AND'.ANALYSIS. 

optical rotation (25° C.) of not less than +60° in a loo-mm. tube, and 
contains not less than 4% by weight of citral. 

Terpendess Extract of Lemon is the flavoring extract prepared by 
shaking oil of lemon with dilute alcohol, or by dissolving terpeneless oil 
of lemon in dilute alcohol, and contains not less than 0.2% by weight 
of citral derived from oil of lemon. 

Terpeneless Oil of Lemon is oil of lemon from which all or nearly 
all of the terpenes have been removed. 

The U. S. standard for lemon extract (5% of lemon oil by volume) 
is a fair one. In fact there are commercial extracts on the market 
containing as high as 12%. An extract of lemon to contain 5% of 
lemon oil must contain at least 80% by volume of alcohol, lemon oil 
being insoluble in dilute alcohol. Deodorized, or purified alcohol, com- 
monly known as cologne spirits or perfumers' alcohol, is used in the 
highest-grade preparations, since the odor of ordinary commercial alcohol 
produces a slightly deleterious effect. 

Adulteration of Lemon Extracts. — For making a cheap extract the 
cost of the lemon oil is not so important an item as that of the alcohol, 
and as little as possible of the latter is employed, though pure oil 
is doubtless used. These terpeneless extracts are made by rubbing 
the oil in carbonate of magnesia in a mortar, stirring in slowly a 
little strong alcohol, and allowing the mixture to soak for some 
time. A varying amount of water is added a little at a time, and 
the whole is shaken and again allowed to stand, sometimes for a week, 
before filtering. Finally the extract is filtered, and the coloring matter 
added, consisting sometimes of turmeric tincture and sometimes of coal- 
tar dyes. In these cheap extracts the per cent of alcohol often runs 
below 40, and as little as 4.5% by volume of alcohol has been found 
by the author in a commercial extract. With less than 45% of alcohol 
by volume, no appreciable amount of oil is dissolved, only a portion 
of citral, though such preparations are sometimes bottled as " pure 
extract of lemon." Time and again manufacturers have protested to 
the author that the purest oil w^as used by them, when notified that their 
brand contained no oil, or when prosecuted in court, and were with 
difficulty convinced that the trouble with their goods was that, on account 
of weak alcohol employed, the lemon oil used failed to get into the final 
product. It is true that a certain taste or odor of the lemon is present, 
even in cheap varieties wherein no oil is found, due to the fact that 
cvea dilute alcohol, when slowly percolating through the magnesia in 



FLAyORlNG EXTR/1CTS AND THEIR SUBSTITUTES. 86 j 

which the oil is finely distributed, does abstract therefrom a certain 
amount of citral, which is, however, but a mere shadow of the sub- 
stance and body possessed by a strong alcoholic solution of oil of 
lemon. 

In many instances, where formulas appear stating the name and 
per cent of ingredients, these formulas are entirely deceptive and mis- 
leading, in that the statements are not borne out on analysis. 

The flavor of the cheap extracts is sometimes reinforced by the 
addition of such substances as citral, oil of citronella, and oil of lemon- 
grass, but minute quantities only of these pungent materials can be used, 
not exceeding 0.33% in the case of citral, and 0.1% in the case of the 
two last mentioned oils. Cane sugar and glycerin are sometimes 
found. 

U. S. P. tincture of lemon peel owes its color to natural substances 
extracted by the alcohol. This color, however, readily fades on exposure 
to light. Other coloring matters employed are largely coal-tar dyes, 
and occasionally tincture of turmeric or saffron. 

During 1901 practically all the brands of lemon extract sold in Massa- 
chusetts were collected and analyzed. 167 samples were examined, 
representing about 100 brands, and 139 samples were classed as adul- 
terated, based on 5% lemon oil as a standard, and depending on whether 
or not the contents conformed to the labels on the bottles. 

The typical analyses, given in tables on p. 864, are selected from the 
tabulated results of the above examination.* 

Forty-two samples contained no lemon oil, ranging in content of 
alcohol from 4 to 45 per cent. 



METHODS OF ANALYSIS OF LEMON EXTRACT. 

A. S. Mitchell was the earliest among food chemists to systematically 
examine lemon extract, and to him are due the methods for determin- 
ing oil of lemon, as wxll as various other tests now adopted provision- 
ally by the A. O. A. C.f 

Detection of Oil of Lemon. — If on adding a large excess of water 
to a little of the extract in a test-tube no cloudiness occurs, the oil may 

* An. Rep. Mass. State Board of Health, 1901, p. 459; Food and Drug Reprint, p. 41. 
t Jour. Am. Chem. Soc, 21, 1899, p. 1132; U. S. Dept. of Agric, Bur. of Chem., Bui. 
65, p. 73; Bui. 107 (rev.), p. 159. 



864 



FOOD INSPECTION /IND /IN A LYSIS 



LEMON EXTRACTS OF STANDARD QUALITY. 



Polarization 

in 2oo-mm. 

Tube. 


Lemon Oil, 

Per Cent by 

Volume. 


Specific 

Gravity at 

I5.&°C. 


Alcohol, 
Per Cent by 

Volume. 


Foreign Ingredients. 


30.8 
26.0 

23-5 
21.8 

20.0 

18.0 
17.0 


9-1 
7-6 
6.9 
6.4 
5-9 
5-3 
5-0 


0.8280 
0.8402 
0-8352 
0.8396 

0-8335 
0.8268 
0.8496 


84-39 
80.49 

81.74 
82.88 
84.24 
86.82 
80.06 


Turmeric 
Dinitrocresol 



INFERIOR OR ADULTERATED LEMON EXTRACTS. 





Polarization 


Lemon Oil, 


Specific 


Alcohol, 






in 200-mm. 


Per Cent by 


Gravity at 


Per Cent by 


Foreign Ingredients. 




Tube. 


Volume. 


15.6° C. 


Volume. 






14.0 


4-1 


0.8592 


77.62 


Dinitrocresol 




12.2 


3-6 


0.8644 


76 


08 


< ( 




II. 


3-1 


0.8620 


77 


50 


A coal-tar dye 




9-9 


2-9 


0.8615 


77 


90 






8.0 


2-3 


0.8531 


81 


61 


Dinitrocresol 




6.8 


2.0 


0.8416 


87 


55 


Tropaeolin 




5-0 


1-5 


0.8832 


71 


10 


' ' 




3-5 


I.O 


0.8939 


67 


68 






2.8 


0.8 


0-8995 ' 


65 


23 


Dinitrocresol 




2.2 


0.6 


0.8941 


67 


69 


" 




1.4 


0.4 


0.9136 


59 


40 


A nitro dye 




0-3 


0.1 


. 9408 


46 


40 


Dinitrocresol 




0.0 


0.0 


0-9937 


4 


49 


Tropaeolin 




-8.0 


0.0 








Invert sugar 




27.0 


CO 




27 


49 


Cane sugar 




0.0 


0.0 




47 


35 


Oil other than lemon 



fairly be inferred to be absent. The degree of cloudiness produced is 
proportional to the amount of lemon oil present. 

Determination of Lemon Oil. — MitcheWs Methods. — (i) By Polariza- 
tion. — Polarize the undiluted extract in a 200-mm. tube at 20° C. Divide 
the reading on the Ventzke cane sugar scale by 3.4, and if cane sugar 
or other optically active substances are absent, the quotient expresses 
the per cent of lemon oil by volume. With instruments reading in circular 
degrees, divide the rotation in minutes at 20° C. by 62.5. If the Laurent 
instrument with sugar-scale is used, divide the sugar-scale reading by 4.8. 

Cane sugar, though rarely found in lemon extract, is occasionally 
used in small amount. It is said to aid in the solution of the oil. If it 
is present, wash the solid residue from 10 cc. of the sample (dried on 
a water-bath) with three portions of 5 cc, each of ether, to remove waxy 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 865 

and fatty matters, dry and weigh the residue of cane sugar, deducting 
0.38 from the reading for each 0.1% of sugar so found. 

(2) By Precipitation. — Transfer by a pipette 20 cc. of the extract 
to a Babcock milk-flask, add i cc, of dilute hydrochloric acid (1:1); add 
25 to 28 cc. of water previously warmed to 60° C; mix, and stand in 
water at 60° for five minutes; whirl in a centrifuge for five minutes; fill 
with warm water to bring the oil into the graduated neck of the flask, 
and repeat the whirling for two minutes; stand in water at 60° for a few 
minutes, and read the per cent of oil by volume. Where the oil of lemon is 
present in amounts over 2%, add to the percentage of oil found 0.4% 
to correct for the oil retained in solution. Where less than 2% and more 
than 1% is present, add 0.3% for correction. 

Save the precipitated oil for the determination of refraction. 

When the extract is made in accordance with the U. S. Pharma- 
copoeia, the results by the two methods just given should agree within 
02%. 

To obtain per cent by weight from per cent by volume, as found 
by either of the above methods, multiply the volume percentage by 
0.86, and divide the result by the specific gravity of the original ex- 
tract. 

Howard's Modification of Mitchell's Precipitation Method."^ — Pipette 
10 cc. of the extract in a Babcock milk bottle, and add in the following 
order, 25 cc. of cold water, i cc. hydrochloric acid (specific gravity 1.2), 
and 0.5 cc, chloroform. Close the mouth of the bottle with the thumb, 
and shake vigorously for not less than one minute. Whirl the bottle 
in a centrifuge for one and one-half to two minutes, thus forcing the chloro- 
form and oil to the bottom of the bottle, and remove all but 3 or 4 cc, of 
the clear supernatant liquid by means of a glass tube of small bore 
connected with an aspirator. 

To the residue add i cc. of ether, agitate thoroughly, plunge the 
bottle to the neck in a boiling-water bath, holding at shght angle, and 
rotate in the bath for exactly one minute. This step is best carried out 
by removing one of the small rings from a water- or steam-bath and 
holding the bottle in the live steam. The ether serves the purpose 
of steadily and rapidly sweeping out every trace of chloroform with- 
out appreciable loss of oil. Finally, cool the bottle, fill nearly to 



* Jour. Am. Chem. Soc, 30, 1908, p. 608. 



866 FOOD INSPECTION AND ANALYSIS. 

the top of the neck with water at room temperature, centrifuge 
for one-half minute, read the column of separated oil to the top 
meniscus, and multiply the reading by two, thus obtaining the per 
cent of oil. 

This method may also be used for determining the oil in extracts 
of orange, peppermint, clove, cinnamon, and cassia, employing in the 
case of the heavier oils dilute sulphuric acid (1:2), instead of water, 
in filling the bottles before the last centrifuging. 

Determination of Alcohol. — Mitchell has shown that the difference 
in specific gravity between oil of lemon and stronger alcohol is not so 
great, but that a very close approximation to the true percentage of alcohol 
in lemon extracts may be obtained from the specific gravity itself, assum- 
ing, of course, that foreign substances, such as sugar, glycerin, etc., are 
absent. In the absence of such foreign substances determine the specific 
gravity of the sample, ascertain from the alcohol tables on pages 661- 
664, the per cent of alcohol by volume corresponding. This gross figure 
includes the lemon oil, the per cent of which should be deducted for 
the correct per cent of alcohol. 

In the absence of oil of lemon, a measured portion of the original 
sample may be distilled, and the percentage of alcohol determined from 
the distillate in the usual manner, but when lemon oil is present, this 
should first be removed by diluting 50 cc. of the extract with water 
to 200 cc. exclusive of the oil in the sample, and shaking the mixture 
with 5 grams of magnesium carbonate in a flask, filtering through 
a dry filter, and determining the alcohol by distillation in a por- 
tion of the filtrate. The result is multiplied by 4 to correct for the 
dilution. 

Determination of Citral. — Chace's Method.'^ — i. Reagents. — (a) Alde- 
hyde-free Alcohol. — Allow alcohol (95% by volume) containing 5 grams 
of metaphenylene diamine hydrochloride per liter to stand for twenty- 
four hours with frequent shaking. Nothing is gained by previous treat- 
ment with potassium hydroxide. Boil under a reflux cooler for at least 
eight hours, longer if necessary, allow to stand over night and distil, 
rejecting the first 10 and the last 5 per cent which come over. Store in 
a dark, cool place in well-filled bottles. 25 cc. of this alcohol, on stand- 
ing for twenty-minutes in the cooling bath with the fuchsin solution 

* Jour. Am. Chem. Soc, 28, 1906, p. 1472. U. S. Dept. of Agric, Bur. of Chem., Bui. 
122, p. 32. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 867 

(20 cc), should develop only a faint pink coloration. If a stronger 
color is developed, treat again with metaphenylene diamine hydro- 
chloride. 

(b) Fuchsin Solution. — Dissolve 0.5 gram of fuchsin in 250 cc. of 
water, add an aqueous solution of sulphur dioxide containing 16 grams 
of the gas, and allow to stand until colorless, then make up to i liter 
with distilled water. This solution should stand twelve hours before 
using, and should be discarded after three days. 

(c) Standard Citral Solution. — Use i mg, of c. p. citral per cc. in 
50% by volume aldehyde-free alcohol. This solution deteriorates on 
standing, and should not be kept over three or four days. 

2. Apparatus. — {a) A Cooling Bath. — Keep at from 14 to 16° C. 
The aldehyde-free alcohol, fuchsin solution, and comparison tubes are 
to be kept in this bath. 

(&) Colorimeter. — Any form of colorimeter, using a large volume of 
solution and adapted to rapid manipulation, may be used. 

The comparison may also be made in Nessler or Hehner tubes. 

3. Manipulation. — Weigh in a stoppered weighing flask approxi- 
mately 25 grams of extract, transfer to a 50-cc. flask, and make up to 
the mark at room temperature with aldehyde-free alcohol. Measure at 
room temperature and transfer to a comparison tube 2 cc. of this solution. 
Add 25 cc. of the aldehyde-free alcohol (previously cooled in a bath), 
then 20 cc. of the fuchsin solution (also cooled), and finally make up to 
the 50-cc. mark with more aldehyde-free alcohol. Mix thoroughly, stopper, 
and place in the cooling bath for fifteen minutes. Prepare a standard 
for comparison at the same time and in the same manner, using 2 cc. of 
the standard citral solution. Remove and compare the colors developed. 
Calculate the amount of citral present and repeat the determination, 
using a quantity sufficient to give the sample approximately the strength 
of the standard. From this result calculate the amount of citral in the 
sample. If the comparisons are made in Nessler tubes, standards con- 
taining I, 1.5, 2, 2.5, 3, 3.5, and 4 mg. should be prepared, and the trial 
comparison made against these, the final comparison being made with 
standards between 1.5 and 2.5 mg., varying but 0.25 mg. 

It is absolutely essential to keep the reagents and comparison tubes 
at the required temperature. Comparisons should be made within one 
minute after removing the tubes from the bath. Where the comparisons 
are made in the bath (this being possible only where the bath is glass), 
the standards should be discarded within twenty-five minutes after 



868 FOOD INSPECTION AND /IN A LYSIS. 

adding the fuchsin solution. Give samples and standards identical 
treatment. 

Hiltnefs Method* — i. Reagents. — (a) Metaphenelene Diamine Hydro- 
chloride Solution. — Prepare a i% solution of metaphenelene diamine 
hydrochloride in 50% ethyl alcohol. Decolorize by shaking with fuller's 
earth or animal charcoal, and filter through a double filter. The solution 
should be bright and clear, free from suspended matter and practically 
colorless. It is well to prepare only enough solution for the day's work, 
as it darkens on standing. The color may be removed from old solutions 
by shaking again with fuller's earth. 

ih) Standard Citral Solution. — Dissolve 0.250 gram of c. p. citral 
in 50% ethyl alcohol and make up the solution to 250 cc. 

(f) Alcohol. — For the analysis of lemon extracts, 90 to 95 per cent 
alcohol should be used, but for terpeneless extracts alcohol of 40 to 50 
per cent strength is sufhcient. Filter to remove any suspended mat- 
ter. The alcohol need not be purified from aldehyde. If not prac- 
tically colorless, render sHghtly alkaline with sodium hydroxide and 
distil. 

2. Apparatus. — The Schreiner colorimeter (page 77) or Eggertz 
tubes may be used. With this latter apparatus, alcohol is added, small 
quantities at a time, to the stronger colored solution until after shaking 
and viewing transversely, the colors in the two tubes are exactly matched. 
Calculations are then made by estabHshing a proportion between the 
volumes of samples taken and the final dilutions. 

3. Manipulatiojt. — All of the operations may be carried on at room 
temperature. Weigh into a 50-cc. graduated flask 25 grams of the 
extract, and make up to the mark with alcohol (90-95 per cent). Stopper 
the flask and mix the contents thoroughly. Pipette into the colorimeter 
tube 2 cc. of this solution, add 10 cc. of metaphenylene diamine hydro- 
chloride reagent, and complete the volume to 50 cc. (or other standard 
volume) with alcohol. Compare at once the color with that of the 
standard, which should be prepared at the same time, using 2 cc. of 
standard citral solution and 10 cc. of the metaphenylene diamine reagent, 
and making up to standard volume with alcohol. From the result of 
this first determination, calculate the amount of standard citral solution 
that should be used in order to give approximately the same citral 
strength of the sample under examination, then repeat the determination, 

* A. O. A. C. Proc, 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 34. Jour, 
led. Eng. Chem., I, 1909. 



FLylVORING EXTRACTS AND THEIR SUBSTITUTES. 869 

Methyl Alcohol has been used by unscrupulous manufacturers in 
lemon extracts. It is detected and determined by the refractometer 
method of Leach and Lythgoe (page 749). 

As a confirmatory test for methyl alcohol the distillate, after testing 
by the Leach and Lythgoe method, may to advantage be subjected to 
the method of Mulliken and Scudder,* which depends on the conversion 
of the methyl alcohol to formaldehyde. The latter method is also useful 
as a rough preliminary test on the original extract without distillation, 
the extract, being, however, first diluted until the liquid contains approxi- 
mately 12% by weight of alcohol, shaking with magnesium carbonate, 
and filtering when lemon oil is present. 

Oxidize 10 cc. of the liquid in a test-tube as follows: Wind copper 
wire I mm. thick upon a rod or pencil 7 to 8 mm. thick, in such a manner 
as to inclose the fixed end of the wire, and to form a close coil 3 to 3.5 cm. 
long. Twist the two ends of the wire into a stem 20 cm. long, and bend 
the stem at right angles about 6 cm. from the free end, or so that the 
coil may be plunged to the bottom of a test-tube, preferably about 16 mm. 
wide and 16 cm. long. Heat the coil in the upper or oxidizing flame of 
a Bunsen burner to a red heat throughout. Plunge the heated coil to 
the bottom of the test-tube containing the diluted alcohol. Withdraw 
the coil after a second's time and dip it in water. Repeat the operation 
from three to five times, or until the film of copper oxide ceases to be 
reduced. Cool the liquid in the test-tube meanwhile by immersion in 
cold water. 

Test for Formaldehyde. — Divide the oxidized liquid in the test-tube 
into two parts, testing one for formaldehyde with pure milk by the 
hydrochloric acid and ferric chloride test. Test the other portion by 
Mulliken and Scudder's resorcin test for formaldehyde, page 820, avoid- 
ing an excess of the reagent.t 

Tests for Colors. — Evaporate a portion of the sample to dryness, 
dissolve the residue in water, and extract coal-tar colors if present by 
Arata's method, page 794, or with hydrochloric acid. 

Much information may often be gained by treatment of the original 
extract with strong hydrochloric acid. If the color employed be turmeric, 
no change in color will be evident on addition of the acid. If tropaeolin 
or methyl orange is present, the solution will turn pink, while partial 
decoloration of the solution indicates naphthol yellow S, and complete 
decoloration shows presence of dinitrocresols or naphthol yellow. 

* Am. Chem. Jour., 23, 1899, p. 266. t Ibid , 24, 1900, p. 451. 



870 FOOD INSPECTION AND ANALYSIS. 

Test for turmeric by boric acid, page 789. 

Determination of Total Solids and Ash. — Total Solids are estimated 
by evaporating on the water-bath 10 grams of the sample in a tared dish, 
and drying at 100° to constant weight. If glycerin be present, it is dif- 
ficult if not impossible to get a constant weight. Cane sugar and glycerin, 
if present, will be apparent in the residue. If capsicin has been used, 
it will be noticed by the taste. 

Burn to an ash the residue from the solids in a muffle at a low red 
heat, cool in a desiccator, and weigh. 

Glycerin is determined as in wine, page 703. 

Detection of Tartaric or Citric Acid. — To a portion of the extract 
in a test-tube add an equal volume of water to precipitate the oil. Filter 
and add one or two drops of the filtrate to a test-tube half full of cold, 
clear lime water. If tartaric acid is present, a precipitate will come 
down, which is soluble in an excess of ammonium chloride or acetic acid. 

Filter off the precipitate, or, if no precipitate is visible, heat the con- 
tents of the tube. Citric acid will precipitate in a large excess of hot 
lime water. 

Examination of Lemon Oil. — The oil separated from the extract in 
the process of determining the lemon oil by precipitation (p. 865), is 
most readily examined for its purity, after drying with calcium chloride, 
by determination of its specific gravity, its index of refraction, or its 
refractometric reading with the Zeiss butyro-refractometer, and its polari- 
scopic reading. 

The specific gravity and refractometric readings are determined as 
with fixed oils, using with the butyro-refractometer a sodium flame or 
yellow bichromate color-screen, which gives perfectly sharp readings 
without dispersion. 

The first table on page 871 shows readings on the Zeiss butyro- 
refractometer of pure lemon oil at various temperatures, using the 
sodium light. 

For examination of high polarizing essential oils like oil of lemon, 
the author employs a 50-mm. tube, in order to get readings on the 
undiluted oil well within the Hmits of the cane sugar scale on the polar- 
iscope. If such a tube is not available, dilute the oil with an equal 
volume of alcohol, and use the loo-mm. tube. The second table on 
page 871 expresses constants of pure lemon oils and of various com- 
monly employed adulterants, as determined in the laboratory of the 
Mascachusetts State Board of Health. 



CANNED AND BOTTLED VEGETABLES, ETC. 87) 

READINGS ON ZEISS BUTYRO-REFRACTOMETER OF LEMON OIL. 



Tempera- 


Scale 


Tempera- 


Scale 


Tempera- 




Tempera- 


Scale 


ture. 
Centigrade. 


Reading. 

i 


ture, 
Centigrade. 


Reading. 


ture, 
Centigrade. 


Reading. 


ture, 
Centigrade. 


Reading. 


40.0 


59-4 


35-0 


62.8 


30.0 


66.3 


25.0 


69.7 


39-5 


59-7 


34-5 


63.1 


29-5 


66 


6 


24-5 


70.0 


39-0 


60.1 


34-0 


63-5 


29.0 


67 





24.0 


70.4 


38-5 


60.4 


33-5 


63.8 


28.5 


67 


3 


23-5 


70.7 


38.0 


60.8 


Z^,-'^ 


64.2 


28.0 


67 


7 


23.0 


71.1 


37-5 


61.0 


32.5 


64.5 


27-5 


68 





22-5 


71.4 


37-0 


61.5 


32.0 


64.9 


27.0 


68 


4 


22.0 


71.8 


36.S 


61.8 


z-^-s 


6,-. I 


26.5 


68 


7 


21-5 


72.1 


36.0 


62.1 


31.0 


65.6 


26.0 


69 





21.0 


72-5 


35-5 


62.4 


30-5 


6^-9 


25-5 


69 


3 


20.5 


72.8 


35-0 


62.8 


30.0 


66.3 


25.0 


69 


7 


20.0 


73-2 



CONSTANTS OF SOME ESSENTIAL OILS. 



Oil. 



Butyro-refractometer 
(Sodium Light) at — 



Temp. 



Reading. 



Rotation 
in 100- 
Millimeter 
Tube , 

Ventzke 
Scale. 



Specific 

Gravity 

at 15.0° C. 



Oil of lemon (lowest) 

" " " (highest) , 

" " " grass (A, Giese) 

" " citronella (A. Giese) , 

Terpeneless oil of lemon (Hansel's) 

" <« <« << grass (Hansel's). 

Citral (A. Giese) 



25- 

25- 

22.5 

22.5 

23- 

23- 

22.5 



69-5 
71-2 
96.9 
87.1 
87-9 
91.0 
95-0 



173-0 

184.5 

-10.8 

— 10.2 

— 22.0 

-5-6 

-3-6 



0.8580 
0.8610 
0.9309 

0-9437 
0-9463 
0.9232 
0.9296 



Oil of Lemon is a light-yellow liquid, having the pleasant odor of 
fresh lemons, and an aromatiq, mild, somewhat bitter after taste. It 
is obtained from the grated rind of the lemon either by treatment with 
hot water, skimming off the oil which rises to the surface, or by pressure, 
or by distillation with water. It is rapidly changed by action of air and 
light, becoming "terpeney," and under these conditions its solubility 
in alcohol seems to increase. Its composition is somewhat uncertain, 
but according to Wallach * nearly 90% consists of hydrocarbons, mostly 
terpenes, the most important of which is the terpene limonenc f of the 
dextro-gyrate variety, also known as citrene. 

x\nother important constituent of lemon oil is the aldehyde citral. 



* Liebig's .^nnalen, 227, p. 290. 

t There are two limonenes, one of which is dextro- and the other laevo-rotary. The 
two are completely alike in their behavior, differing only in their optical rotation. 



872 FOOD INSPECTION AND ANALYSIS. 

present to the extent of from 7 to 10 per cent. To this the odor of the 
oil is largely due. A second aldehyde, citronellal, is also present. 

A frequent adulterant of lemon oil is turpentine oil, which lowers 
the rotation considerably, and is thus most easily rendered apparent. 

Chace * detects small quantities of turpentine by the difference in 
crystalline form of pinene nitroso chloride from that of limonene nitroso 
chloride. 

Citral (CioH,gO) is an aldehyde present in lemon oil and in oil of 
lemon-grass, and, while it may be separated from these oils, is prepared 
artificially by oxidizing geraniol with chromic acid.f It is a mobile oil, and 
when perfectly pure is optically inactive. The commercial citral is, 
however, slightly laevo-rotary, due no doubt to impurities. 

Oil of Lemon-grass is distilled from lemon-grass, Andropogon citratus 
(D. C), cultivated in India. It is reddish yellow in color, and has an 
intense lemon-like odor and taste. Very little is known of its composi- 
tion, but it seems to contain several aldehydes, one of which is citro- 
nellal, and another chral. The latter, however, is its chief constituent, 
being present to the extent of 70 to 75 per cent. 

Citronellal (CioHigO) is an aldehyde found in various oils, especially 
in citronella oil, from which it is readily separated. It is made artifi.cially 
by the oxidation of the primary alcohol citronellol (C10H20O). It is 
quite strongly dextro-rotary. 

Oil of Citronella is distilled from the grass Andropogon nardus (L.), 
growing chiefly in Ceylon, India, and tropical East Africa. It is a yel- 
lowish-brown liquid with a pleasant and lasting odor. Citronellal is 
present in this oil to the extent of from 10 to 20 per cent, and the oil 
contains also from 10 to 15 per cent of terpenes, among which are 

camphene. 

Tests for Citral, Citronellal, and Limonene. |— Shake 2 cc. of the 
sample to be examined in a corked test-tube with 5 cc. of a solution of 
10 grams of mercuric sulphate in sufficient 25% sulphuric acid to make 
100 cc. Citral yields a bright-red color, which rapidly disappears, 
leaving a whitish compound, which floats on top. Citronellal forms a 
bright-yellow color, renic ining for some time. Limonene forms an 
evanescent, faint flesh color, and leaves a white compound. 



* Jour. Am. Chem. Soc, 30, 1908, p. i475- 

t Ticmann, Berichte, 31, p. 3311. 

X Burgess, Chem. and Drugg., 57, p. 732. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 873 

ORANGE EXTRACT. 

Orange Oil is a yellowish liquid, having the characteristic odor of 
orange, and a mild aromatic taste. It is prepared from orange peel in 
an analogous manner to that of lemon oil, which it somewhat resembles 
in chemical composition. At least 90% of orange oil, according to 
Walach, consists of dextro-limonene (citrene). It has a much higher 
specific rotatory power than lemon oil. 

U. S. Standards. — Oil of Orange is the volatile oil obtained, by 
expression or alcoholic solution, from the fresh peel of the orange {Citrus 
aurantium L.) and has an optical rotation at 25° C. of not less than 
+ 95° in a loo-mm. tube. 

Terpeneless Oil of Orange is oil of orange from which all or nearly 
all of the terpenes have been removed. 

Orange Extract is the flavoring extract prepared from oil of orange, 
or from orange peel, or both, and contains not less than 5% by volume 
of oil of orange. 

Terpeneless Extract of Orange is the flavoring extract prepared by 
shaking oil of orange with dilute alcohol, or by dissolving terpeneless 
oil of orange in dilute alcohol, and corresponds in flavoring strength 
to orange extract. 

Analysis of Orange Extract. — The methods described under lemon 
extract (pp. 863 to 872) are also adapted for the analysis of orange extract. 

In the determination of orange oil by Mitchell's polariscopic method 
divide the direct reading on the Ventzke scale, calculated for the 200- mm. 
tube, by 5.3 to obtain the per cent of orange oil by volume. To obtain 
the per cent by weight, multiply the per cent by volume by 0.85 and 
divide by the specific gravity of the extract. 

ALMOND EXTRACT. 

Oil of Bitter Almonds is obtained by distilling crushed bitter almonds, 
peach seeds, or apricot seeds with water. It should be remembered that 
both sweet and bitter almonds yield a bland fixed oil on pressure, which is 
not to be confounded with the volatile oil yielded on distillation of the bitter 
almonds after the fixed oil has been pressed out. Bitter almonds contain 
a glucoside, amygdalin, together with a ferment known as emulsin or 
synaptase, which, acting on the amygdalin in the distillation, produces 
benzaldehyde and hydrocyanic acid as follows: 



874 toOD INSPECTION AND ANALYSIS. 

C20H27NO11 + 2H2O - C^H^O + HCN f 2C6H,206. 

Amygdalin Benzalde- Hydro- Glucose 

hyde cyanic acid 

The unpurified oil of bitter almonds consists largely of benzaldehyde, 
with a small amount of the poisonous hydrocyanic acid. Nearly all 
of the commerical oil is made from the cheaper apricot and peach seeds 
rather than those of the bitter almond, but the product is practically 
identical. The oil is freed from hydrocyanic acid by agitating with 
calcium hydrate and a solution of ferrous chloride, distilling the mixture, 
and drying the oil which comes over with calcium chloride. 

Benzaldehyde constitutes 90 to 95 per cent of oil of bitter almonds, 
having a bitter, acrid, burning taste, and a marked almond odor. The 
specific gravity of the crude oil varies from 1.052 to 1.082, while that 
of the purified oil (benzaldehyde) at 20° is 1.0455. ^^s boiling-point is 
180° C. On standing it becomes readily oxidizable to benzoic acid. It 
is readily soluble in alcohol and ether. Its solubility in water is slight, 
1:300. Its index of refraction at 20° C. is 1.5446. It should be noted 
that the refractive indices of almond oil, whether with or without hydro- 
cyanic acid, and of artificial benzaldehyde are nearly the same, 

Benzaldehyde is produced artificially in a variety of ways, but is 
chiefly prepared by the action of chlorine on hot toluene. The result- 
ing benzyl chloride is distilled with lead nitrate and water in an atmos- 
phere of carbon dioxide, which forms benzoic aldehyde. Synthetic 
benzaldehyde has the same properties as the purified oil of bitter almonds, 
and has largely displaced it in the market, not the least of its advantages 
being its freedom from hydrocyanic acid. 

Almond Extract, — Essence of bitter almonds, or Spiritus amygdala 
amarcB, is thus prepared according to the U. S, Pharmacopoeia: 

Oil of bitter almonds 10 cc. 

Alcohol , , 800 cc. 

Distilled water sufficient to make 1000 cc. 

Thus 1% of almond oil is present in the product. 

U. S. Standards. — Oil of Bitter Almonds, commercial, is the volatile 
oil obtained from the seed of the bitter almond {Amygdalus communis 
L.), the apricot {Primus armeniaca L.), or the peach {Amygdalus per ska 
L.). 

Almond Extract is the flavoring extract prepared from oil of bitter 



FLOyORING EXTRACTS AND THEIR SUBSTITUTES. 875 

almonds, free from hydrocyanic acid, and contains not less than 1% 
by volume of oil of bitter almonds. 

Adulteration of Almond Oil. — The official essence of the Pharma- 
copoeia does not specify that the almond oil used be perfectly free from 
hydrocyanic acid, in spite of the fact that its highly poisonous nature is 
well known, and that it exists in the crude oil to the extent of from 4 to 
6 per cent. True, but httle of it is found in the extract, but in these days, 
when the unannounced presence in foods of such substances as antiseptics 
and coloring matters is regarded as questionable from a sanitary stand- 
point, in spite of the fact that their toxic effects on man are still matters 
of controversy, there thould be little hesitancy in pronouncing the presence 
of prussic acid objectionable, especially when a pure almond oil entirely 
free from it is readily obtainable. 

The presence of nitrobenzol or oil of mirbane as a substitute of 
almond oil is to be looked for. This substance is sometimes, though 
incorrectly, called artificial oil of bitter almonds. It is a heavy, yellow 
liquid of the composition CgHgNOs, readily soluble in water. Its specific 
gravity at 20° C. is 1.2039. Its boiling-point is 205° C. It is formed 
by the action of nitric acid on benzol. It possesses a highly pungent 
odor, somewhat like that of oil of bitter almonds, though more penetrating 
and less refined. Its index of refraction at 20° C. is 1.55 17. 

METHODS OF ANALYSIS OF ALMOND EXTRACT. 

Determination of Benzaldehyde. — Hortvet and Wesfs Method.^ — 
Measure 10 cc. of the extract into a loo-cc. tlask, add 10 cc. of a 10% 
sodium hydroxide solution, and 20 cc. of a 3% hydrogen peroxide solution, 
cover with a watch-glass and place on a water-oven. Oxidation begins 
almost immediately and should be continued from five to ten minutes 
after all odor of benzaldehyde has disappeared, which usually requires 
from twenty to thirty minutes. If nitrobenzol be present, it will be 
indicated at this point by its odor. When the oxidation of the aldehyde 
is complete, remove the flask from the water-oven, transfer the contents 
to a separatory funnel, rinsing off the watch-glass, add 10 cc. of a 20% 
sulphuric acid solution, and cool the contents of the funnel to room 
temperature under the water tap. Extract the benzoic acid with three 
portions of 50, 30, and 20 cc. of ether, respectively, wash the combined 
extracts in another separatory funnel with two portions of from 25 to 

* Jour. Ind. Eng. Chem., i, 1909, p. 86. 



876 FOOD INSPECTION AND ANALYSIS. 

30 cc. of distilled water, or until all the sulphuric acid is removed. Filter 
into a tared dish, wash with ether, allow to evaporate at room tempera- 
ture, and finally dry over night in a desiccator, and weigh. The per 
cent of benzaldehyde {B) is obtained from the weight of the acid (W) 
by the following formula: 

0.869X10XTF 
1.045 

If desired the benzoic acid may be titrated, and the benzaldehyde 
calculated from the amount of standard alkali required for neutrahza- 
tion. The process is as follows: Dissolve the benzoic acid obtained as 
above described, except that it need not be dried in a desiccator, in 95% 
alcohol made neutral to phenolphthalein with tenth-normal sodium 
hydroxide, dilute with an equal volume of water, and titrate with tenth- 
normal sodium hydroxide, using phenolphthalein as indicator. The 
per cent of benzaldehyde {B) is calculated from the cc. of tenth-normal 
alkali (F) by the following formula: 

FX0.01061XTO 
1.045 

Detection of Nitrobenzol.* — Boil 15 cc. of the extract in a test-tube 
with a few drops of a strong solution of potassium hydroxide. Nitro- 
benzol produces a blood-red coloration. 

Distinction between Benzaldehyde and Nitrobenzol. — Treat 20 cc. 
of the extract with 5 to 10 cc. of a cold, saturated aqueous solution of 
sodium bisulphite in a test-tube, and shake vigorously. Transfer to 
an evaporating-dish, and heat on the water-bath till the alcohol is driven 
off. At this stage benzaldehyde remains in the hot solution as a crystal- 
line salt, and the solution gives off no almond odor. 

Nitrobenzol, on the contrary, does not combine with the bisulphite 
and is insoluble, forming globules of oil on the surface of the hot liquid, 
and in addition giving off the pungent odor so characteristic of the sub- 
stance. 

Separation of Nitrobenzol and Benzaldehyde. — If by the qualitative 
test nitrobenzol is found, shake vigorously as before 50 cc. of the extract 
with 10 cc. of the saturated sodium bisulphite solution in a corked flask, 
and transfer with 100 cc. of water to a large separatory funnel. Shake 
out the nitrobenzol from the solution with four successive portions of 

* Holde, Jour. Soc. Chem. Ind., 13, 1893, p. 906. 



FL/tyORING EXTRACTS AND THEIR SUBSTITUTES. 877 

petroleum ether of 15 to 20 cc. each, and after washing with water the 
combined petroleum ether, transfer it to a tared dish, in which it is allowed 
to evaporate spontaneously. 

It is extremely difhcult to avoid loss of some of the nitrobenzol by 
this process, but even if the weighed residue fails to show the full amount 
originally used, enough will usually be extracted to admit of testing on 
the rcfractometer, and of otherwise verifying its character. 

After removal of the nitrobenzol, make the residual solution in the 
separatory funnel strongly alkaline with sodium hydroxide, and shake 
out the benzaldehyde, if present, with petroleum ether as previously 
described. If after making the solution alkaline no odor of benzalde- 
hyde is apparent, the absence of benzaldehyde may be inferred. 

Distinction between Artificial Benzaldehyde and Pure Almond Oil. — 
Test the final residue from the ether extract by shaking with an equal 
volume of concentrated sulphuric acid in a test-tube. With natural 
oil of almonds a clear, brilliant, but dark currant-red color is produced, 
while with artificial benzaldehyde,. the acid produces a dirty brown color 
with the formation of a precipitate. 

Determination of Alcohol. — In the absence of other flavoring sub- 
stances than nitrobenzol and benzaldehyde, which are rarely present 
to an extent exceeding 1%, a sufficiently close approximation for most 
purposes can be gained by estimating the alcohol from the direct specific 
gravity of the extract. 

Detection of Hydrocyanic Acid. — To a few cubic centimeters of 
extract in a test-tube add a few drops of a mixture of solutions of ferrous 
sulphate and ferric chloride, the ferrous salt being in excess. Make 
alkaline with sodium hydroxide, and add enough dilute hydrochloric 
acid to dissolve the precipitate formed by the alkali. Presence of a blue 
coloration or precipitate, due to the formation of Prussian blue, indicates 
hydrocyanic acid. The reaction is very delicate. 

Determination of Hydrocyanic Acid.* — Hydrocyanic acid may be 
determined by titration with tenth-normal silver nitrate solution. 25 cc. 
of the extract are measured into a flask, and 5 cc. of freshly prepared 
magnesium hydroxide suspended in water are added, or enough to 
make the reaction alkaline. 

A few drops of a solution of potassium chromate are then introduced, 
and the tenth-normal silver nitrate solution added till, with shaking, the 
formation of the red silver chromate indicates the end-point, i cc. of 
silver solution equals 0.0027 gram of hydrocyanic acid. 

* Vielhaber, Arch. Pharm. (3), 13, 408. 



878 FOOD INSPECTION AND ANALYSIS. 



WINTERGREEN EXTRACT. 



Wintergreen Oil. — True oil of wintergreen is obtained by distillation 
from the leaves of the wintergreen plant {Gaultheria procumbens L.). 
Gildermeister and Hoffman * state that the specific gravity at 1 5° is 
1. 180 to 1.187, the boiling-point 218 to 221° C. It is shghtly laevo- 
rotatory (a^= — 0.0° 25' to —1°). 

Oil of betula or svi^eet birch is distilled from the bark of the black 
birch (Betula lenta L.). It has the same specific gravity and boiling- 
point as oil of wintergreen, but unlike the latter is optically inactive. 
It differs somewhat from oil of wintergreen in taste and odor, but is 
hardly distinguishable in these respects from synthetic methyl salicylate. 

Both oil of wintergreen and oil of sweet birch consist almost entirely 
of methyl salicylate, the former containing, according to Power and 
Kleber,t as much as 99.8% of this substance. 

U. S. Standards. — Oil of Wintergreen is the volatile oil distilled from 
the leaves of the Gaultheria procumbens L. 

Wintergreen Extract is the flavoring extract prepared from oil of 
wintergreen, and contains not less than 3% by volume of oil of winter- 
green. 

Spirit of Gautheria of the U. S. P. is a mixture of 50 cc. of oil of 
wintergreen and 950 cc. of alcohol. It accordingly contains 5% by volume 
of the essential oil. 

Adulteration of Wintergreen Extract. — Synthetic methyl salicylate 
is very commonly substituted for both wintergreen and sweet birch oil, 
and sweet birch oil in turn for wintergreen oil. The production of true 
wintergreen oil is small, the so-called natural wintergreen oil of com- 
merce being usually sweet birch oil. The sense of smell is the best 
means of distinguishing the two oils; polarization is of rather uncertain 
value, owing to low rotatory power of the wintergreen oil. 

Determination of Wintergreen Oil. — Hortvet and Wesi^s Method.% 
— Measure 10 cc. of the extract into a loo-cc. beaker, add 10 cc. of 10% 
potassium hydroxide solution, and heat the mixture over a boiling water- 
bath until the odor of oil of wintergreen has disappeared and the liquid 
is reduced to about one-half its original volume. By this treatment 
the methyl salicylate is converted into the potassium salt. Liberate the 

* The Volatile Oils. Translated by Kremers, Milwaukee, 1900, p. 588. 

t Pharm. Rund., 13, p. 228. 

I Jour. Ind. Eng. Chem., i, 1909, p. 90. 



FLAFORING EXTRACTS AND THEIR SUBSTITUTES. 



879 



salicylic acid by the addition of an excess of 10% hydrochloric acid, 
cool, and extract in a separatory funnel with three portions of 40, 30, 
and 20 cc. of ether respectively. Pour the combined ether extracts 
through a dry filter into a weighed dish, wash the filter with 10 cc. of 
ether, evaporate filtrate and washings slowly at 50° C, dry one hour 
in a desiccator, and weigh. The per cent of wintergreen oil by volume 
(M) is obtained from the weight of salicyhc acid {S) by the following 
formula: 

i.ioiXioX5 



M= 



i.iJ 



Howard^s Method. — Proceed as described on page 865, except that 
the heavy oil is brought into the graduated portion of the Babcock bottle 
by addition of dilute sulphuric acid (1:2), taking care that the acid is 
not over 25° C. and avoiding agitation. 



PEPPERMINT EXTRACT 

Peppermint Oil is obtained from various plants of the genus Mentha^ 
which are commonly classed as sub-species or varieties of M. piperita. 
Owing in large part to the botanical differences in the plants from which 
it is made, peppermint oil from different regions differs greatly in its 
chemical and physical constants as shown by the following table com- 
piled from figures given by Gildermeister and Hoffmann : * 



American o-905 to 0.920 

English 0.900 to 0.910 

Japanese o . 895 to o . 900 

Saxon o . 900 to o . 91 5 

German ' 0.899 to °-93° 

French 0.918 to 0.920 

Russian I 0.905 to 0.910 



Specific Gravity. 



Rotation, Orj. 



-18° to -2,Z° 
-22° to -2,f 

- 30° to — 42° 
-25° to -33° 
-27° to -33° 

- 5° to - 9° 
-17° to -22° 



Total Menthol, 
Per Cent. 



48 to 60 
56 to 66 
70 to 91 
54 to 68 

43 to 46 

50.2 



U. S. standards. — Peppermint is the leaves and flowering tops of 
Mentha piperita L. 

Oil of Peppermint is the volatile oil obtained from peppermint, and 
contains not less than 50% by weight of menthol. 

Peppermint Extract is the flavoring extract prepared from oil of pepper- 



* The Volatile Oils. Translated by Edward Kremers, Milwaukee, 1900. 



88o FOOD INSPECTION AND ANALYSIS. 

mint, or from peppermint, or both, and contains not less than 3% by 
volume of oil of peppermint. 

Analysis of Peppermint Extract. — Owing to the wide variation in the 
rotatory power of peppermint oil, only a roughly approximate idea of 
the oil content of peppermint extract can be gained by polarization. 
The variation in the percentage of menthol in the oil is also too great 
to perm.it of a method based on the amount of this constituent. Mitchell's 
precipitation method, as originally described (page 864), does not elifect 
a complete separation of the oil, but Howard's modification (page 865) 
gives satisfactory results, and is well adapted for purposes of inspection. 

SPEARMINT EXTRACT. 

U. S. Standards. — Spearmint is the leaves and flowering tops of Mentha 
spicata L. 

Oil of Spearmint is the volatile oil obtained from spearmint. 

Spearmint Extract is the flavoring extract prepared from oil of spear- 
mint, or from spearmint, or both, and contains not less than 3% by 
volume of oil of spearmint, 

SPICE EXTRACTS. 

Alcoholic solutions of the essential oils of spices are used to some 
extent instead of the sj)ices themselves. The following are the definitions 
of these extracts and the oils from which they are prepared, as adopted 
by the joint committee on standards and the U. S. Secretary of Agri- 
culture : 

U. S. Standards. — Anise Extract is the flavoring extract prepared 
from oil of anise, and contains not less than 3% by volume of oil of 
anise. 

Oil of Anise is the volatile oil obtained from the ^nise seed. 

Celery Seed Extract is the flavoring extract prepared from celery seed 
or the oil of celery seed, or both, and contains not less than 0.3% by 
volume of oil of celery seed. 

Oil of Celery Seed is the volatile oil obtained from celery seed. 

Cassia Extract is the flavoring extract prepared from oil of cassia, 
and contains not less than 2% by volume of oil of cassia. 

Oil of Cassia is the lead-free volatile oil obtained from the leaves 
or bark of Cinnamomum cassia Bl., and contains not less than 75% by 
weight of cinnamic aldehyde. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 8Sl 

Cinnamon Extract is the flavoring extract prepared from oil of cinna- 
mon, and contains not less than 2% by volume of oil of cinnamon. 

Oil of Cinnamon is the lead-free volatile oil obtained from the bark 
of the Ceylon cinnamon {Cinnamomum zeylanicum Breync), and contains 
not less than 65% by weight of cinnamic aldehyde and not more than 
10% by weight of eugenol. 

Clove Extract is the flavoring extract prepared from oil of cloves, and 
contains not less than 2% by volume of oil of cloves. 

Oil of Cloves is the lead-free, volatile oil obtained from cloves. 

Ginger Extract is the flavoring extract prepared from ginger, and 
contains in each 100 cc. the alcohol-soluble matters from not less than 
20 grams of ginger. 

Nutmeg Extract is the flavoring extract prepared from oil of nutmeg, 
and contains not less than 2% by volume of oil of nutmeg. 

Oil of Nutmeg is the volatile oil obtained from nutmegs. 

Savory Extract is the flavoring extract prepared from oil of savory, 
or from savory, or both, and contains not less than 0,35% by volume of 
oil of savory. 

Oil of Savory is the volatile oil obtained from savory. 

Star Anise Extract is the flavoring extract prepared from oil of star 
anise, and contains not less than 3% by volume of oil of star anise. 

Oil of Star Anise is the volatile oil distilled from the fruit of the star 
anise {Illicium verum Hook). 

Sweet Basil Extract is the flavoring extract prepared from oil of 
sweet basil, or from sweet basil, or both, and contains not less than 0.1% 
by volume of oil of sweet basil. 

Sweet Basil, Basil, is the leaves and tops of Ocymum basilicum L. 

Oil of Sweet Basil is the volatile oil obtained from basil. 

Sweet Majoram Extract, Majoram Extract, is the flavoring extract 
prepared from the oil of majoram, or from majoram, or both, and 
contains not less than 1% by volume of oil of majoram. 

Oil of Majoram is the volatile oil obtained from majoram. 

Thyme Extract is the flavoring extract prepared from oil of thyme, 
or from thyme, or both, and contains not less than 0.2% by volume of 
oil of thyme. 

Oil of Thyme is the volatile oil obtained from thyme. 

Determination of Essential Oil in Cinnamon, Cassia, and Clove 
ExtvaiCts.— Howard's Method.— Proceed as with wintergreen extract, 
page 879. 



882 FOOD INSPECTION AND ANALYSIS. 

Hortvet and Wesfs Method.'^ — Place lo cc. of the extract and 50 cc. 
of water in a separatory funnel, and extract with three portions of ether 
measuring respectively 50, 30, and 20 cc. Wash the combined extracts 
successively with 25 and 30 cc. of distilled water, and filter through a 
dry funnel into a wide-mouth flask, washing out the funnel and filter 
with a httle ether. In the case of cinnamon extract, transfer the ether 
extract before filtering to a 150-cc. flask, shake for a few minutes with 
some granulated calcium chloride, then filter in the manner described. 
Evaporate off the ether as rapidly as possible on a boiling water-bath 
until only a few drops remain. At this point remove the flask from the 
bath, and rotate rapidly for a few minutes, spreading the residue over 
the sides of the flask. The rapid evaporation of the remaining ether cools 
the flask to near room temperature. When the odor of ether has dis- 
appeared, stopper the flask and weigh. 

In the case of cassia and clove oils, where the ether extract is not 
first dried with calcium chloride, a slight cloudiness gathers on the flask 
as the last traces of ether disappear, due to the presence of a little 
moisture. In such case allow the flask to stand on the balance-pan 
until the film disappears, requiring not longer than two to three minutes, 
then stopper, and weigh. 

The per cent of oil by volume (F) is calculated from the weight of 
oil (IF) by the following formula: 

100 X IF 
F=- 



loX 1.050 



The oil thus extracted may be used for determination of the refractive 
Index. After dissolving in a little alcohol it may be tested with ferric 
chloride solution. By this test cinnamon oil gives a green, cassia oil a 
brown, and clove oil a deep blue, coloration. 

Determination of Essential Oil in Nutmeg Extract. — Follow Mitchell's 
precipitation method, page 865. 

ROSE EXTRACT. 

U. S. standards. — Rose Extract is the flavoring extract prepared from 
otto of roses, with or without red rose petals, and contains not less than 
0.4% by volume of otto of roses. 

Otto of Roses is the volatile oil obtained from the petals of Rosa 
damascena Mill., R. cen tifolia L., or R. moschata L. 

* Jour. Ind. Eng. Chem., i, 1909, p. 88. 



FLAl^ORING EXTRACTS AND THEIR SUBSTITUTES. 883 

Determination of Rose Oil.—Hortvet and West's Method* — Measure 
25 cc. of the extract into a separatory funnel, add 50 cc. of water, mix 
thoroughly, acidify with i cc. of hydrochloric acid (1:1), and extract 
with three portions of 20 cc. each of ether. Transfer the combined 
ether extracts to a 150-cc. flask, shake for a few minutes with some 
granulated calcium chloride, allow to settle until clear, then decant 
through a dry filter into a flat bottom glass dish previously weighed 
together with a cover-glass. Wash the calcium chloride and filter twice 
with 10 cc. of ether, and add the washings to the glass dish. Cover 
the dish, place in a vacuum desiccator over sulphuric acid, allow to 
remain until all traces of ether and alcohol are removed, and weigh. 
Repeat the drying in the desiccator, for one hour periods, until the weight 
is practically constant. The final weight, divided by 0.86 and muhiplied 
by 5, gives the per cent of oil of rose by volume. 

IMITATION FRUIT FLAVORS. 

Nearly all the fruits possess distinctive flavors, which are desirable 
in food preparations, and which may be made to impart their flavor to 
such substances as confections, ice cream, dessert mixtures, jellies, etc., 
by simply mixing with these foods the fresh or preserved fruit or fruit 
juice in sufficient quantity. In many cases, however, it is not found 
possible or practicable to prepare from the fruits themselves an extract 
sufficiently concentrated to give the distinctive fruit flavor, when used 
in moderate quantity, and hence the use of artificial fruit essences made 
up of compound ethers, mixed in varying combinations and proportions 
to imitate more or less closely various fruit flavors. 

These ethers are usually much more pungent and penetrating than 
the fruits w^hich they imitate, and, while lacking the delicacy and refine- 
ment of the original fruits, serve to impart a certain semblance of the 
genuine flavor in a convenient and highly concentrated form. 

Some of the single compound ethers possess a remarkable resemblance 
to particular fruits, while to imitate other fruits a mixture of various 
ethers and flavoring materials, such as lemon and other volatile oils, 
vanilla, organic acids, chloroform, etc., is necessary. These artificial 
essences should in all cases be sold as such, and not as "pure fruit flavors." 

* Jour. Ind. Eng. Chem., i, 1909, p. 89. 



884 FOOD INSPECTION AND ANALYSIS. 

Imitation Pineapple Essence is made up by dissolving in alcohol butyric 
ether, C4H7(C2H5)02, which possesses a distinct pineapple flavor, and 
is prepared by mixing loo parts of butyric acid (C^HgOj), loo parts of 
alcohol, and 50 parts of sulphuric acid, and shaking. Butyric ether is 
sparingly soluble in water, and boils at 121° C. 

Imitation Quince Essence depends as a basis on ethyl pelargonate, 
sometimes called pelargonic or oenanthic ether, CjHjjCgHiyOa, dissolved 
in alcohol. Pelargonic ether is formed by digestion with the aid of heat 
of pelargonic acid and alcohol. Pelargonic acid, CyH^gOj, is tirst obtained 
by the action of nitric acid on oil of rue. Pelargonic ether is a colorless 
liquid, having a specific gravity of 0.8635 ^-t 17.5° C. Its boiling-point 
is 227° to 228° C. It is insoluble in water. 

Imitation Jargonelle Pear Essence consists of an alcoholic solution 
of amyl or pentyl acetate, C5Hii,C2H302. This is prepared by distilling 
a mixture of one part of amyl alcohol, two parts of potassium acetate, 
and one part of concentrated sulphuric acid. It is a colorless liquid, 
insoluble in water, and having a boiling-point of 137° C. 

Imitation Banana Essence is made up of a mixture of amyl acetate 
and butyric ether. 

Imitation Apple Essence is composed of an alcoholic solution of amyl 
valerianate, sometimes called apple oil, CsHnjCsHgOj, prepared by mixing 
four parts of amyl alcohol with four of sulphuric acid, and adding 
the mixture when cold to five parts of valerianic acid. The specific 
gravity of amyl valerianate is 0.879 ^-t 0° C. and its boiling-point is 188° C. 

The table on p. 885, prepared by Kletzinsky, shows the composition 
of a large variety of these artificial essences. The numerals in the various 
columns indicate the parts by volume to be added to one hundred parts of 
deodorized alcohol. 

Determination of Esters. — Add to 25 grams of the extract 2 cc. of 
sodium hydroxide solution (100 grams in 100 cc. of water), 100 cc. of 
water and heat under a reflux condenser one half-hour. Acidify with 
5 cc. of dilute sulphuric acid (1:4), add a few pieces of pumice stone, 
distil in a current of steam and titrate the distiUate with tenth-normal 
alkali, using phenophthalein as indicator. The number of cc. required 
represents the total volatile acids free and combined. Determine 
free volatile acids, if present by direct distillation and titration of the 
distillate. The difference between the two titrations is calculated as 
ethyl acetate. 



CANNED AND BOTTLED VEGETABLES, ETC 



88s 



COMPOSITION OF IMITATION ESSENCES. 





i 

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Raspberry 






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Black cherry. ... 


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Raspberry. .......... 










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886 FOOD INSPECTION ^ND /iNALYSIS, 



REFERENCES ON FLAVORING EXTRACTS. 

Chace, E. M. a Method for the Determination of Citral in Lemon Oils and Extracts. 

Jour. Am. Chem. See, 28, 1906, p. 1472. 
The Detection of Small Quantities of Turpentine in Lemon Oil. Ibid., 30, 1908, 

P- 1475- 
GiLDEMEiSTER, E., and Hoffmann, F. The Volatile Oils. Trans, by Edward 

Kremer. Milwaukee, 1900. 
Hess, W. H. The Distinction of True Extract of Vanilla from Liquid Preparations 

of Vanillin. Jour. Am. Chem. Soc, 21, 1899, p. 719. 
Hess, W. H., and Prescott, A. B. Coumarin and Vanillin, their Separation, Estima- 
tion and Identification in Commercial Flavoring Extracts. Jour. Am. Chem. 

Soc, 21, 1899, p. 256. 
Heusler, F. The Chemistry of the Terpenes. Trans, by F. J. Pond. Philadelphia, 

1902. 
HiLTNER, R. S. The Determination of Citral in Lemon Extract. A. O. A. C. Proc, 

1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 34. Jour. Ind. Eng. 

Chem., I, 1909. 
HoRTVET, J., and West, R. M. The Determination of Essential Oils and Alcohol 

in Flavoring Extracts. Jour. Ind. Eng. Chem., i, 1909, p. 84. 
Howard, C. D. The Precipitation Method for the Estimation of Oils in Flavoring 

Extracts and Pharmaceutical Preparations. Jour. Am. Chem. Soc, 30, 1908, 

p. 608. 
Mitchell, A. S. Lemon Flavoring Extract and its Substitutes. Jour. Am. Chem. 

Soc, 21, 1899, p. 1 132. 

Flavoring Extract^;. U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 69. 

WiNTON, A. L., and Silverman, M. The Analysis of Vanilla Extract. Jour. Am. 

Chem. Soc, 24, 1902, p. 11 29. 
WiNTON, A. L., and Bailey, E. M. The Determination of Vanillin, Coumarin, and 

Acetanilide in Vanilla Extract. Jour. Am. Chem. Soc, 27, 1905, p. 719. 



CHAPTER XXI. 

CANNED AND BOTTLED VEGETABLES, RELISHES, AND FRUIT 

PRODUCTS. 

CANNED VEGETABLES AND FRUITS. 

Strictly speaking all varieties of canned foods found in the market, 
whether meats, fruits, or vegetables, in order to be entirely beyond criti- 
cism, should not differ from the corresponding freshly cooked varieties 
which they are intended to replace, excepting that they are free from 
bacteria. Such a degree of perfection is, however, difficult, even if pos- 
sible, to attain, and nearly all commercial canned products, even if made 
from the best materials, are liable to contain either antiseptic substances 
or coloring-matter intentionally added by the manufacturer, or metallic 
impurities accidentally derived from the vessels in which they are pre- 
pared, or from the containers in which they are sealed. In spite of these 
objections, canned foods form a convenient, and in some cases indispensa- 
ble means of furnishing both necessities and luxuries for the table. The 
canning of foods is especially useful for preserving them during long 
periods of time, for enabling certain fruits and vegetables to be enjoyed 
out of season, and for furnishing supplies in a convenient manner to inac- 
cessible places where fresh foods are not readily obtainable, as in the 
case of armies in the. field, of vessels at sea, of campers in the woods, etc. 
Canned goods in great variety are used in nearly every household. 

When it is considered that in the United States alone something like 
one hundred million cans of corn are packed in a single year, about the 
same quantity of peas, and one hundred and fifty million cans of tomatoes, 
to say nothing of an ever-increasing variety of other foods, some idea may 
be gained of the enormous proportions to which the canning industry 
has grown. It is comforting to know that, in view of their wide-spread 
consumption, the greater portion of such foods found on the market are 

887 



888 FOOD INSPECTION AND ANALYSIS. 

comparatively harmless, as is evidenced by the fact that few cases of injury 
to health have been directly traceable to their use. 

Method of Canning Food. — Various modifications as to details exist 
with different products and in different localities, but in general the prin- 
ciple of canning in tin is the same in all cases. The fresh product is 
cleaned carefully, and packed in cans with the requisite amount of water. 
The cans are then sealed, and subjected to the effect of steam or boiling 
water till the contents are thoroughly cooked. Each can is then tapped 
or punctured at one end to expel the air, and again heated, after which 
the hole is closed by a lump of solder, thus forming a vacuum in the can, 
which is afterwards heated for a sufficient time to destroy the bacteria, 
usually for several hours. 

The above mode of procedure is the time-honored one, and is still in 
vogue in most localities, but a more modern method, much in use at present, 
consists in first cooking the food at a temperature of 82° to 88° C. before 
transferring to the cans, and afterwards subjecting the cans when sealed 
to a high heat of about 125° C. in dry air in so-called retorts, this heating 
or "processing," as it is termed, being carried on for a sufficient length 
of time to completely sterilize the contents of the can. Obviously a much 
shorter time is required for this than when the temperature of boiling 
water is employed, and the sterilization is much more effective. 

Cooked vegetables and fruit products put up in glass jars or bottles 
are tightly sealed when hot, either with screw-caps or with some form of 
cover held by a clamp, or with metal or hard-rubber caps fitting over a 
flanged mouth. Frequently a soft-rubber ring is inserted between the 
cover and the mouth of the jar or bottle. The material of the cover is 
generally either glass, porcelain, or metal. Cork stoppers are, however, 
sometimes pressed into the mouths of the bottles, and made extra tight 
therein with sealing-wax. These stoppers are occasionally soaked in 
paraffin. Thus the contents of the jar may be exposed to porcelain, 
glass, metal, rubber, or cork, according to the material of the cover and 
the method of sealing. 

The preservation of food by canning was long thought to be due to 
the perfect exclusion of air, but is now known to depend on the perfect 
sterilization, or destruction of bacteria, and it has been proved that as 
far as keeping qualities are concerned, it makes no difference whether 
or not air is present in the can, if the contents arc sterile, though for pur- 
poses of inspection the vacuum, in the case of tin cans, is of great use, in 
that as a natural consequence of the vacuum, when the goods are sound, 



CANNED AND BOTTLED VEGETABLES, ETC. 



the ends of the can are usually concave. The highest aim of the canner 
should be to retain in his product as far as possible the appearance, pala- 
tability, and nutritive value of the freshly cooked food. 

PROXIMATE COMPOSITION OF CANNED VEGETABLES AND FRUITS * 



CANNED VEGETABLES 

Artichokes 

Asparagus 

Beans, baked 

' ' string 

" Lima 

Brussels sprouts 

Com, green 

Peas, green 

Pumpkin 

Squash 

Succotash 

Tomatoes 

CANNED PKUITS. 

Apples, crab 

Apple sauce 

Apricots 

Blackberries 

Blueberries 

Cherries 

Peaches 

Pears 

Pineapples 

Strawberries 



O cii 

. a 



3 
14 
21 
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600 

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150 
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455 
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1,120 

730 
340 
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275 
415 
220 

355 
715 
460 



*U. S. Dept. of Agric, Exp. Sta. Bui. 28, p. 70. 

Methods of Proximate Analysis. — ^As a rule, the contents of canned 
goods are intended to be entirely edible throughout, and contain little 
or no refuse or portions to be rejected. An exception to this is the occa- 
sional canning of certain fruits with stones or pits, which are, of course, 
to be removed. The can or package is first weighed before opening, and 
later the cleaned receptacle is weighed after its contents have been removed. 
The weight of the contents is thus ascertained by difiference. 

For the analytical determinations, the contents of the can or bottle 
are intimately mixed to form a homogeneous pulp, so that parts taken 
for analysis are fairly representative of the whole. If considerable liquid 
is present, with some solid masses held in suspension therein, the liquid 
is best drained oflf, and the solid portions pulped separately in any con- 
venient manner, as by the use of a mortar, or by means of a household 



890 FOOD INSPECTION /IND ANALYSIS. 

food-chopper. The whole is then thoroughly mingled together. If 
desired, the weight of the liquid and solid portions may be separately 
ascertained before mixing. 

The analyst should use judgment and discrimination as to how 
various portions of the mass are to be best measured out for the deter- 
minations. Much depends on the consistency of the pulpy mass. It 
is often convenient to make a 20% solution or mixture of the material 
with water, using say 50 grams of the pulped sample in 250 cc. of water, 
such of the sample as is insoluble being disintegrated by shaking. 

Methods for determining water, ether extract, crude liber, protein, 
and ash do not differ materially from those employed in the case of cor- 
responding fresh fruits and vegetables. 

These determinations, in the case of canned products, while useful 
in showing their food value, give little information as to their adulteration 
by the substitution of foreign vegetable or fruit pulp. 

Accidental Impurities. — Under this head are included (i) products 
of decomposition, due to the incomplete sterilization of the contents of 
the can, and (2) metallic salts due to the solvent action of the juices of the 
contents on the inner surface of the can, or of the vessel in which the 
product has been previously cooked. 

Decomposition, and the Detection of Spoiled Cans. — In the case of 
canned vegetable products, decomposition rarely results in the formation 
of ptomaines even after the can has long been open, though these toxins 
are sometimes formed, in canned meat and fish. Decomposition is readily 
apparent after opening a can, from a cursory examination of its contents. 
The appearance, taste, and odor will not fail to indicate the unfitness 
of the contents for food, if decomposition is at all advanced. It is, how- 
ever, often of great advantage to detect spoiled cans without opening. 
As a rule, when a can is spoiled, it is usually in the condi ion termed 
"blown," i.e., with its ends convex, instead of normal or concave. 

According to Prescott and Underwood,* although nearly all forms of 
bacterial decomposition are accompanied by bulging of the ends of the 
cans, there are some exceptions. In the souring of canned sweet corn,f 
for instance, it is exceptional that swelling occurs. Ordinarily, in the 
factory inspection of canned goods before shipping, not only are the 
bulged cans or "swells," as they are termed, sifted out, but the condition 

* Tech. Quart., ii, 1898, pp. 6-30; also 10, 1897, p. 183. 

t These experimenters found at least twelve varieties of bacteria to which the souring of 
com is apparently due. 



CANNED AND BOTTLED {VEGETABLES, ETC. 



891 



of the cans is tested by sounding or striking the cans. If the contents 
are sweet, a peculiar note is produced when the can is struck, readily 
distinguishable from the dull tone of the unsound can by any one familiar 
with the work. 

As stated above, concavity in the ends of the can indicates that the 
contents are in good condition. 

Prescott and Underwood further state that sound cans may be dis- 
tinguished from unsound in a lot of suspicious goods, when the swelling 
of the ends is not apparent, by the following method: 

Boil the cans for an hour, causing the ends of all to swell, then cool, 
and set aside for eight hours, during which the sound cans will snap back, 
while the unsound will continue convex, by reason of the fact that the 
swelling in this case is due to the generation of gas by the bacteria 
present. 

Examination of Gases from Spoiled Cans. — When the tops of blown 
cans are punctured in the process of opening, an outflow of gas is usually 
to be noted. Doremus * has studied the character of these gases and 




Fig. 119. — Apparatus for Collecting Gases from Spoiled Cans. (After Doremus.) 

found that when the contents have become putrid, carbon dioxide and 
hydrogen are the chief gases to be found. Often 60 tt) 80 cc. of gas 
may be collected from a can. For the collection of the gases, Doremus 

* Jour. Am. Chem. Soc., 19, 1897, p. 733. 



392 FOOD INSPECTION AND ANALYSIS. 

uses the device sho\vn in Fig. 119. An adjustable clamp has attached 
to its upper arm a beveled, hollow, steel needle. A perforated rubber 
stopper covers the needle and serves as a cushion. A fine tube 
connects the needle with the receiver of a eudiometer, both tube and 
receiver being filled with water or mercury. Either the stop-cock form 
of eudiometer, as here shown, or the kind with attached leveling-tube 
may be used. The can is adjusted between the arms of the clamp, 
and by turning the screw the needle is brought into contact with the 
top of the can and caused to puncture it, the rubber stopper serving 
to make a gas-tight joint. The gas passes through the tube into the 
eudiometer, and its constituents are determined in the usual manner, 
either by introducing the reagents directly into the eudiometer-tube in 
the proper order, or by transferring the gases to pipettes.* Hydrogen 
sulphide is tested for by subjecting a filter-paper moistened with lead 
acetate solution to the gas. If it turns black, the presence of hydrogen 
sulphide is indicated. 

METALLIC IMPURITIES. 

Salts of Lead and Tin are commonly met with in varying amounts 
in nearly all classes of products put up in tin. The quantity dissolved 
depends largely on the character of the tin plate used in the manufacture 
of the can, as well as on how the solder is applied. Much depends 
also on the nature of the food product and its acidity. Formerly 
much danger was apprehended from the use of the so-called terne plate 
as a material for cans. This consists of an alloy of lead and tin, 
coated on iron plate and intended for use as roofing. Sometimes two 
parts of lead to one part of tin are found in terne plate. Only the better 
grades of bright tin plate should be used in canning. There is reason 
to believe that no terne plate is at present used in cans. In 1892 the 
plating alloy of 47 samples of tin cans in which peas had been put 
up were examined in the Bureau of Chemistry of the U. S. Department 
of Agriculture, f and the amount of lead found varied from o to 13 per 
cent. Only 4 samples were found to exceed 5 per cent, and 24 contained 
less than i per cent. 

The construction of the can should be such that practically no soldered 
surface is exposed to the contents, the joints being lapped and soldered 
on the outside. In spite of this, however, it is not unusual to find cans 

* See Thorpe's Dictionary of App'd Chem., Vol. i, pp. 159-161. 
t Bui. 13, p. 1036. 



C/fNNED AND BOTTLED VEGETyiBLES, ETC. 



893 



in which the contents have access to the solder, and it is common 
to find lumps of solder in the can from the final sealing of the tapped 
hole in the top. The amount of lead in 24 samples of solder 
taken from the interior of some of the cans mentioned in the pre- 
ceding paragraph, was found to vary between the limits of 51 and 65 
per cent.* 

Action of Fruits and Vegetables on Tin Plate.— The amount of tin 
dissolved by various canned fruits and vegetables is roughly indicated by 
the corrosion of the inner surface of the can. A large variety of these 
canned products have been examined in the laboratory- of the Massachu- 




FiG. 120. — Interior of Blueberry Cans, Cut Open to Show the Corrosion by Acid of the 

Fruit Juice. 

setts State Board of Health, u-ith a view to determining the quantity of 
tin contained in solution. The results have shown that though notable 
traces of tin were found in acid fruits and rhubarb, and large traces in 
some green vegetables, canned blueberries were found to contain, as a 
rule, much more tin in solution than any other canned goods examined. 
It is assumed that the tin was, at least in considerable part, still held in 
solution by the fruit acids, inasmuch as the metal was found in the filtered 
juice. In ever)' instance the inner tin lining was found to be exten- 
sively corroded, and in some cases it had been almost entirely dis- 
solved off, leaving the underlying iron bare. Fig. 120 shows the appear- 

* Bui. 13, p. 1038. 



894 



FOOD INSPECTION AND ANALYSIS. 



ance of one of these cans, split open to show its inner surfaces. The 
corrosion is apparent. Eleven samples of canned blueberries, represent- 
ino- seven brands, were examined in 1894 by Worcester, showing an amount 
of tin in solution (calculated as Sn02) varying from 0.066 to 0.27 gram 
per can of 615 cc. capacity. 

In 1899 samples of various canned products were examined for lead 
and tin in the author's laboratory, the results of which are thus summar- 
ized : * 



Strawberries. . 

Highest. . . . 

Lowest 

Raspberries. .. 

Highest. . . . 

Lowest 

Blueberries. . . 

Highest. . . . 

Lowest 

Tomatoes . . . . 

Highest. — 

Lowest 

String beans. . 

Highest. — 

Lowest 

Peas 

Highest. . . . 

Lowest 

Corn 

Highest. . . . 

Lowest 

Lima beans. .. 
Succotash. . . . 
Squash 

Highest. . . . 

Lowest 

Pumpkin 

Rhubarb 

Asparagus . 

Mutton broth. 
Tomato soup . 

Salmon 

Lobster 



Tin, Grams. 



-0393 
.0124 

.0848 
.0725 

.2226 
.0056 

-0515 
.0146 

-0499 
.0065 

.0046 
.0024 

-oior 
.0045 
.0064 
.0039 

■1793 
-1577 
.1844 
■3506 
.1249 
.0114 
.0023 
.0319 
.0411 



Lead, Grams. 



.0004 
.0000 



.0002 
.0001 



.0021 
.0004 



.0004 
.0001 



.0003 
.0008 



.GOOD 
.0001 

.0011 
.0001 
.0004 
.0001 

.0087 

- o°°3 
.0019 
.0002 
.0001 
.0001 
.0002 
.0001 
.0001 



Capacity of 
Can, cc. 



615 
61S 
615 
950 
650 

615 
615 

650 
650 
950 



9SO 

615 
930 
950 

370 
470 

430 



A wide range of variation exists in the amount of tin dissolved by 
various fruits. In the case of pumpkin and squash, for example, the 
tin dissolved is surprisingly large in quantity, considering the supposed 
inert nature of these vegetables. 

Samples of canned sardines put up in mustard, vinegar, and oil have 



* An. Rep. Mass. State Board of Health, 1899, p. 623. 



CANNED AND BOTTLED VEGETABLES, ETC. 



89s 



also been examined by the Massachusetts Board, and found to be high 
in tin. The highest figures showed 0.376 gram (expressed as metallic 
tin) in a half-pound can. In these cases the corrosion of the interior 
of the cans was verj' marked. 

Effect of Time on Amount of Tin Dissolved. — A series of experi- 
ments was conducted by the author in 1899 * on the action of various 
fruit acids on tin, with a view to ascertaining, among other facts, whether 
or not the element of time exerts an appreciable difference in the resuks. 

Samples of various canned fruits and vegetables were titrated for 
their acidity. It was found that certain samples of canned blueberries, 
for instance, had an acidity of about one-twentieth normal. In the case 
of strawberries, the acidity was about one-sixth normal. Canned rasp- 
berries were found to be about one-tenth normal in acidity, while the 
acidity of canned tomatoes varied from one-tenth to one-fourteenth normal. 
Solutions of one-fifth, one-tenth, and one-fifteenth-normal malic acid, 
one-tenth and one-fifteenth-normal tartaric acid, one-tenth and one- 
fifteenth-normal citric acid, and one-tenth-normal acetic acid were 
prepared and sealed in pint glass jars, having about the same capacity 
as the ordinary-sized tin fruit cans, each jar containing an amount of 
tin plate equivalent to the interior exposed surface of a can. Solutions 
thus sealed were kept for three months, six months, and a year, and 
examined at the end of these respective periods for tin. The results 
showing the amount of tin found at the end of three months in each 
case are given in the following list: 



ACTION OF FRUIT ACIDS ON TIN IN THREE MONTHS. 



Acid. 


Grams of Tin 

in One Pint of 

Solution. 


Acid. 


Grams of Tin 
in One Pint of 

Solution. 




0.0578 
0.0201 
0.0197 
0.0382 


N/15 tartaric 


0.0246 


N/io " 


N/io citric 


0.0374 
0.0236 
0.0019 


N/i:; " 


N/15 " 


N /lo tartaric 


N/io acetic 





It was found, in general, that the amount of tin dissolved in three 
months, as indicated above, was the maximum amount dissolved, or, 
in other words, with a very few exceptions no additional tin was dissolved 
by added exposure to the acid for six months, or even a year. The 

* .A.n. Rep. Mass. State BoarH '' i Health, 1899, p. 624. 



89.6 



FOOD INSPECTION /iND yIN/i LYSIS. 



amount of tin dissolved was found to vary proportionally with the strength 
of acid, as would naturally be expected. 

Experiments with tenth- normal acetic acid (which was found to be 
the approximate acidity of the canned sardines mentioned on page 894), 
sealed in jars with tin plate, as in the case of the fruit acids, and kept 
for three and six months respectively, showed that in three months 0.0019 
gram, and in six months 0.0083 gram of metallic tin had been dissolved, 
indicating much less vigorous action than that of the same strength of 
fruit acids, and dissolving less tin than the samples of sardines examined. 

Salts of Lead. — While it is a fact that the material of the tin plating 
usually found in cans is comparatively low in lead, the same is not always 
true of the metal caps used to cover some of the bottled goods. The 
French "haricots verts "are usually sold in wide-mouthed bottles, closed 
by a disk of very soft metal. In one instance this metal cap, which came 
in contact with the liquid contents of the bottle, was found to contain 
93^% of lead. Of the various kinds of bottles in which are sold cheap 
carbonated drinks known as "pop," one style has a stopper consisting of 
a metallic button surrounded by a rubber ring. These metallic buttons 
consist of tin and lead in varying proportions. Inasmuch as the inclosed 
liquor was usually found to be quite acid in reaction, the danger of pro- 
longed contact with the metallic portion of the stopper is evident. 

The following table gives the percentage of lead found in the stoppers 
of this character, together with the amount of lead contained in the liquor:* 



Character of Sample. 



Blood orange 

Birch beer 

Ginger 

Strawberry A 

Strawberry B 

Sarsaparilla A 

Sarsaparilla B 

Lemon 

Miscellaneous (20 samples) 

Maximum 

Minimum 



Per Cent of 
Lead in Stopper. 



Amount of Lead 
in Contents of 
Bottle in Milli- 
grams. t 



0-31 
Large trace 
0.40 
0.20 
0.30 
0.19 
0.17 
0.27 

1.05 
o.oi 



t Capacity of bottle about J pint. 



Besides the above tabulated samples, twenty were found with stoppers 
containing less than 3% of lead. While the amount of lead found in the 



* An. Rep. Mass. State Board of Health, 1897, p. 571. 



CANNED AND BOTTLED VEGETABLES, ETC. 897 

contents of the bottles was in no case very large, it was enough to con- 
demn the use of lead in the manufacture of such stoppers. That 
the amounts of lead found in the contents of the bottles vary quite irre- 
spective of the percentage of lead in their stoppers, may be ascribed to 
various causes, such as the difference in the acidity of the liquors, and 
the length of time that the liquor has been in contact with the stopper. 
Furthermore, the more soluble metal of an alloy is attacked by an acid 
with an energy which is not proportional to the percentage of that metal 
in the alloy. 

Salts of Zinc. — The presence of zinc salts in canned foods is largely 
accidental, and is generally due either to the contact of the acid fruits 
and vegetables with galvanized iron in the canneries, to the occasional 
use of brass vessels, or to the zinc chloride used as a soldering fluid. 
Hilgard and Colby * have examined empty tin cans fresh from the manu- 
facturer, and found zinc chloride in notable quantity in the seams, and 
especially in the empty space of the lap at the bottom of the can, where 
it could easily be acted on by the contents. The average amount of 
soluble zinc chloride found in the "lap" alone amounted to three-fourths 
of a grain per can. It was furthermore ascertained that it was not the 
practice of canners to wash the cans before packing, so that zinc present 
in canned goods may thus readily be accounted for. 

Zinc chloride is commonly used in machine soldering, but should be 
displaced by rosin. 

Hilgard and Colby found in some spoiled cans of asparagus, where 
the acidity was unusually high, an average of 6.3 grains of zinc chloride 
per large can. 

Zinc salts are said to have been used for greening peas, but their use 
for this purpose is not common. Zinc chloride is the salt used, and a 
natural yellowish-green tint is imparted when properly appHed. The 
process has been kept secret. 

Salts of Copper. — While copper in canned goods is sometimes acci- 
dental, its presence being due to the use of copper or brass vessels in the 
canneries, its chief interest to the food analyst lies in the use of copper 
sulphate for greening peas and other vegetables. The artificial greening 
of vegetables is much more commonly practiced in France than in the 
United States. 

French canners of peas, beans, Brussels sprouts, etc., are frequently 
so lavish in the use of sulphate of copper that the goods as found on our 
* Rep. Cal. Agric. Exp. Sta., 1897-8, p. 159. 



898 FOOD INSPECTION AND ANALYSIS. 

markets can in some cases hardly be said to resemble the freshly cooked 
products in color. Oftentimes, indeed, they possess such a deep green 
as to be positively distasteful to the average American palate, though 
evidently this unnatural hue is craved in Europe. The use of copper 
in such foods is often rendered apparent by the most cursory examina- 
tion. 

In this country, when copper is used, smaller quantities are usually 
employed, with an attempt to imitate more closely the color of the natural 
product. 

Complaint in court for this form of adulteration under the general 
food law as it exists in most states would naturally be brought under one 
of two clauses : 

ist. As being colored, whereby the product appears of greater value 
than it really is, or 

2d. As containing an ingredient injurious to health. 

An ingenious claim is sometimes advanced by the defendant in oppo- 
sition to clause i, to the effect that copper sulphate is added, not to give 
an artificial green color, but to preserve the original green of the chloro- 
phyl or natural color of the fresh peas,* so that it will not be destroyed 
by subsequent boiling. 

This point was argued in a strongly contested court case brought in 
Massachusetts for copper in French peas.| 

As Worcester % has shown, the fallacy of this argument can be easily 
demonstrated. If it were true that the copper acts as a preservative of 
the chlorophyl, a pure extract of chlorophyl should, l^y the addition of 
copper sulphate, be prevented from destruction on boiling, and again, 
on once destroying the color of the chlorophyl by boiling, it would be 
impossible to restore it by further boiling it with copper sulphate. 

As a matter of fact, if an extract of chlorophyl is boiled with a dilute 
solution of copper sulphate, its color is at once destroyed, and a brown 
precipitate is thrown down. On the other hand, if yellow or white peas 
or beans devoid of chlorophyl are boiled with copper sulphate, they are 
colored green, the depth of color depending on the strength of the copper 
solution. When peas or other vegetables are thus colored, very little 
copper is found, as a rule, in the liquid contents of the can, but the copper 
is chiefly confined to the solid portions. Green compounds are produced 



* The term used by the French to describe this process is reverdissage or " regreening. ' 
t An. Rep. Mass. State Board of Health, 1892, p. 605. 
t Loc cit., supra, p. 641- 



CANNED AND BOTTLED {VEGETABLES, ETC. 899 

by boiling albumins with copper salts, due to the fcrmation of albuminate, 
or in the case of peas, leguminate of copper. Harrington * states that it is 
possible to color eggs an intense green by boiling with copper sulphate. 

Examination of a large number of brands of canned vegetables greened 
by copper, as bought in Massachusetts, showed that the amount used 
varied from a trace to 2.75 grams per can, calculated as copper sulphate. 
In justice to the consumer, who may be cautious about taking into his 
system copper salts, as well as to those who are indifferent to their use, 
it is no more than fair that all cans should have a label, plainly stating 
the quantity present. In the Massachusetts market, labels like the fol- 
lowing are not uncommon: "This package of French Vegetables con- 
tains an equivalent of Metallic Copper not exceeding three-quarters of 
a grain." 

Copper as a coloring matter has been most commonly found in peas, 
beans, and Brussels sprouts. Copper salts in minute quantity have been 
found in Massachusetts in canned tomatoes, clams, and squash, as well 
as in pickles. 

Salts of Nickel. — Sulphate of nickel has been employed instead of 
sulphate of copper for greening vegetables. According to Harrington f 
0.25 gram of nickelous sulphate per kilogram of peas is used. The peas 
or other vegetables are boiled in a solution of the salt, made slightly alka- 
line with ammonia. 

Toxic Effects of Metallic Salts. — Divergence of opinion is so great 
as to the toxic effects of salts of the heavy metals on the human system, 
when present in the small amounts commonly found in food products, 
that it is extremely difficult to maintain a complaint in court based 
entirely on the harmful effects of these salts. Since the question is one 
for the toxicologist or physiological chemist rather than the analyst to 
settle, it will not be discussed here at length ; suffice it to say that a large 
number of experiments on human beings will undoubtedly have to be 
tried, before the necessary data will be at hand on which to base a really 
intelligent opinion. The same general difficulties are met with here as 
one encounters in the matter of determining the definite effects of anti- 
septics in food, of alum in baking-powder, etc. 

Determination of Lead in Tin Alloy. — Method of Paris Municipal 
Lahoratory.X — The material, if soft, is hammered into a thin plate, and 



* Practical Hygiene, p. 203. 

t Ibid., p. 205. 

% Analyse des Matieres Alimentaires et Recherche de leurs Falsifications, 1S94, p. 695. 



900 FOOD INSPECTION AND ANALYSIS. 

2^ grams are weighed out, transferred to a 250-cc. flask, and dissolved 
in 7 to 8 cc. of concentrated nitric acid. Evaporate to dryness on the 
sand-bath, add 10 drops of nitric acid and 50 cc. of boiling water, cool, 
and make up to 250 cc. with water. Let the residue settle and pour off 
through a filter 100 cc. of the clear, supernatant liquid, corresponding 
to I gram of the material. This contains the lead, while the tin is left 
behind in the residue, together with antimony if present. 

Add 10 cc. of a standard solution of potassium bichromate (7.13 grams 
to the liter) and shake. Each cubic centimeter of this standard solution 
is sufficient to precipitate 0.0 1 gram of lead. Allow the lead chromate 
formed to settle, and, if the solution is colorless, add 10 cc. more of the 
bichromate, or sufficient to be present in excess, as indicated by the yellow 
color. Filter, wash, and titrate the excess of bichromate with a standard 
iron solution, containing 57 grams of the double sulphate of iron and 
ammonia and 125 grams of sulphuric acid per liter. This iron solution 
should be kept under a layer of petroleum, and standardized against 
the potassium bichromate before use. 

Add, drop by drop, the iron solution to that containing the excess of 
bichromate. The color of the latter passes from pale green to bright 
green, when the chromate is completely reduced. Determine the end- 
point with a freshly prepared dilute solution of potassium ferricyanide, 
a drop of which is placed on a porcelain plate or tile in contact with a 
little of the solution titrated. A blue color is produced when the iron 
is present in excess. If the standard iron and bichromate solutions 
exactly correspond, i cc. of the iron solution is equivalent to 1% of lead, 
but the latter solution is usually a little weak. 

If M = number of cubic centimeters of iron solution necessary to 
reduce 10 cc. of the standard bichromate, 

I cc. of the iron solution = — . 

n 

If, now, r = number of cubic centimeters of iron solution necessary 
to reduce the excess of bichromate in the determination, and 5 = number 
of cubic centimeters of bichromate used, 

s r = per cent of lead in the alloy. 

Separation and Determination of Tin, Copper, Lead, and Zinc in 
Canned Goods. — Munson's Method.'^ — The contents of the can are 
* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 52. 



CANNED AND BOTTLED VEGETABLES, ETC. 901 

first evaporated to dn-ness, and from 10 to 15 cc. of concentrated sul- 
phuric acid or enough to carbonize are added to the dr}- residue contained 
in a porcelain evaporating-dish, which is ven.- gently heated over the flame 
till foaming ceases. Then ignite to an ash in a muffle, or carefully over 
the free flame, using a little nitric acid, if necessar}', for oxidation of the 
organic matter. Add 20 cc. of dilute hydrochloric acid, and evaporate 
over the water-bath to drj^ness. Wash the residue into a beaker, slightly 
acidify with hydrochloric acid, and saturate with hydrogen sulphide 
without previous filtration. Heat the beaker on the water-bath, and 
pass the contents through a filter. Wash the precipitate, which contains 
sulphides of tin, lead, and copper, if these metals are present, while if there 
is zinc, it is contained in the fikrate. The precipitate is fused with sodium 
hydroxide in a silver crucible for half an hour, to increase the solubilitv 
of the tin, which would otherwise be dissolved with difficulty. The 
fusion is boiled up with hot water, acidulated with hydrochloric acid, and 
transferred w-ithout filtering to a beaker, in which hydrogen sulphide 
is added to saturation. This precipitates the sulphides of tin, lead, and 
copper (if these metals are present). The sulphide precipitate is collected 
on a filter, and thoroughly washed with hot water, the washmgs being 
rejected. Pass through the filter several portions of boiUng ammonium 
sulphide, using about 50 cc. in all, or till aU the tin is dissolved. Precipi- 
tate the tin from the combined filtrate with hydrochloric acid, filter, 
wash, ignite, and weigh as stannic oxide. 

The residue left on the filter, after dissolving out the tin sulphide, is 
then dissolved by treatment with nitric acid, which is filtered, and to 
the filtrate and washings ammonia is added nearly to the point of neutral- 
ization. Then add ammonium acetate. Filter off any precipitate of 
iron that may be formed. The tiltrate is divided into two portions for 
determination of copper and lead. If lead is absent, determine the 
copper by titration with potassium cyanide* or electrol}i;ically (p. 608). 
Copper is rarely present in sufficient amount to be determined, unless 
used for greening the vegetables. If notable quantities of lead are present, 
the solution is made acid with acetic, and the lead precipitated therefrom 
with potassium chromate, collected on a tared filter, washed with water 
acidified with acetic acid, dried at 100° C, and weighed as lead chromate. 
Or determine the lead by color-tests, as on page 902. 

For the determination of zinc, the filtrate from the first hydrogen- 
sulphide residue is evaporated to a volume of about 60 cc, and treated 

* Sutton, Volumetric .Analysis, 8th ed., p. 204. 



902 FOOD INSPECTION AND ANALYSIS. 

with bromine water lo oxidize the iron, as well as any excess of hydrogen 
Bul])hide reniaininfj;, the excess of bromine is then boiled off, and a few 
drops of concciilraled fc-rric cliloride added, to make the solution distinctly 
yellow, if not already so. Nearly neutralize with ammonia, and precijji- 
tate the iron with nniinonium acetate. Filter, wash, acidify the filtrate 
witli ;mti( acid, and precipitate the zinc with hydrogen sulphide. 
Filter, wash, ignilc, and weigh ;is zinc oxide. 

The metals may be determined sei)arately, as follows: 

Determination of Tin.* - lOvaporate the contents of the can lo dry- 
ness, and ignili- in porcelain. Inise the ash with sodium hydroxide in a 
silver crucible, boil the fusion with several })ortions of water acidulated 
with hydrochloric acid, hlter, and ])recipitatc the tin from the acid solu- 
tion with hydrogen sulphide. Dissolve the washed ])recij)itate in ammo- 
nium sulphide, filler, and deposit I he tin dirc-ctly from this solution by 
electrolysis in the phitinum dish which contains it, using a current of 
0.5 ani|)ere and the electrolytic apparatus described (>'i i^age 608. 

Determination of Lead, espec ially a])plicable if lead is present in small 
amounts only. Hoil the suljjhated ash of the contents of the can (obtained 
as on page ()oi) with a solution of ammonium acetate, having an excess of 
anmionia. The tin, zinc, and iron remain insoluble, while the coi)per 
and lead are dissohed. JMlter, wash, and add a few drops of ])otassium 
cyanide to the hltrate, to prevent ])recipitalion of copjjcr when hydrogen 
sulphide is subsi-cpiently added. If the solution exceeds 40 cc, concen- 
trate to thai amount by evaporation, and transfer to a 50-cc. Nesslcr 
tube. Add hydrogen sulphide water, and make up to the mark. Com- 
pare the brown color im])arte(l by the lead suli)hide, with the colors 
obtained by treating with hydrogeii suljjhicle water in Nessler tul)es 
various measured amounts of a standard solution of lead acetate, made 
alkaline with ammonia. 

Determination of Copper. — (i) Ekclrolyllcally. — Ash the contents of 
the can as on page qoi. Wet the ash with concentrated nitric acid, add 
water, and boil Then make strongly alkaline with ammonia and fdtcr. 
Unless the filtrate is colored blue, cop])er is absent. Transfer the fdtrate 
to a bright tared ])latinum dish of 100 cc. capacity, neutralize with 
concentrated nitric acid, and add about 2 (.w in excess. Nearly fill the 
dish with water, and eleclrolyze with the apj)aratus described on page 
608, using a current of about 0.3 of an ampere. 

* HilRcr u. I.;il)aii(l, /tits, fiir Untersuch. Nahr. u. Genuss., II, p. 795; An. Rep. Mass. 
State Hoanl of Ilraltli, iScjy, j). ()25. 



CANNED AND BOTTLED VEGETABLES, ETC. 9a? 

(2) Colorime!rically.—Thm method is especially applicable for small 
amounts of cop[)er. The blue-colored ammoniacal solution of the ash, 
filtered as in (i), is transferred to a Nessler tube, and its color matched 
against the colors of a series of measured amounts of an ammoniacal 
standard solution of copper sulphate 

Determination of Nickel. — Boil the ash with water slightly acidified 
with liydrochloric acid, and without filtering, saturate with hydrogen 
suli^hide, thus precipitating out any copjjcr, tin, or lead. FiUer and wash. 
Zinc and nici<el, if present, are in the fiUrate. Hoil the filtrate to cxj^el 
the hydrogen sulphide, and add sodium carbonate till slightly alkaline. 
Add acetic acid without filtering till the precipitate produced by the 
alkaline carbonate is dissolved, and then add a considerable excess of 
acetic acid. The zinc is precipitated by passing hydrogen sulphide 
throL'gh the cold dilute solution, while the nickel is hekl in solution by 
the large excess of acetic acifl. Filter, and wash with hydrogen sulphide 
water, to- which a little ammonium acetate has been added. 

Make the filtrate alkaline with ammonia, precipitate the nickel with 
ammonium sulphide, filter, wash, ignite, and weigh as nickelous oxide. 

ANTISEPTICS IN CANNED lOODS. 

No class of food jjroducts stands so little in need of these added sub- 
stances to arrest fermentation as canned foods, if jjrojierly ijrejjared; 
but, as a matter of fact, the use of antiseptics in this connection is still 
jjracticcfl. Proiongcfj healing for a sufficient length of time to perfectly 
Sterilize the contents of a can is in some cases more or less detrimental 
to the appearance of the [product, so that for this reason, as well as to save 
time in "processing," and furthermore to increase the keej)ing fjualities 
of the goods after opening, many manufacturers resort to the use of arti- 
ficial chemical preservatives. So long as any well-founder! prejudice 
against j^reservatives exists, their use in canned or bottled foods should 
be unequivocally conrlemned, unless the cans or packages are distinctly 
labeled with the nature of the preservative and the extent to which it 
is employed. 

As in other foods, discrimination as to locality is apparently used on 
the part of manufacturers in shi[jping canned goods containing added 
preservatives, so that, as a matter of fact, in states where it is well under- 
stood that a vigilant enforcement of the [jure-foofl law prevails, we do 
not find as high a [percentage of canned foods with preservatives as in 
other states. With llie national law, preservatives are now less prevalent. 



904 FOOD INSPECTION AND ANALYSIS. 

Preservatives commonly employed in canned goods are salicylic, 
benzoic, and sulphurous acids, though the other familiar antiseptic agents 
may be used. In such foods as canned corn, while the purpose of sul- 
phurous aci 1 may be in part as a preservative, the primary object for 
its use is undoubtedly to bleach or whiten the product. 

The Bleaching of Corn by artificial means before canning is usually 
accomplished by boiling the corn with sulphite of soda, thus giving to 
the product an unnaturally white color. The practice seems to have been 
more in vogue ten years ago than at present, the popular taste now appar- 
ently preferring the natural rich yellow of fresh corn. 

Saccharin is claimed to possess antiseptic powers and is used in canned 
goods, but its primary purpose is as a sweetener. 

Beta-riaphthol is also said to be used as a preservative in canned 
goods, but has not been found by the author in any samples that have 
come to hill for analysis. 

Dstection of Preservatives. — Tests for salicylic or benzoic acid are 
most readily made in the residue from an ether extract of a portion of 
the acidified contents of the can or package, while formaldehyde and 
sulphurous acid are tested for in the earlier portions of the distillate, 
obtained by distilling a mixture of the acidified contents in water. 

If it is desired to systematically test for the various preservatives 
in the same sample, a convenient method of procedure is as fol- 
lows: 

Thoroughly mix 50 grams of the pulped sample with water in a 250- 
cc. graduated flask, make distinctly acid with dilute phosphoric acid, and 
fill to the mark with water. Transfer to a distilling-flask, and subject to 
distillation in a glycerin- or parafhn-bath, whereby the temperature is 
raised near the end of the distillation considerably above 100° C. 

Remove the first 30 cc. of the distillate, and divide into three equal 
portions, which are to be tested for formaldehyde, sulphurous acid, and 
beta-naphthol by the usual tests for these preservatives. 

Continue the distillation till the residue in the flask is nearly dr\', and 
transfer the remaining or larger portion of the distillate to a large separa- 
tory funnel. Acidify with dilute sulphuric or hydrochloric acid, and 
extract with ether or chloroform. 

Divide the ether or chloroform extract into three portions in as many 
evaporating-dishes, evaporate to dryness at low temperature, and make 
the appropriate tests on the three residues for salicylic acid, benzoic acid, 
and saccharin, as given in Chapters XVIII and XIX. 



C/INNED AND BOTTLED VEGETABLES, ETC. 905 

The residue left in the flask is then washed out and incinerated, and 
the ash examined for boric acid. 

"soaked goods." 

It has become quite common, especially in the case of peas, beans, 
and corn, to utilize for canning purposes those that have grown old and 
dried, after soaking them for a long time. The presence of soaked peas 
in the market is generally more common in years when there is a scarcity 
in the pea crop. By the process of soaking, dried and matured field corn 
may be softened to such an extent as to be substituted for green or sweet 
corn in the canned product. These goods, frequently sold at a very low 
price, under some such tempting name as "Choice Early June Peas," are 
entirely devoid of that succulent property so highly prized in the fresh 
goods, and are altogether so inferior in quality that their sale may justly 
be considered as fraudulent, unless their character is specified. In some 
states the law provides that such a product, to be legally sold, shall 
have plainly marked on the label of the can the words "Soaked Goods" 
in letters of prescribed size. 

Detection. — Methods of detecting soaked goods are distinctly physi- 
cal rather than chemical. The appearance and taste of the goods furnish 
in most cases an unmistakable clue to their nature. Soaked goods are 
entirely lacking in juiciness, and in the flavors so characteristic of the 
various vegetables, when gathered and canned before becoming dry. 
The process of soaking is also said to develop the growth of the rudi- 
mentary stem of the embryo in the dried pea and bean. Peas and beans 
of the soaked variety are almost entirely lacking in the green color of 
the fresh vegetables, unless the color has been artificially supplied. 

In all cases it will be found that the solid grains or kernels of the 
peas, beans, and corn that have once been dried, though softened by 
the process of soaking, have much less water than the grains of the cor- 
responding vegetables that were gathered while still soft and succulent. 

KETCHUPS AND TABLE SAUCES. 

These preparations vary widely in their character and composition, 
and, in the absence of standards fixed by law for each particular mixture, 
almost any food product may be included in its make-up, without laying it 
open to the charge of being aduherated. At the same time, in this class 
of condiments it is naturally expected that the ingredients used all have 
some food value, and in addition possess a certain degree of pungency 



9o6 FOOD INSPECTION AND ANALYS'S. 

CHEMICAL COMPOSITION OF KETCHUP, PICKLES, AND RELISHES.* 





Number 

of 
Analyses 


Refuse. 


Water. 


Protein. 


Fat. 


Total 
Carbo- 
hydrates 


Ash. 


Fuel 
Value 

per 
Pound. 


Tomato ketchup 


2 
2 


27.0 
19.0 


82.8 
86.4 

58.0 
42.3 

64.7 

52-4 
92.9 

93-8 
77-1 


1-5 
1.4 

I.I 

.8 

1-7 
1.4 

-5 
I.I 

-4 


.2 
.2 

27.6 
20.2 

25-9 
21.0 

-3 
-4 
.1 


12.3 
10-5 

II. 6 

8-5 

4-3 
3-5 
2.7 
4.0 
20.7 


3-2 

1-5 

1-7 
1.2 

3-4 

2-7 

3-6 

-7 

1-7 


265 

230 


Olives, green: 

Edible portion 

As purchased 

Olives, ripe: 

Edible portion 

As purchased 

Cucumber pickles 

Mixed pickles 

Spiced pickles 


1,400 
1,025 

1,205 

975 

70 

no 

395 



* U. S. Dept. of Agric, Office of Exp. Sta., Bui. 2S, p. 70. 

or distinctive flavor. In other word.s, inert materials used simply as 
"fillers" are, to say the least, out of place, even though they are not 
actually adulterants. 

Tomato Ketchup of the U, S, Standards, consists of the strained })ulp 
of boiled, fresh, ripe tomato mixed with various spices, either with or 
without the addition of sugar and vinegar. 

The ketchup of the housewife is made from varying recipes, all based 
on the above method of procedure; and while the commercial bottled 
ketchups should be made from materials quite as pure, it is often true, 
e.specially in the cheaper varieties, that the skins and refu.se of tomato- 
canning factories, pumpkin pulp, or apple pulp, form the basis of the 
product. Even with the use of these materials, when properly prepared, 
and before advanced fermentation has set in, with clean methods of 
handling, the product may not be unwholesome. It is, however, some- 
times the practice to allow the refuse and skins to accumulate through a 
whole tomato-canning season, storing them all in large vats, and working 
them up, after they have become badly fermented, for " fre.sh tomato 
ketchup." It is largely for this reason that antiseptics and coloring 
matters are so commonly employed in ketchup. f Salicylic acid, for- 
merly much used as a preservative of ketchup, has in the past few years 
given place to benzoate of soda. 

Bitting has shown that by using sound tomatoes and exercising 

t The writer has in his possession a circular from an Indiana commission merchant, 
advertising for sale tomato pulp of some twelve different grades for ketchup. Among them 
are listed the following: "100 bbls. of old goods, made partly from whole stock and partly 
waste, boiled down nearly to ketchup thickness; has preservaline in it; fine goods, but some 
of it is fermented; packed in good oak whiskey and wine barrels. Price $2.00 per bbl." 



CANNED AND BOTTLED VEGETABLES, ETC. 9° 7 

proper care in the process of manufacture, ketchup can be kept without 
a preservative.* Manufacturers arc themselves corroborating this. 

Coloring of Tomato Ketchup.— The practice of adding artificial dye- 
stuffs to ketchup is decreasing. Indeed the very brilliant scarlet and 
crimson hues sometimes given to the bottled ketchups on the market in 
no wise resemble the natural dull-red or brown color of the pure home- 
made article, in which the bright color of the fruit pulp is modified by 
the mixture of spices with which it is cooked. It is doubtless true that 
many manufacturers employ such inferior materials that unless some 
dyestuffs were added the result would be most unappetizing in appearance. 
Out of ninety-five samples of tomato ketchup examined in 1901 in 
Connecticut all but fifteen contained coal-tar colors.t 

Walnut Ketchup. — This is made up in a somewhat similar manner 
to tomato ketchup, excepting that instead of tomatoes, soft young walnuts 
are crushed and used as a basis. 

Chili Sauce is made up of a pulped mixture of tomatoes, red peppers, 
onions, vinegar, and various spices, differing from ketchup in that it 
contains the seeds and is not strained. In consistency it is heavier than 
ketchup. It is colored and preserved in much the same manner as 
ketchup. 

Table Sauces are composed of a large variety of materials of a more 
or less pronounced flavor or pungency, combined in a liquid prepara- 
tion usually of a more thin or watery consistency than the ketchups. 
The materials employed include mushrooms, onions, garlic, ground ancho- 
vies, tamarinds, spices, coriander and cardamom seeds, walnuts, vinegar, 
molasses, and even assafoetida. These bottled preparations are very 
rarely colored except with caramel, but sometimes contain antiseptics, 
especially salicylic and benzoic acids. 

The Acidity of ketchups and table sauces furnishes a ready means 
of comparison between different varieties, and is conveniently expressed 
in terms of acetic acid. 

To determine the acidity, titrate i gram of the diluted sample with 
tenth-normal sodium hydroxide, using phenolphthalein as an indicator. 

"225 bbls. new goods, made from waste; has benzoate of soda in it, packed in uncharred 
whiskey and wine barrels at $3.00 per bbl. net cash." "300 bbls. old goods, partly whole 
stock, partly waste, has salicylic acid in it; nice goods, etc. Price $2.00 per bbl." "400 
bbls. new goods, Jersey style; solid and good red color, fine quahty. Price $3.00 per bbl." 
With prices as low as the above quotations, it is difficult to see how a cheaper basis for ketchup 
stock than the above could be supplied. Even the pulp of pumpkin and of other inert vege- 
tables, alleged to be used as adulterants, would hardly be furnished so cheaply. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 119. 

fAn. Rep. Conn. Exp. Sta., 1901. 



9o8 FOOD INSPECTION AND ANALYSIS. 

Each cubic centimeter of the alkaU corresponds to 0.006 gram of acetic 

acid. 

Winton and Ogden * have found the acidity of tomato ketchups ex- 
amined by them to vary between the limits of 0.60 and 2.20 per cent, 
calculated as acetic acid, Chili sauce from 0.80 to 1.80 per cent, and 
various table sauces from 1.40 to 1.60 per cent. 

Examination of Table Sauces and Ketchups for Preservatives. — 
Extract a portion of the acid sample with ether or chloroform, which 
removes salicylic or benzoic acid or saccharin. If the sample is of thin 
or watery consistency, like most table sauces, the extraction can in most 
cases be readily effected in a separatory funnel, chloroform being in this 
case most convenient, since it sinks to the bottom. If ketchup or other 
thick syrupy substance is to be examined, it is almost impossible when 
shaking with ether or chloroform to avoid the formation of an annoying 
emulsion, which it is dif&cult to break up. For this reason the author 
prefers, in the case of ketchups and similar viscous fluids, to separate 
the extract by means of a centrifuge of the style shown in Fig. 11. A 
portion of the acid sample, say 75 cc, is shaken violently in a corked 
flask with 25 to 40 cc. of ether, and the mixture, usually in the form 
of an emulsion, is poured into two of the centrifuge tubes, so that they 
contain equal amounts and balance each other. They are then corked, 
placed in the shields of the centrifuge, and whirled from two to four 
minutes, or until ^^^he emulsion is broken up. At the end of this time 
it is usually found that the mixture is separated into three layers: first 
a watery layer at the bottom of the tube, then an almost solid layer of 
the viscous material above it, and finally the clear ether extract at the 
top. As a rule the separation is so complete that the tube may be 
inverted, and every drop of the clear ether layer may be decanted with- 
out filtration, so firmly does the solid middle layer hold in place in the 
tube. Indeed, a vigorous shake is usually necessary to dislodge it. 

If saccharin, as well as salicylic and benzoic acids are all to be looked 
for, the ether extract is divided into three portions, in as many evaporating- 
dishes, and the dried residue tested in the regular manner for the above 
. substances. 

Examination of Ketchups for Colors. — Proceed as in the case of 
jellies and jams. 

*An. Rep. Conn. Exp. Sta., 1901, p. 137. 



CANNED AND BOTTLED VEGETABLES, ETC. 909 

PICKLES. 

A large variety of vegetables and fruits are preserved in the form 
of pickles in vinegar, either with or without spices, and kept in wooden 
pails, stoneware pots, kegs, or sealed, wide-mouthed bottles. The con- 
tainers are not of necessity air-tight. The commoner vegetables are 
usually pickled without cooking, while with fruits, as in the case of 
peaches, pears, gooseberries, etc., they are usually cooked, or at least 
heated. 

Cucumber Pickles are the most common, and are prepared by soaking 
the fresh cucumbers in strong salt brine. They are then dried on frames, 
and afterwards treated with boiling vinegar, to which spices may or may 
not be added. Other vegetables pickled in similar manner, either sepa- 
rately or in mixture with cucumbers to form "mixed pickles" or "gher- 
kins," are cauliflower, bean pods, white cabbage, young walnuts, and 
onions. 

Such soft vegetables as young podded beans and beets are not treated 
with brine, but, after soaking in water, are directly treated v/ith vinegar. 
The vinegar used for the finest pickling is of the cider, wine, or malt 
variety. Cheaper varieties of pickles are put up in "white wine" or 
spirit vinegar. 

Mustard Pickles. — These differ from plain vinegar pickles in the 
character of the preserving medium, which in this case consists of a mix- 
ture of mustard and spices with the vinegar to form a thin paste. 

Piccalilli consists of a mixture in vinegar of various chopped vege- 
tables, such as cucumbers, cauliflower, green pickles, onions, green toma- 
toes, and various spices. 

Olives for pickling are picked before they have fully ripened, and the 
inherent bitter taste is removed by soaking in a solution of potash and 
lime. This is replaced by cold water, and finally the olives are trans- 
ferred to the medium in which they are bottled, which consists of salt 
brine, either with or without flavoring. The flavoring materials employed 
consist of such substances as fennel, coriander, laurel leaves, and occa- 
sionally vinegar. 

Capers. — These are the flower buds of the shrub Capparis spinosa, 
which are pickled in vinegar. Nasturtium seeds, when similarly pickled, 
possess a flavor much resembling capers, but their substitution for capers 
could readily be detected by their distinctive appearance, even if colored. 

Adulteration of Pickles. — Green pickles, such as cucumbers, are 



Qio FOOD INSPECTION /1ND /iN A LYSIS. 

not uncommonly colored artificially by copper salts, either through the 
addition of copper sulphate, as in the greening of peas, or by the use 
of copper vessels. This artificial greening is to be looked for also in such 
products as capers and olives.. 

For methods of detection and estimation of copper, see page 902. 
Pickles may be greened by boiling with much less harmful substances 
than copper salts, such, for example, as grape leaves, spinach, or parsley. 

Free Sulphuric Acid has been found in a number of cases in the vine- 
gar of pickles bought on the Massachusetts market. A pronounced 
test for chloride with nitrate of silver should not be attributed to free 
hydrochloric acid, since it may be and probably is due to the salt from 
the brine in which the pickles have been treated. 

Alum is sometimes added to the salt solution to produce hardness 
and crispness in pickles. A number of samples of cucumber pickles 
have been found by the author to contain alum. For its detection, fuse 
the ash of the pickles, if free from copper, in a platinum dish with sodium 
carbonate, extract with boiling water, filter, and add ammonium chlo- 
ride. A flocculent precipitate shows alum. 

Sodium Benzoate and Saccharine are frequently used in sweet pickles. 

Horseradish. — This condiment is prepared by grating the root of 
the perennial herb Nasturtium armoricia, and preserving in vinegar. 
It is very pungent and aromatic when first prepared, but by exposure to 
light and air quickly loses strength. Turnip, an occasional adulterant of 
grated horseradish, is best detected by the microscope. 

JAMS AND JELLIES. 

Jams or marmalades are prepared from the pulp of fruits, and jellies 
from the fruit juices. Both jams and jellies, to be considered of the highest 
degree of purity, should contain nothing but the fruit pulp or juice named 
on the label, mixed with pure cane sugar, and, in the case of jams, the 
further addition of spices and flavoring materials is permissible. 

For the manufacture of jam, the washed fruit, if of the kernel variety, 
is peeled, freed from cores, and sliced; if berries, they are simply stemmed; 
if stone fruits, they are peeled, freed from stones, and quartered. The 
material, properly prepared, is cooked with as much water as is necessary 
for boiling, and with the addition of an amount of sugar varying with 
different manufacturers. Some prefer to use equal parts of sugar and 
fruit, others one part sugar to two parts fruit. 

In the case of jelly, the fruit is cooked in a small amount of water 



C/tNNED ^ND BOTTLED l/EGETABLES, ETC. gri 

till soft, transferred to a bag or press, and the juice allowed to flow out 
spontaneously, or is squeezed out under pressure, according to the grade 
of jelly desired, the clearest and finest varieties being made from the 
juice that flows out naturally. This juice is then evaporated down with 
the addition of sugar to a density of from 30° to 32° Be., which is of the 
proper consistency to form a perfect jelly product after cooling, and, while 
still hot, is poured into the tumblers in which it is to be kept. Here, as 
in the case of jams, the amount of sugar varies, some using pound for 
pound, and others only half as much sugar as fruit. Some manufacturers 
clarify their jellies by mixing with the juice, while boiling, elutriated 
chalk, using a teaspoonful to each quart of juice. The impurities come 
to the surface with the chalk as a scum, and are skimmed off. This 
clarifying process is somewhat analogous to the defecation of sugar juices 
with lime, and is commonly carried out with apple jelly. 

The "jellying" or gelatinizing of the final product is due to the presence 
in the 'fruit juice of pectin, or so-called vegetable jelly (C32H40O284H2O) ; 
see page 276. 

The high content of added sugar in jelly, once thought to be essential 
for keeping it, is now no longer considered necessar}^, and much less sugar 
is at present added than formerly. The finest grade of apple jelly, for 
instance, is made without any added sugar whatever. 

In making the better grades of apple jelly, apple juice fresh from 
the press is run directly into the boiler or evaporator before any fermenta- 
tion has ensued, and gelatinized by concentration. If boiled cider is 
wanted instead of jelly, it is drawn off at an earlier stage than in the case 
of apple jelly. 

Composition of Known-purity Jellies and Jams. — In the tables on 
pp. 912 and 913, due to Tolman, ]Munson, and Bigelow,* are given 
results reached on the examination of the pure finished products, as well 
as on pure fruit juices and pulp used in their manufacture. 

Adulteration of Jams and Jellies. — As a matter of fact, a small percent- 
age of these products sold in the United States are honest prototypes of 
the home-made jams and jellies, which consist exclusively of the fruit 
specified on the label, in mixture with pure cane sugar. If we accept as 
a standard the product of the housewife, fully 90% of the commercial 
brands of these preparations would be found wanting. So great is the 
demand for cheap sweets of this variety, that the market is flooded with 
them at eight and ten cents per half-pound jar, when in reality abso- 

* Jour. Am. Chem. Soc. (1901), pp. 349-351* 



912 



FOOD INSPECTION AND ANALYSIS. 



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<pquOOCf^PL,pL,PH 



914 FOOD INSPECTION AND ANALYSIS. 

lutely pure goods cannot be produced at much less than twice that 
amount. 

The cheap substitutes are made up largely of apple juice and com- 
mercial glucose, sometimes containing no fruit whatever of the kind 
specified on the label. Sometimes an attempt is made to imitate the 
flavor by the addition of artificial fruit essences, but more often the same 
apple-glucose stock mixture of jelly, put out under a particular brand, 
serves to masquerade as damson, strawberry, raspberry, current, grape, 
etc., differing from each other only in color, but not as a rule in flavor. 
A variety of artificial colors are employed, mostly coal-tar dyes. To 
compensate for the lack of sweetness of the glucose, a minute quantity 
of one of the concentrated sweeteners, such as saccharin or dulcin, is some- 
times added. Besides artificial colors, antiseptic substances are occasion- 
aUy used, especiaUy salicylic and benzoic acids. 

All grades of apple stock are found in these preparations. A large 
source of supply is furnished by the parings and cores of canning estab- 
lishments, to say nothing of the refuse of these factories, such materials 
being boiled wi.h water, and the extract, variously colored to imitate the 
different fruits, being evaporated with commercial glucose. 

Adulterated Jelly. — While it is easy to make an excellent apple jelly 
by simple evaporation of the pure apple juice, even without the addition 
of sugar, it is impossible, or at least difficult, to obtain the proper degree 
of stiffness with a mixture of apple stock and commercial glucose. It is 
customary, in the manufacture of cheap jellies, therefore, to employ 
what is technically termed a " coagulator." Formerly sulphuric acid, 
sometimes with addition of alum was used, but at present phosphoric 
acid is preferred. Citric or tartaric acid is also used for this purpose, 
as well as to increase the acidity. About i% of the acid wifl cause the 
mass to gelatinize satisfactorily. 

The lowest grade of apple jelly is made from the exhausted pomace, 
left as a residue after pressing out the juice for cider. Such stock is com- 
monly mixed with water, and boiled down with glucose. Having been 
exhausted of its malic acid, pectose, and other soluble constituents, it 
lacks much of the flavor inherent in pure apple jelly. Various foreign 
gelatinizing agents are found in cheap jellies and preserves, such as 
starch, gelatin, and agar-agar. In the low-priced goods, starch paste 
has been employed. It should be remembered that starch exists in unripe 
apples, but hardly at all in the mature fruit, so that while mere traces oi 
starch in jelly may be due to the use of green apples, its presence in large 
amounts is undoubted evidence of the admixture of starch paste. 



CANNED AND BOTTLED {VEGETABLES, ETC. 915 

Adulterated Jams. — Most of the cheap jams and bottled preserves 
sold on the market, though reinforced with apple stock, do in reality 
contain masses of fruit and berries of the kind stipulated on the label, as 
even a casual megascopic examination will show. That such low-priced 
preparations really contain genuine fruit pulp is not to be wondered at. 
when it is considered that much of the virtue of this fruit has sometimes 
been previously extracted by boiling, to produce fruit juices for higher- 
priced goods. Or, as in the case of jams containing strawberries, rasp- 
berries, and other small fruits with seeds, the juice is apt to have been 
previously expressed for pure jellies, while the residues are afterwards 
worked up with apple stock for low-priced jams. Hence the presence of 
pure fruit stock, or genuine berry seeds and pulp in jams, is in itself no 
criterion of purity, and, furthermore, it is unnecessary to use hay seed and 
other alleged foreign seeds as adulterants of cheap jam. 

Copipound Goods. — Many states have a law legalizing the sale of 
"compound" goods, providing they are distinctly so labeled. In other 
states, as, for instance, Massachusetts, the label must plainly state the 
name and percentage of the ingredients. In either case the analyst must 
discriminate, in classifying the inferior or low-grade preparations, between 
those that are labeled in accordance with the law, and those that are not. 
Only those not properly labeled can in such cases be classed as adulter- 
ated within the meaning of the law. Where such a law prevails, probably 
no class of food-products is so extensively affected by it as the low-grade 
jams, preserves, and jellies. 

The restrictions as to labeling do not in all cases eliminate the element 
of deception. It is hardly justifiable, for example, to boldly label an 
alleged "currant jelly" which contains no currant, in the following man- 
ner: 

Fruit juice... 25% 

Cane sugar 14% 

Corn syrup 61% 

100% 

The use of the term "fruit juice" surely implies to the unsuspecting 
purchaser that so much pure currant juice has entered into the jelly, else- 
where labeled in large letters " Currant," whereas all the juice is apple, 
and no currant juice has been used. 

The following label is a type of those which discriminate between pure 
fruit and apple juice: 



91 6 FOOD INSPECTION AND ANALYSIS. 

Fruit 30% 

Com syrup 35% 

Granulated sugar 15% 

Apple juice 20% 

100% 

Composition of Cheaper Grades. — Out of 66 samples of jellies, jams, 
and preserves analyzed by Winton, Langley, and Ogden in Connecticut, 
the samples being purchased in that state,* 17 samples contained starch 
paste, 35 were artificially colored with coal-tar dyes, and 19 contained 
salicylic or benzoic acid. 

The following table has been compiled, showing the sugar content of 
some of the typical commercial jellies and jams analyzed in the laboratory 
of the Massachusetts State Board of Health. Nearly all of these were 
artificially colored, and found to contain little if any fruit, other than apple. 



JELLY 

Apple 

Currant A 

B 

Grape 

Peach 

Pineapple 

Raspberry 

JAM. 

Damson A 

B 

Apricot 

Quince 

Raspberry A 

B 

C 

Pineapple 

Strawberry A 

B 





Invert Polarization. 




Polariza- 






Per Cent 






Sucrose. 




At 20° C. 


At 87° C. 




+64.0 


+ 28.0 


+ 36.0 


26.8 


+ 29.2 


+ 20.0 


+ 36-4 


6.9 


+ 41-6 


+ 33-9 


+ 40.8 


5-7 


+ 62.0 


+ 34-4 


+ 46.0 


20.6 


+ 119. 8 


+ 108.8 


+ IIO.O 


8.2 


+ 114. 


+ 107.6 


+ IIO.O 


4-9 


+ 112. 


+ 92.0 


+ 93-6 


14.9 


+ 107.0 


+ 94-4 


+ S8.i 


9-3 


+ 95-2 


+ 90-9 


+ 83-6 


3-2 


+ 99.0 


+ 93-5 


+ 85-6 


4-1 


+ 49-6 


+ 43-6 


+ 42.0 


4-5 


+ 123.6 


+ 119-2 


+ 102.!; 


2.6 


+ 77-6 


+ 65-1 


+ 46-9 


9-3 


+ 66.0 


+ 29-5 


+ 37-2 


27.2 


+ 119. 8 


+ 108.8 


+ IIO.O 


8.2 


+ 41-8 


+ 21.3 


+32-6 


15-4 


+ 83.6 


+ 72.0 


+78.8 


8.7 



Per Cent 
Commer- 
cial 
Glucose. 



22.1 
22.3 
2^.0 
28.2 
67-4 
67-4 
57-4 

35-6 
51-2 
52-4 
25-7 
62.8 
28.7 
22.8 

67-4 
20.0 

48.3 



METHODS OF ANALYSIS. 

As in the case of canned goods, but little information is to be derived 
as to adulteration of jams, jellies, and preserves by the ordinary deter- 
minations of moisture, ash, and nitrogen, and these are rarely made by 
the pubhc analyst. 

Of considerable importance in this regard, however, are the sugar 
determinations, made with a view to ascertaining the varieties of sugar 

* An. Rep. Conn. E.xp. Sta., 1901, p. 130. 



CANNED AND BOTTLED VEGETABLES, ETC. 91; 

employed, as well as their approximate proportion in the products exam- 
ined. 

Total Solids. — Ten grams of the jam, which has been evenly pulped 
in a mor:ar, or 5 grams of the jelly, are weighed into a tared platinum 
dish, taking care to spread the sample as thinly as possible over the bot- 
tom of the dish, and dried to nearly a constant weight at 100°. Results 
yielded by this method, while sufficiently close for ordinary work, are not 
exact, due to the slight dehydration of the sugars. If extreme accuracy 
is required, dr>' in vacuo at 75° C, or in a McGill oven, page 586. 

Soluble and Insoluble Solids. — ^A weighed amount of the evenly pulped 
sample, say 25 grams, is vigorously shaken in a 500-cc. graduated flask 
wi.h water, preferably with the aid of a mechanical shaker, and, after 
filling lo the mark, is again shaken. The residue is allowed to settle, and 
the supernatant liquid is decanted through a fiker, and an aliquot portion 
of the filtrate, say 50 cc, is measured into a tared dish and evaporated to 
drjmess, dried at 100° to a constant weight, and weighed for soluble solids. 
Insoluble solids are calculated by difference. 

Ash, — The residue from the total solids is burnt at duU redness to an 
ash, cooled in a desiccator, and weighed. 

Nitrogen is determined by the Gunning or Kjeldahl method, page 69, 
in from 5 to 10 grams of the uniformly mixed sample. 

Determination of Sugars. — In products of the highest grade, wherein 
only cane sugar is employed, a large portion of the cane sugar 
is inverted in the process of boiling the jam or jelly, so that when the 
analyst examines it, he finds, as a rule, only a small amount of sucrose, 
and considerable invert sugar. It is possible, however, to calculate the 
amount of cane sugar originally employed, if such information is desir- 
able. It is further of interest to calculate, at least approximately, the 
percentage of commercial glucose, when present, especially in cases where 
the package contains a formula setting forth the amount of the various 
ingredients used. In such cases the analyst is naturally called upon to 
verify the formula, since a wide variation in percentage composition from 
the statement on the label would constitute an offense under some state 
laws. 

Polarization. — Use half the normal weight of the preserve or jelly for 
the Schmidt and Haensch instrument, viz., 13.024 grams in 100 cc. If 
fresh fruit or fruit juice is to be examined, use the full normal weight, 
26.048 grams. Clarify, before making up to the mark, with subacetate of 
lead and alumina cream (using 2 to 3 cc. of each clarifier), filter, and 



9i8 FOOD INSPECTION y4ND ANALYSIS. 

obtain the direct reading; then invert in the usual manner, and obtain 
the invert readings at 20° C, and in the water-jacketed tube at 87° C, 
proceeding in detail as directed under honey, p. 641. 

Calculation of Sugars. — Sucrose is determined by using Clerget's 
formula : 

sJ-i^, (X) 

142.66 

2 

This represents the sucrose actually present as such in the preserve 
or jelly, and not the amount originally used. If the latter is desired, it 
may be calculated from the formula, 

5--^ (.) 

42.66 — 

2 

where S' is the per cent of cane sugar originally used, and h is the invert 
reading at f of the normal solution. 

If, after inversion, the correct reading at 20° is found to be 12 or more 
to the left of the zero, it can be safely inferred that no appreciable amount 
of commercial glucose is present, and it is unnecessary to make a third 
reading at 87°, unless to confirm the fact. In such a case, with cane sugar 
alone present, the reading at 87° will not, of course, vary much from o. 

Invert Sugar.— In the absence of commercial glucose, the invert sugar 
is calculated as follows: 

(Sucrose— direct reading)io5. 3 
Invert sugar = , ... (3) 

42.66 — 
2 

or it may be determined directly from the copper reducing power. 

Any decided reading above zero at 87° is due to the presence of com- 
mercial glucose, and when the latter is present, it is impossible to deter- 
mine the invert sugar from the copper reduction or by formula No. 3. 
The following formula is proposed for calculating approximately the 
invert sugar from the polarization, in the presence of commercial glucose. 
While theoretically correct, the method is subject to practical limitations, 
which admit of only roughly approximate results in such mixtures as 
jelly or jam. It is perfectly accurate only in mixtures of sucrose, glu- 
cose, and invert sugar. 



CANNED AND BOTTLED VEGETABLES, ETC. 919 

/Reading due to glucose and\ /Invert reading\ 

_ \ inverted sucrose at /° / \ at /° / 

Invert sugar = -^ ^ ^ 105.3 (4) 

±(42.66 — 



These formulas, (3) and (4), serve at best to indicate the approximate 
amount of invert sugar present in the sample, resulting from the inver- 
sion of a portion of the original sucrose in the natural process of manu- 
facture of the jam or jelly, and not the total inverc sugar resulting from 
the inversion by the analyst of all the sucrose. 

The factor 105.3 is used, since, in the natural process of inversion, 100 
parts of sucrose become 105.3 parts of invert sugar. 

Example. — The invert sugar in the sample of apple jelly first on the 
list in the table on page 916 is calculated as follows: 

Invert reading at f (20°) = 28.0. 

Reading due to glucose at 2o° = .22iX 175 = 38.68. 

" '' " inverted sucrose at 20° = . 268 X —34= —9.1 1. 

(38.68 -9.11)- 28 
Invert sugar = ^^^ 105.3 

= 5-76%. 

Reducing Sugar by Copper Reduction.* — Five grams of the pre- 
serve or jelly (or 25 grams of the fresh fruit or fruit juice) are transferred 
to a 100 cc. graduated flask, clarified by the addition of 2 or 3 cc. each 
of subacetate of lead and alumina cream, made up to the mark, shaken, 
and filtered. An aliquot part of the filtrate is then measured into another 
100 cc. flask, and treated with enough of a saturated solution of sodium 
sulphate to precipitate the lead, after which it is made up to the mark and 
filtered. The amount of sugar solution measured off into the second flask 
is such that, when finally made up to 100 cc. as described, approximately 
I of 1% of reducing sugar is present, as roughly estimated by the total 
solids and polarizations. The reducing sugar is then determined in 
the filtrate as dextrose by Defren's method, page 594, or if Allihn's 
method is used (p. 608) the amount of reducing sugar present should 
approximate 1%. 

Commercial Glucose. — While it is impossible to determine the exact 
percentage of this substance in preserves and jellies, by reason of the 
varying composition of its component parts, it is quite feasible to approx- 
imate very closely to the amount present. Ind eed, this approximate 
* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 78. 



920 FOOD INSPECTION AND ANALYSIS. 

method of calculation, wherein glucose is treated as a chemical entity, 
has been found in practice to be much more close to the actual truth 
than results gained by methods wherein the copper reducing power enters 
as a factor, or methods for determining separately dextrin, maltose, and 
dextrose. Calculate the commercial glucose in jellies and jams exactly 
as in the case of honey, p. 642. 

Dextrin.* — If alcohol be added to a somewhat thick solution of the 
fruit product, a white turbidity is at once apparent, followed by the forma- 
tion of a thick gummy precipitate, if dextrin is present. In the absence 
of dextrin there is no turbidity, but a light flocculent precipitate. 

To determine the dextrin, dissolve f 10 grams of the sample in a loo-cc. 
flask; add 20 mg. of potassium fluoride, and then about one-quarter 
of a cake of compressed yeast. Allow the fermentation to proceed below 
25° C. for two or three hours to prevent excessive foaming, and then 
place in an incubator at a temperature of from 27° to 30° C. for five days. 
At the end of that time clarify with lead subacetate and alumina cream; 
make up to 100 cc. and polarize in a 200-mm. tube. A pure fruit jelly 
will show a rotation of not more than a few tenths of a degree either to 
the right or to the left. If a Schmidt and Haensch polariscope be used, 
and a 10% solution be polarized in a 200-mm. tube, the number of degrees 
read on the sugar scale of the instrument, multiplied by 0.8755, will give 
the percentage of dextrin, or the following formula may be used: 

Percentage of dextrin = - 



iqSXLXPF' 
in which 

C = degrees of circular rotation, 

V = volume in cubic centimeters of solution polarized, 

L = length of tube in centimeters, 

1^ = weight of sample in solution in grams. 

Determination of Tartaric Acid. J — To 100 cc. of the fruit juice 
add 2 cc. of glacial acetic acid, 2 or 3 drops of a 20% potassium 
acetate solution, and 15 grams of pure finely powdered potassium 
chloride; dissolve this by shaking, and then add 20 cc. of 96% 
alcohol. Then stir vigorously for one minute, rubbing the walls of the 

* Bur. of Chem., Bui. 65, p. 78. 

t Bigelow and McElroy, Jour. Am. Chem. Soc, 1893, 15, 668. 

X Halenke & Moslinger, Zeit. anal. Chem., 1895, 34, 283; Bur. of Chem., Bui. 65, p. 80. 



CANNED AND BOTTLED l^EGETABLES, ETC. 921 

beaker with the glass stirring- rod to start the crystallization of the potas- 
sium bitartrate. Allow to stand fifteen hours at room temperature. 
Filter, and wash the precipitate into a Gooch crucible with a thin asbestos 
felt, using the vacuum pump. Wash with a mixture of 15 grams 
of potassium chloride, 20 cc. of alcohol, and 100 cc. of water. The 
beaker is rinsed three times with a few cubic centimeters of this solution. 
The precipitate is also washed with a few cubic centimeters, but so that 
not more than 20 cc. in all of the wash solution is used. The precipitate 
and asbestos filter are washed back into the beaker, and heated to boiling. 
While still hot, the solution is titrated with decinormal alkali, using 
phenolphthalein as indicator. To the amount of alkali used must be 
added 15 cc. for the potassium bitartrate remaining dissolved in the 
solution. I cc. of decinormal alkali is equivalent to 0.0150 grams of 
tartaric acid. 

Determination of Citric Acid.* — Fifty cubic centimeters of the fruit 
solution is evaporated on the water-bath to a syrupy condition. To 
the residue add, very slowly at first, stirring constantly, 95% alcohol 
until no further precipitate is formed; 70 to 80 cc. are generally enough. 
Filter, and wash the residue with 95% alcohol. Evaporate the filtrate 
to eliminate the alcohol, take up the residue with a little water, and 
transfer to a graduated cylinder, making up to 10 cc. To 5 cc. of this 
solution, add half a cubic centimeter of glacial acetic acid, and to this 
add, drop by drop, a saturated solution of lead acetate. The presence 
of citric acid is shown by the appearance of a precipitate, which possesses 
the property of disappearing on being heated, and reappearing on cooling. 
In order to separate the citric acid from other acids, heat to boiling, filter, 
and wash with boiling water; then allow to cool, and the precipitate of 
lead citrate will re-form. This lead precipitate may be filtered off, 
washed with weak alcohol, dried, weighed, and the citric acid calculated. 
It is necessary that there shall be no tartaric acid present. If the tartaric 
acid has been estimated, any error on this account may be avoided by 
adding enough decinormal potash to neutralize the tartaric acid before 
the alcohol is added. 

Detection of Coloring Matter. — Boil white woolen cloth or worsted 
in a solution of the jelly or jam, acidified with hydrochloric acid, or with 
acid sulphate of potassium, according to Arata's method and test for 
the color on the dyed fabric by methods given in detail in Chapter XVII. 

* Moslinger, Zeit. Unter. Nahr. u. Genuss., 1899, 2, p. 93; U. S. Dept. of Agric, Bur. 
of Chem., Bui. 65, p. 80. 



92 2 FOOD INSPECTION AND ANALYSIS. 

Detection of Preservatives and Concentrated Sweeteners. — Extract an 
acid aqueous solution of the fruit product with ether or chloroform in 
a scparatorv funnel, and test for benzoic and salicylic acids and for sac- 
charin in the ether extract. If dulcin is suspected, extract with acetic 
ether. 

Detection of Starch.* — Heat an aqueous solution of the preserve 
or jelly nearly to the boiling point, and decolorize by the addition of several 
cubic centimeters of dilute sulphuric acid and afterwards permanganate 
of potassium. This treatment does not affect the starch, which is tested 
,for with iodine in the ordinary manner in the solution after cooling. In 
the clear filtrate from a boiled apple pulp solution, free from added starch, 
little or no darkening should occur on the addition of the iodine reagent. 
If, however, the reagent is added to the residue of the previously boiled 
pulp, the presence of starch inherent in the apple is usually recognized 
by the blue color produced thereon. 

The presence of any considerable added starch paste in a fruit prepa- 
ration is thus readily indicated by an intense blue color obtained by adding 
the iodine reagent to the filtrate (free from fruit pulp). 

Detection of Gelatin. — Robiiis Method.'f — Add to a thick aqueous 
solution of the preserve or jelly sufficient strong alcohol to precipitate 
the gelatin. Decant the supernatant liquid after settling, set aside part 
of the precipitate, and dissolve the remainder in water. Divide the latter 
solution in two parts, to one of which add, drop by drop, a fresh solution 
of tannin, which precipitates gelatin if present. To the remainder add 
picric acid solution, which in presence of gelatin forms a yellow precip- 
itate. The portion of the yellow precipitate set aside is transferred to 
a test tube, and heated over the flame w-ith a little quicklime. If gelatin 
is present, ammonia will be given off, apparent by the odor, and by fumes 
of ammonium chloride when a drop of hydrochloric acid on a glass rod 
is held at the mouth of the bottle. 

Leffmann and Beam's Method.! — Boil the sample with water, filter, 
and boil the filtrate with an excess of potassium bichromate. Cool, and 
add a few drops of sulphuric acid. A flocculent precipitate indicates gelatin. 

Detection of Agar Agar.§ — The jelly is heated with 5% sulphuric 
acid, a little potassium permanganate is added, and, after settling, the 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 81. 
t Girard et Dupre, Analyse des Matieres .\limentaires, p. 578. 
X Select Methods of Food Analysis, p. 324. 

§ Marpmann, Zeit. f. angew. Mikrosk, 1896, p. 260; U. S. Dept. of Agric, Bur. of 
Chem., Bui. 65, p. 81. 



CANNED AND BOTTLED yEGETABLES, ETC. 923 

sediment is examined by the microscope for diatoms, which will be found 
in large numbers if agar agar has been used. 

Detection of Apple Pulp. — A distinct clue to the presence of apple 
pulp in fruit preparations is often furnished by the characteristic apple 
odor given off when a small amount of the sample is heated to boiling 
with water in a test tube. Under such conditions, the apple odor is quite 
apparent, as distinguished from that of other fruits, especially if the 
apple is the chief fruit present, or predominates in the mixture. 

Apple pulp in fruit preserves, free from added starch, may usually 
be recognized by a microscopical examination, using iodine reagent. 
The cell contents of the pulp will show the characteristic blue color, 
undoubtedly due to portions of unconverted starch still remaining in 
them. 

Detection of Fruit Tissues under the Microscope. — It is a matter 
of some difficulty, by means of a microscopical examination, to identify 
with certainty the various fruits and vegetables that might be used in 
a jam or jelly as adulterants. The structural features of the common 
fruits, while possessing distinctive points of difference when examined 
separately and in the raw products, are so changed or broken down by 
the process of cooking, as to be with difficulty recognizable. The soft 
parenchyma which forms the main portion of the tissue of the fruit pulp 
is, as a rule, more or less disintegrated. 

In the case of some of the smaller fruits, as the currant and raspberry, 
the cuticles resist the cooking process to such an extent as to show charac- 
teristic fragments, often recognizable in preserves and jellies under the 
microscope. The seeds are highly characteristic. 

FRUIT JUICES. 

Sweet cider, orange juice, lime juice, grape juice, raspberry shrub, 
and the juices of various other fruits and berries, may be so prepared 
and sterilized as to keep without fermentation when bottled, and are 
so put up in considerable variety, either with or without the addition of 
sugar. 

Such preparations, if of the highest purity, should consist of the 
undiluted juices of these fruits, separated by pressure and carefully ster- 
ilized and bottled. They should contain no other fruit juice than that 
specified on their labels, and should be free from alcohol, added antisep- 
tics, or coloring matter, unless the label specifies the presence of the added 
foreign materials. The addition of pure cane sugar to such prepara- 



924 



FOOD INSPECTION AND ANALYSIS. 



tions as grape juice is allowable, as well as charging with carbon dioxide 
to form so-called carbonated drinks. 

The following analyses of pure fruit juices are taken from tables 
prepared by Winton, Ogden, and Mitchell, showing results on samples 
purchased in the Connecticut market, as well as on some samples made 
in the laboratory.* 



Solids. 



Acids 
Other 

than 
CO 2 as 
Citric. 



Cane 

Sugar. 



Invert 
Sugar. 



Polarization. 



Direct. 



After I Temper- 
ature 
C. 



Inver- 
sion. 



Invert 
Reading 
at 86° C. 



COMMERCIAL FRUIT 
JUICES. 

Blackberry 

Cherry 

Black currant 

Red currant 

Grape 

Lime fruit 

Orange 

Pineapple 

Plum 

Quince 

Black raspberry 

Strawberry 

MADE IN LABORA- 
TORY. 

Peach 

Red raspberry 

Blackberry 

Huckleberry 

Pineapple 



12.70 

9.41 

8.94 

IX. 40 

13.90 



0.65 
0.80 
2.41 
2.09 
0.91 
6.50 

2-44 
0.81 
1. 00 
0.99 
1.36 
0.99 



0-95 
1. 19 
1.22 
0.51 
0.68 



i-S 



0.0 
0.0 



5-4 
0.8 



0.6 
7-4 



7-1 

5-1 

0-3 

16.7 

7-8 
5-1 



8.6 

8.7 

16.7 

9.1 



-1-3 
-1-9 
-2.7 
— 2.1 
-6-5 



•5-0 
•2-3 
•1-5 



4.8 
■1.6 
-2.4 
-4.0 

4-7 



■1-3 
-1-9 
-2.7 
-2.1 

-6-5 
0.0 
■2.1 
-2.0 
■o. I 
■5-0 
-2-3 
■1-5 



■2.4 
-4-8 
■4.8 



29.0 
26.0 
26.0 
27.0 
25.0 

26.0 
26.0 
26.0 
25.0 
26.0 
26.0 



28.0 
26.0 
30.0 
30.0 
28.0 



0.0 

0.0 

— i.o 

-0.8 



Antiseptics found most commonly in these preparations are boric, 
salicylic, benzoic, and sulphurous acids. Beta-naphthol should also be 
looked for. For methods of separation and examination see Chapter XVIII. 

Unfermented Grape Juice has the following average composition : f 





Austria, 
Per Cent. 


California, 
Per Cent. 


Solid contents by spindle 
(Balling) 


21.62 
None 

.78 

.01 

19.62 

.61 

•03 

-37 
-02 


20.60 
None 
-53 
-03 
19-15 
-59 
.07 
.19 
.04 


Alcohol 


Total acid (as tartaric) 

Volatile acid 


Grape sugar 


Cream of tartar 


Free tartaric acid 


Ash 


Phosphoric acid 





* An. Rep. Conn. Exp. Sta., 1899, p. 136. 



t California Exp. Sta., Bui. 130. 



CANNED AND BOTTLED VEGETABLES, ETC. 



925 



Grape juice is prepared by sterilizing at a temperature of 80° the 
juice expressed from the crushed grapes, filtering by means of a press 
or otherwise, and sealing in carefully sterilized bottles. After bottling, 
a final sterilization is conducted at a temperature 5° below the first. 
Bottled grape juices are rarely carbonated. 

Bottled Sweet Cider. — ^The composition of pure, freshly expressed 
apple juice is shown by the following table of analyses by Browne:* 



specific 
Gravity, 



Solids. 



Invert 
Sugar. 



Su- 
crose. 



Total 
Sugar. 



Total 
Sugar 
after 
Inver- 
sion. 



Free 
Malic 
Acid. 



Ash. 



Unde- 
ter- 
mined 
(Pectin, 
etc.). 



Left- 
handed 
Rotation 
Degrees 
Ventzke 
400 mm. 
Tube. 



Red astrachan 

Early harvest 

Yellow transparent 

Sweet bough 

Baldwin, green. . . . 

' ' ripe 

Ben Davis 



1-0532 
1-0552 
1.0502 
I . 0498 
1.0488 
1.0736 
1-0539 



12.78 
13.29 
II. 71 
11.87 
11.36 
16.82 
12.77 



.87 


3- 


-49 


3- 


-03 


2. 


.61 


3- 


.96 


I. 


-97 


7- 


.11 


3- 



10.50 

11.46 
10.14 
10.69 

8-59 
15.02 
10.96 



10.69 
XI. 67 
10.24 
10.85 
8.68 

15-39 
II. 16 



1. 14 
0.90 
0.86 
o.io 
1.24 
0.67 
0.46 



0-37 
0.28 

0.27 



0.77 

0.65 

0.44 



0.31 

0.26 

0.28 



0.87 

1.07 



23.72 
24.32 

39-40 
36.16 

49.00 



Bottled sweet cider, properly steriHzed, should not differ materially 
from the fresh juice, and should contain no alcohol. 

Salicylic acid is the antiseptic most commonly found in sweet bottled 
ciders examined by the writer. 

Lime or Lemon Juice. — This, according to the U. S. Pharmacopoeia, 
should consist of the freshly expressed juice of the ripe fruit of Citrus 
limonum (Risso), natural order of Rutaceae. Our supply of both lemons 
and limes comes chiefly from the West Indies and the Mediterranean. 
Both varieties of the genus Citrus are used indiscriminately for furnish- 
ing commercial lime juice, though strictly speaking, only that of the 
lemon is recognized in the Pharmacopoeia. The juice is sharply acid, 
and is largely composed of citric acid (about 7%), gum, sugar (3 to 
4 per cent), and inorganic salts from 2 to 2^ per cent. It also usually 
contains a little lemon oil from the rind. According to the pharmacopoeia, 
lemon juice (Limonis succus) should conform to the following require- 
ments : 

"Specific gravity: not less than 1.030 at 15° C. 

"it has an acid reaction upon litmus paper, due to the presence of 
about 7% of citric acid. 



* Penn. Dept. Agric, Bui. 58, p. 29. 



926 FOOD INSPECTION /iND ANALYSIS. 

"On evaporating 100 grams of the juice to dryness, and igniting the 
residue, not more than 0.5 gram of ash should remain." 

Of thirty samples of commercial lime juice examined in the Massa- 
chusetts State Board of Health laboratory, representing fifteen brands, 
all were deficient in citric acid, containing from 1.92 to 4.15 per cent, 
thus showing that these preparations are frequently watered. Fifteen 
were found to contain salicylic acid, seven had sulphurous acid, while 
two contained both these preservatives. Several were found colored 
with coal-tar dyes. 

One sample examined by the author, purporting to be a "pure West 
Indian Lime Juice, triple refined," proved to be a mixture of hydrochloric 
and salicylic acids, colored with a coal-tar dye, and contained no lime 
juice whatever. 

Acidity of lime juice is obtained by titrating 6.8 cc. of the sample 
against tenth-normal sodium hydroxide with phenolphthalein. The num- 
ber of cubic centimeters of the standard alkali required, divided by 10, 
gives the per cent of citric acid present. 

FRUIT SYRUPS. 

Two classes of these preparations are on the market, one for use in 
soda-fountains, and one for "family trade," intended as a basis for 
sweetened drinks to be diluted with water and sugar. Some are made 
exclusively from pure fruit pulp and sugar, sterilized by heating and put 
up in tightly sealed bottles, while others of the cheaper variety are more 
apt to be entirely artificial both in color and in flavor, deriving the latter 
principally from the wide variety of artificial fruit essences now available. 
Commercial glucose is a frequent ingredient. The same classes of coal- 
tar dyes and antiseptics are found in these preparations as in the other 
fruit products. Fruit syrups are frequently found to contain such 
materials as gum arable and quillaia, or soapbark, used both for a 
thickener, and to give a "bead" or froth when used in soda water, and 
in connection with carbonated drinks. 

For purposes of comparison with such fruit-pulp preparations as 
may come to the analyst for examination, he is referred to the analysis 
of fruits found on page 274. 



CASS ED ASD BOTTLED l^EGt TABLES, ETC. 927 



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Unters. Xahr. Genuss., 8, 1904, p. 36. 
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Xahr. Genuss., 8. 1904, p. 544. 
Beythien, A., u. Bohrisch, P. Ueber amerikanisches getrocknetes Obst. Zeits. 

Unters. Xahr. Genuss., 5, 1902, p. 401. 
Beitrage zur Untersuchung imd Beurteilimg des Citronensaftes. Zeits. Unters. 

Xahr. Genuss., 9, 1905, p. 449. 

• Ueber geschwefeltes Dorrobst. Zeits. Unters. Xahr. Genuss., 6, 1903, p. 355. 

Beythien, A., Bohrisch, P., u. Hempel, H. Ueber die Zusammensetzimg der 1905 -er 

Citronensafte. Zeits. Unters. Xahr. Genuss., 11, 1906, p. 651. 
BiGELOW, W. D., and Gore, H. C. Studies on Peaches. U. S. Dept of Agric, Bur. 

of Chem., Bui. 97. 

Ripening of Oranges. Jour -\m. Chem. Soc, 29, 1907, p. 767. 

• Study of Apple Marc. Jour. .\m. Chem. Soc, 28, 1906, p. 200. 

BiGELOw, W. D., Gore, H. C, and Howard, B. J. Studies on Apples. U. S. Dept. 

of Agric, Bur. of Chem., Bui. 94. 

Growth and Ripening of Persimmons. Jour. Am. Chem. Soc, 28, 1906. p. 688. 

BlOLETTi, F. T., and dal Piaz, A. M. Presenation of Unfermented Grape Must. 

Cal. Exp. Sta. Bui. 130. 
Bitting, A. W. Experiments on the Spoilage of Tomato Ketchup. U. S. Dept. of 

Agric, Bur. of Chem., Bui. 119. 
BoDiiER. R.. and Moor, C. G. On Copper in Peas. Analyst, 22, 1897, p. 141. 
B05ELEY. L. R. The Analysis of Marmalade. Anal\^t, 2^, 1898, p. 123. 
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Agriculture, Bui. 58. Jour. Am. Chem. Soc, 23, 1901, p. 869. 
BuDDEN, E. R., and Hardy, H. Colorimetric Estimation of Lead, Copper, Tin, and 

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BuTTEN-BERG. Hempel, Thaaqim. Luhrig. JrcKEN.\CK, B.ATER, et al. Fruchtsaft- 

Statistik, 1906. Zeits Unters. Xahr. Genuss., 12, 1906, p. 721. 



928 FOOD INSPECTION JND ANALYSIS. 

Chace, E. M., Tolman, L. M., and Munson, L. S. Chemical Composition of Some 

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Chem. Soc, 19, 1897, p. 733. 
Farnsteiner, K. Ueber organisch gebundene Schweflige Saure in Nahrungsmitteln. 

Zeits. Unters. Nahr. Genuss., 7, 1904, p. 449. 
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Marmeladen. Zeits. Unters. Nahr. Genuss., 15, 1908, p. 144. 
Formenti, C, u. Aristide, S. Zusammensetzung italienischer Tomatensafte. Zeits. 

Unters. Nahr. Genuss., 12, 1906, p. 283. 
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Halmi, J. Ueber ungarische Fruchtsafte, etc. Zeits. Unters, Nahr. Genuss., 15, 1908, 

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HiLGAR, A., u. Laband, L. Ueber electrolytische Abscheidung von Kupfer Zink und 

Zinn aus Konserven. Zeits. Unters. Nahr. Genuss., 2, 1899, p. 795. 
HiLTNER, R. S. A Rapid Method for the Analysis of Tin and Terne Plate. Wes- 
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Husmann, G. C. Manufacture and Preservation of Unfermented Grape Must. U. S. 

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Fruchtsyrupe. Zeits Unters. Nahr. Genuss., 8, 1904, p. 548. 
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8, 1904, p. 10. 
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Zeits. Unters. Nahr. Genuss., 8, 1904, p. 26. 
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8, 1904, p. 675. 
Krzizan, R., u. Plahl, W. 1905-er Himbeersafte und-syrupe bohmischer Herkunft. 

Zeits. Unters. Nahr. Genuss., 11, 1906, p. 205. 
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Jellies, Jams and Extracts.) North Dak. Exp. Sta., Buls. 53 and 57. 
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Unters. Nahr. Genuss., 13, 1907, p. 5. 
■ Beitrage zur Untersuchung und Beurteilung von Fruchtsaften. Zeits. Unters. 

Nahr. Genuss., 11, 1906, p. 212. 
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Zur Kenntnis des Citronensaftes. Zeits. Unters. Nahr. Genuss., 11, 1906, p. 441. 

LuHRiG, Beythien, Juckenack u. Baier. Fruchtsaftstatistik, 1905. Zeits. Unters 

Nahr. Genuss., 10, 1905, p. 713. 
Macfarlane, T. Unfermented Grape Juice. Can. Inl. Rev. Dept., Bui. 82. 



CANNED AND BOTTLED VEGETABLES, ETC. 929 

McElroy, K. p., and Bigelow, W. D. Canned Vegetables. U. S. Dept. of Agric, 

Div. of Chem., Bui. 13, part 8. 
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Am. Chem. Soc, 25, 1903, p. 242. 
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Genuss., 15, 1908, p. 595. 
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Himbeeren. Zeits. Unters. Nahr. Genuss., 6, 1903, p. 447. 
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22, 1900, p. 582. 
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Carolina. North Car. Exp. Sta., Bui. 165. 



INDEX 



Abbe refractometer, loo, io8 
construction, 109 
influence of temperature, no 
manipulation, 109 
Abrastoi, 8,37 
Absinthe, 754 
Acetanilifle in vanilla extract, 858 

tests for, 859 
Acetyl value, 497 
Achroodextrine, 575 
Acid fuchsin, 797 
Acids, fatty, 481, 484, 499, 500 
of acetic series, 471 
of linoleic series, 472 
of oleic series, 472 
mineral, in vinegar, 766, 767 
organic, 47 
Ackermann and Steinmann's table for 

alcohol from refraction, 715 
Ackermann's table for extract from refrac- 
tion, 721 
Adams' fat method, 134 
"Aerated" butter, 540 
Agar agar, in jelly, 914, 922 
Aging of liquors, 731, 732 
Albumin, acid, 44 
alkali, 44 

determination in milk, 146 
of muscle, 211 
preparation of, 263 
Albuminoids, 42 
Albumins, 41, 297 
Albumose, 44, 45 
Alcohol, detection, 657 

determination, 658 

by distillation, 658 
by ebulioscope, 675 
by evaporation, 660 
from refraction, 715 
from specific gravity, 658, 659 
in malt liquors, 715 
extract of spices, 470 
methyl-, 749, 869 
preparation of, 730 
stills, 659 
tables, 661-674 



Alcoholic beverages, 653, 654. See also 
Liquors, 
references on, 756 
state control of. 654 
toxic effect of, 655 
fermentation, 653 
Aldehydes, determination, 745 
Ale, 709, 712. See alscj Beer. 
Aleurone, 90 

Alkaloidal nitrogen, 40, 46 
Alkaloids, proof of absence of, 726 
Alkanna tincture, 92 
Allantoin, 299 

Allen-Marquardt method for fusel oil, 747 
Allihn's sugar method, 608 

tables, 609 
Allspice, 420 

adulteration, 424 
composition of, 420 
microscopical structure. 422 
standard, 424 
tannin in, 421 
Almond extract, 873 

adulteration of, 875 
alcohol in, 877 
benzaldehyde in, 874, 875 
hydrocyanic acid in, 874, 

877 
nitro benzol in, 876 
standards, 874 
meal, 358 
Almonds, bitter, oil of, 873, 874 
Alum in baking powder, 333, 344 
in bread, 326 
in flour, 315 
in pickles, 910 
Alumina, determination of, 344 
Aluminum salts in baking powder, 344 
in cream of tartar, 344 
Amagat and Jean's refractometer, 100 
Amides, 45 

in milk, 147 
Amid.) niir.jgen determination, 74, 147 

in wheat, 299 
Amino acids, 40, 45 
Ammonia, determination, 74 

931 



932 



INDEX. 



Ammonia, in baking powder, 346 
in foods, 40, 46 
in milk, 147 
Ammonium fluoride, 835 
Amthor test for caramel 752 
Amylodextrin, 575 
Amyloid, 91, q2 
Analyst, functions of, 3, 4 
Angostura, 754 
Anilin orange in milk, 177 
Animal diastase, 284 
Anise extract, standards, 880 

oil, standards, 880 
Annatto in butter, 536, 537 

in milk, 175, 177 

tests for, 789 
Antiseptics, see preservatives 
Apparatus, 20 

Apple essence, imitation, 884, 885 
Apple juice, 680 
Apples, composition of, 274, 275 
Araban, 285, 288 
Arabinose, 285, 288 
Arata's color test, 794 
Army rations, 257 
Arsenic detection and determination, 75, 76 

compounds in colors, 783 

Gutzeit test for, 632 

in beer, 713, 728 

in vinegar, 778 

Marsh apparatus, 75 
Artificial colors, 780 

fruit essences, 884, 885 
sweeteners, 842 

references on, 847 
Asaprol, 837 

Asbestos fiber, preparation of, 594, 598 
Ash analysis, scheme for, 301 
determination of, 6i 
of food, 47 
Asparagin, 45, 299 
Auramin, 782 

Babcock asbestos milk fat method, 135 

milk solids method, 134 
centrifugal fat method, 136 
milk formuhc, 153 
test bottles, 138 
Baier and Neuman's test for sucrose in milk, 

197 
Baking powders, 332 

adulteration of, 334 
alum, ^7,7,, 334 
methods of analysis, 336 
phosphate, 334 
tartrate, 332 



Balances, 20 

Bamihl test for gluten, 322 
Banana essence, artificial, 884, 885 
Barium compounds in colors, 782 
Bark as an adulterant, 428 
Barley, 271, 272 
ash, 302 

microscopy of, 309 
proteins, 300 
starch, 281 
Basic colors, 793, 796 
Baudouin's sesame oil test, 519 
Beading oil, 738 
Beans, 272, 388 

Beaume and Brix scales compared, 617-620 
Bechi's cottonseed oil test, 517 
Beckman's test for glucose in honey, 641 
Beef, composition of, 213 

cuts of, 213 

stearin, microscopical structure, 558 

tallow 529 
Beer, 707 

acids in, 724 

adulteration of, 711 

alcohol in, 715 

aloes in, 727 

arsenic in, 713, 728 

ash of, 714 

bitter principles of, 726 

bock-, 709 

brewing of, 708 

carbon dioxide in, 726 

chiretta in, 711, 727 

composition of, 709 

degree of fermentation of, 724 

dextrin in, 724 

extract gravity of, 722 

extract in, 715 

specific gravity method, 72a 
refractometer method, 722 

gentian bitter in, 711, 727 

glucose in, 710 

glycerin in, 724 

lager-, 70S 

methods of analysis, 714 

phosphoric acid in, 725 

preservatives in, 713, 729 

proteins of, 725 

fjuassiin in, 711, 727 

references on, 756 

schenk-, 708 

standards, 711 

temperance-, 714 

varieties of, 708 

uno-, 714 

weiss-, 709 



INDEX. 



933 



Beer, worl, 708 

fi;ravity of, 722 
Beeswax, 64^5 

rcfractomeler rca-.'liiig of, (^^i^ 
Beet (color), 788 

sugar, 569 
Bellier's peanut oil test, 524 
Benches, 15 
Benedictine, 754 
Benzaldehyde, 874, 875 

artilkial, 874 
in almond extract, 875 
Benzoic acid, 827 

detection of, 828 
determination, 8^0 
in milk, 180 
Betaine, 45, 299 
Beta-naphthol, 8_^7 
Bigelow and Mt I'llroy's cane-sugar method, 

192 
Bilberry (color), 788 
Birotation, 584, 639 
Biscuit, gluten, 358 

soja bean, 358 
Bisulphites as preservatives, 833 
Bitter almonds, oil of, 873 
Biuret reaction, 41 
Blackberry (color), 788 
Blarez test for fluorides, 835 
Blast pum]), 19 

Blue colors, 783, 784, 786, 792, 810 
"Blown" cans, 890 
Bock-beer, 709 
"Boiled" butter, 540 
Bombay mace, 467 
Bomb calorimeter, 47 
Bomer's phytosterol acetate test, 507 
Borax, 821 
Boric acid, 821 

detection, 182, 184, 822 
determination, 821, 823 
in butter, 538 
in meat, 220,232 
in milk, 182, 184 
Bourbon whiskey, 732, 734, 737 
Brandy, 739 

adulteration of, 741 
composition of, 739 
"drops," 649 
methods of analysis, 745 
new, 740 
potable, 740 
standards, 740 
Bread, 317, 323 

acidity of, 325 
adulteration of, 326 



Bread, alum in, 326 

baking of, 323 

composition of, 324, 325 

fat in, 326 
Breakfast cereals, 352 
Brewing beer, 708 
Brie cheese, 202 

Brix scale compared with Heaum(', 617-620 
Bromination oil test, 494 
Bromine absorption of oils, 492 
Jirown and Duvel's method for moisture in 

grain, 278 
Brown colors, 784, 786, 808 

sugar, 568 
Browne's method for dextrin in honey, 640 
test for invert sugar in honey, 642 
Brucke's glycogen method, 236 

reagent, 236 
Buckwheat, 271 

ash of, 302 

lomposition of, 271, 272 
flour, 313 

microscopy of, 311 
Burgundy wine, artificial, 692 
Butter, 201, 529 

adulteration of, 535 

annatto in, 536 

ash in, 534 

azo colors in, 536, 537 

boric acid in, 538 

carrotin in, 536 

casein in, 534, 551 

coloring in, 535 

composition of, 530 

distinction from oleomargarine and 
process butter, 546 

effects of feeding, 531 

fat, composition of, 530 
standard, 535 

fat in, 533, 534 

fdled, 540 

foam test, 549 

formaldehyde in, 539 

glucose in, 539 

methods of analysis, 531 

microscopical examination of, 552 

milk test, 550 

preservatives in, 538 

references on, 562 

renovated, 540 

salicylic acid in, 539 

salt in, 534 

standard, 535 

sulphurous acid in, 539 

water in, 531 

turmeric in, 536 



934 



INDEX. 



Butter, Waterhouse test, 550 

Butterine, 541 

Butterine oil, 522 

Butyro-refractometer, 100, loi 
critical line of, 106 
limits of butter readings, 547 
manipulation, 102 
oil readings on, 478, 479 
olive and cottonseed oil readings, 514 
sliding scale for, icj 
special thermometer for, 549 
table of equivalent refractive indices, 

104, 105 
temperature variation of reading, 

107 
testing scale, 104 

Caffeine, 372 

determination of, 373, 384 
in cocoa, 400 
Caffeol, 379 

Caffetannic acid, 379, 382 
Cake, 327 

Calcium carbonate crystals, 90 
oxalate crystals, 90 
sucrate, 196 
California wines, 688 
Calorie, 47, 48 
Calorimeter, bomb, 47 
oil, 495 
respiration, 2 
Camembert cheese, 202 
Camera, 96 
Canada balsam, 86 
Candy, see confectionery 

standard, 645 
Cane sugar, 566 

ash of, 567 
composition of, 568 
detection of, 585 

in milk, 197 
determination of, 

by copper reduction, 590, 612 
by polarimetry, 586, 614 
in cereals, 295 
inversion of, 588, 589 
manufacture of, 567 
methods of analysis, 585 
moisture in, 586 
quotient of purity, 586 
refining, 570 
test for, 585 
Canned food, 887 

antiseptics in, 903 
composition of, 889 
decomposition of, 890 



Canned food, impurities in, 890 

metallic impurities in, 892 
method of canning, 888 
methods of analysis, 889 
references on, 927 
Canned fruits, 887, 889 
meats, 22 

vegetables, 887, 889 
Cans, detection of spoiled, 890 

gases from spoiled, 891 
Capers, 909 
Capsicin, 440 
Capsicums, 439 
Caramel, 790 

in distilled liquors, 752 
in milk, 176, 177 
in vanilla extract, 860 
in vinegar, 777 
Carbohydrates, 46, 47, 74, 279 

of cereals. 279, 295 
of eggs, 263 
Carbon dioxide in baking chemicals, 336 
in beer, 726 
in yeast, 330 
Carnin, 211 
Carrot (color), 789 
Casein, 43, 125, 126 

determination in milk, 145 
Caseose, 44 

in cheese, 203 
in milk, 146 
Casoid flour, 358 
Cassia, 424 

adulteration of, 428 
buds, 425 

composition of, 422 
extract, standards, 830 
microscopical structure, 426 
oil, 425, 880 

standards, 880 
standard, 428 
Cayenne, 439 

adulteration of, 443 
coal-tar colors in, 444 
colors in, 444 
composition of, 441 
microscopical structure, 441 
mineral aduheranls in, 444 
oil of, 440 
redw^ood in, 444 
standard, 443 
Cazeneuve's color scheme, 705, 706 
Celery seed extract, standards, 880 

oil, standards, 880 
Cellulose, 47, 285 
Centrifuge, milk-fat, 136, 137 



INDEX. 



935 



Centrifuge, universal, 25 

Cereal products, microscopy of, 305 

Cereals, 271 

ash of, 302 
breakfast foods, 352 
cane sugar in, 295 
carbohdyrates of, 279 

separation of, 295 
composition of, 271 
crude fiber in, 277, 296 
dextrin in, 295 
hemicelluloses in, 296 
methods of proximate analysis, 276 
pentosans in, 285, 296 
proteins of, 296 
references on, 361 
starch determination in, 283, 296 
Chace's citral method, 866 
Champagne, 687 
Chaptalizing, 693 
Chartreuse, 754 
Cheddar cheese, 202 
Cheese, 201 

adulteration of, 203 
amides in, 206 
ammonia in, 206 
ash in, 204 
composition of, 201 
cream, 203 
lactic acid in, 207 
fat in, 204, 207 
filled, 203 

methods of analysis, 204 
milk sugar in, 207 
nitrogen compounds of, 205 
paranuclein in, 206 
peptones in, 206 
proteins in, 205 
sampling, 204 
skimmed milk, 203 
standards, 203 
varieties of, 202 
water in, 204 
whole milk, 203 
Chicory, 386, 388, 389 
Chili sauce, 907 
Chilton cheese, 202 
Chiretta, 727 
Chlor iodide of zinc, 91 
Chloral hydrate, 93 
Chlorine in vegetable substances, 305 
Chocolate, see cocoa, 
milk, 397 

composition of, 397 
sucrose and lactose in, 399 
Cholesterol, 502 



Cholesterol, crystallizations of, 504 
determination of, 503 
distinction from phytosterol,S03 
separation of, 503 
Cholin, 45, 299 
Chromate of lead, 647, 
Chromogenic bacteria, 130 
Cider, 678 

adulteraton of, 682 
ash of, 682 
composition of, 679 
fermented, 680 
malic acid in, 683 
manufacture of, 678 
methods of, analysis, 696 
references on, 757 
sweet, 925 
vinegar, 760, 771 
watering of, 682 
yeast in, 678 
Cinnamon, 424 

composition of, 425, 426 
extract, 881 

microscopical structure of, 426 
oil, standards, 881 
standard, 428 
Citral, 871 

determination, 866 
Citric acid in fruit products, 921 
in lime juice, 925 
in milk, 126, 127 
Citronellal, 872 
Citronella oil, 871, 872 
Clams, 256 
Claret wine, 687 
Clarifying reagents in microscopy, 92 

in sugar analysis, 586,614 
Clerget's formula, 588 
Clove extract, 881 

oil, 881 
Cloves, 412 

adulteration of, 418 
composition of, 414 
cocoanut shells in, 419 
exhausted, 418 
microscopical structure, 416 
oil of, 881 
standard, 418 
stems, 417 
tannin in, 415 
Clupein, 43 
Coal-tar colors, 791 

acid, 796 
allowed, 792 
Arata's test, 794 
basic, 793 



936 



INDEX. 



Coal-tar colors, classification, 791, 798, 800 
detection of, 793 
double dyeing method, 794 
dyeing wool by, 793 
extraction by amyl alcohol, 

795 
identification of, 793, 797, 

799> 803 
in milk, 177 
in sausages, 239 
Rota's scheme for, 797 
Sostegni and Carpentieri's 

color test, 794 
separation with ether, 796 
Cochineal, 790 

in sausages, 238 
Cocoa, 392, 393 

adulteration of, 402 
alkali in, 403 
ash of, 396 
butter, 393, 529 
caffeine in, 400 
composition of, 393 
foreign fat in, 402 
manufacture of, 393 
methods of, analysis, 398 
microscopical structure, 403 
nibs, 394, 402 
nitrogeneous bodies in, 396 
pentosans in, 396 
references on, 406 
shells, 394, 395, 405 
standards, 402 
starch in, 394, 395, 399, 405 
sugar in, 399, 405 
theobromine in, 396, 400 
Cocoanut oil, 528 
pulp, 528 
shells, 419 
Coffee, 379 

adulteration of, 384 

ash of, 380, 382 

caffeine in, 380, 384 

caffetannic acid in, 379, 382 

caffeol in, 379 

chicory in, 388, 389 

coloring of, 384 

composition of, 379, 380, 381 

essential oil of, 379 

fat in, 579 

glazing of, 385 

hygienic, 390 

methods of analysis, 382 

microscopical structure, 386 

"pellets," 384 

references on, 406 



Coffee, standards for, 384 
starch in, 386 
substitutes, 392 
Cognac, 739. See also Brandy. 

oil, 741 
Collagen, 42, 211 
Collodion silk, 705 
Colorimeter, Schreiner's, 77 
Colorometric analysis, 77 
Colors, artificial, 780 

acid fuchsin 797 
allowed, 792 

animal, 790 

arsenic compounds, 783 

barium compounds, 782 

basic, 793 

blue, 783, 784, 786, 792, 810 

brown, 784, 786, 808 

caramel, 790 

chromate of lead, 791 

coal tar, 791, 792, 793 

cochineal, 790 

copper compounds, 782 

cudbear, 789 

extraction of, by immiscible sol- 
vents, 795 

fuchsin, 798 

green, 783, 784, 785, 792, 810 

harmless, 782, 784 

identification of, 793, 797, 803 

indigo, 790, 810 

injurious, 782, 783 

in butter, 535 

in cayenne, 444 

in confectionery, 649, 786 

in jams and jellies, 921 

in ketchup, 908 

in milk, 174-177 

in mustard, 460 

in sugar, 590 

lead chromate, 647, 782 

lead compounds, 782 

logwood, 789 

mercury compounds, 783 

mineral, 790 

non-injurious, 782, 784 

orange, 785, 792, 806 

orchil, 789 

Prussian blue, 790, 792, 810 

reagents for identifying, 812 

red, 783, 784, 788 

references on, 813 

Rota's scheme for, 797 

separation by solvents, 795 

toxic effect of, 781 

turmeric, 789 



INDEX. 



937 



Colors, ultramarine blue, 791, 810 
vegetable, 787, 789, 795 
violet, 784, 786, 810 
wool dyeing, 793, 794 
yellow, 783, 785, 788, 792, 806 
Colostrum, 1 29 

Commercial glucose. See Glucose 
Compressed yeast, 328 
Conalbumin, 262 
Concentrated foods, 257 
Condensed milk, 186 

as a milk adulterant, 186 
ash of, 189 

cane sugar in, 191, 192 
composition of, 187 
fat in, 189, 191, 192 
milk sugar in, 190 
methods of analysis, i88 
proteins in, 190, 192 
solids of, 188 
standards for, 188 
Confectionery, 645 

adulteration of, 645 
alcohol in, 649 
arsenic in, 649 
cane sugar in, 648 
colors in, 645, 647 
dextrin in, 648 
glucose in, 648 
invert sugar in, 648 
lead chromate in, 647 
methods of analysis, 646 
mineral adulterants, 646 
paraffin in, 647 
starch in, 648 
Connective tissue 211, 
Copper salts, 897 

determination of, 900, 902 
in vinegar, 778 
Copra oil, 5 28 
Cordials, 754 

analysis of, 755 
composition of, 755 
Corky tissue, 89 
Corn, 271, 272 

ash of, 302 

bleaching of canned, 904 
composition of, 271, 272 
microscopical structure, 309 
oil, 521 

sitosterol in, 522 
proteins of, 300 
starch, 281 
syrup, 575 
Cornelison's butter color test, 537 
Corning of meat, 219 



Cottonseed, 516 

oil, 516 

standards for, 517 
tests for, 517 
stearin, 517 
Cotton's cane sugar method 185 
Coumarin, 853 

determination, 858 
microscopical structure, 860 
Crampton and Simon's caramel test, 752 

palm oil tests, 542 
Cream, 193 

adulteration of, 195 
cheese, 202 
evaporated, 195 
gelatin in, 195 
methods of analysis, 194 
standards for, 195 
sucrate of lime in, 196 
test scale, 194 
viscogen in, 196 
Cream of tartar, 336 

in wine, 702 

methods of analysis, 336 
Creatin, 46, 211 
Creatinin, 46, 211 
Creme de menthe, 755 
Creme de Noyau, 754 
Crude fiber, 277 

in cereals, 296 
Crustaceans, 256 
Crystals, plant, 90 
Cucumber pickles, 909 
Cudbear, 789 
Cuprammonia, 93 
Curafoa, 754 
Curcuma, 450 
Curcumin, 451 

Curd tests in butter, 551, 552, 553 
Curing meat, 219 
Currant (color), 788 
Curry powder, 450 
Custard powders, 270 

Dakota mustard, 460 

Date stones, 390 

Decker-Kunze method for theobromine and 

caffeine, 400 
Defren-O'SuUivan sugar method, 150, 594 
Defren's sugar tables, 595 
Desiccated egg, 268 
Deutyro-albumose, 44, 45 
Dextrin, 575 

determination of, 
in cereals, 295 
in glucose, 632 



938 



INDEX. 



Dextrin, determination of, in honey, 640 

in molasses, 624 
Dextrose, 573 

detemiination of, 591, 593, 594, 

598 

Diastase, animal, 284 

in malt extract, 729 
starch methods, 283 

Diabetic foods, 357 

analyses, 358 

Dietetics, references on, 49 

Distilled liquors, 730 

aldehydes in, 745 
analytical methods, 745 
caramel in, 752 
color tests 752, 753 
esters in, 745 
extract in, 745 
furfural in, 746 
fusel oil in, 746 
methyl alcohol in, 749 
opalescence test, 753 
references on, 758 

Doolittle and Woodruff theine method, 373 

Doolittle butter color test, 537 

Double dilution sugar method, 149 

Dough, expansion of, 317 

Drains, 17 

Dry wines, 696 

Dry yeast, 328 

Dubois's salicylic acid method, 826 

Dubosc's saccharimeter, 583 

Dulcin, 845 

determination, 846 

Dupre's color method, 705 
color tests 752, 753 

Dvorkovitsch theine method, 373 

Ebulioscope, 675 
Edam cheese, 202 
Edestan, 44 
Edestin, 299, 300 
Eggs, 261 

ash of, 264 

carbohydrates of, 263 

cold storage, 267 

composition of, 264, 265 

desiccated, 268 

fat of, 264 

frozen, 268 

lecithin determination, 265 

methods of analysis, 265 

opened, 268 

physical examination of, 267 

preservation of, 266 

proteins of, 262 



Eggs, references on, 270 
substitutes for, 269 
waterglass as a preservative, 266 
weights of, 264 
white of, 262 
yolk of, 263 
Elaidin oil test, 499 
Elastin, 211 

Elderberry (color), 788 
Electrolytic apparatus, 608 
Elm bark, 428 
Emergency rations, 257 
Ergot, 313 
Erythrodextrin, 575 
Essential oils, 871, 880 
Esters, in distilled liquors, 745 

in imitation flavors, 884 
Ether, ethyl, preparation of absolute, 66 
petroleum, preparation of, for a sol- 
vent, 66 
Eucasin, 158 
Eugenol, 412 
Ewe's milk, 127 
Exhausted cloves, 418 
ginger, 450 
lea leaves, 375 
vanilla beans, 851 
Exhaust i)ump, 20 
Extraction with immiscible solvents, 68- 

volatile solvents, 63 
Extractor, Johnson, 55 
Soxhlct, 63 

"Faints," 732 

Farinaceous infants' foods, 356 

Fat globules, 90 

Fat of food, 39 

of meat, 226, 227 
Fats, edible, 471. See also Oils, 
filtering, 473 
measuring, 473 
melting point of, 4S0 
methods of analysis, 473 
microscopical examination of, 510 
jjaralTin in, 510 
references on, 561 
weighing, 473 
Fatty acids, 499 

constants of, 500 
insoluble, 485 
solidifying point of, 500 
soluble, 484 
volatile, 841 
Fehling processes, 590 

gravimetric, 150, 59J 
volumetric, 150, 591 



INDEX. 



939 



Fehling's solution, 591 

equivalents of, 592 
Fermentation, acetic, 759 

alcoholic, 653 
lactic, 129 

proteolytic, 158, 202 
Fermented liquors, 678 
Fcser's lactoscope, 163 
Fibrin, 125 

Fibro vascular tissue, 88 
Fibroin, 42 
Filled cheese, 203 
Fish, analyses of, 255 

preservatives in, 257 
Flavoring extracts, 849 

references on, 886 
Flesh foods, 211 

references on, 258 
Fletcher and Allen's tannin method, 371 
Floor, I 5 
P"k)ur, 311 

absorption test of, 317 

acidity in, 320 

adulteration of, 314 

alcohol soluble protein in, 320 

alum in, 315 

baking tests of, 317 

bleaching of, 315 

detection, 321 
cold water extract of, 320 
cok)r test of, 317 
composition of, 312 
damaged, 313 
dough test of, 317 
fineness of, 316 
gluten in, 319, 322 
inspection, 316 
iodine number of fat of, 320 
methods of analysis, 316 
nitrites in, 321 

proximate constituents of, 319 
salt soluble protein in, 320 
Fluoborates, 835, 836 
Fluorides, 835 

detection of, 835 
Fluosilicates, 835, 836 
"Foam" test for butter, 549 
Food adulteration, 5 

analysis, commercial, 3 

from dietetic standpoint, 2 
general methods, 4 
references on, 79 
concentrated, 257 
economy, references on, 49 
inspection, 3, 6 

references on, 11 



Food misbranding, 6 

nature and composition of, 39 
official control of, i 

references on, 11 
standards, 4 
Fore milk, 128 
Foreshots, 732 
Formaldehyde, 818 

detection of, 180, 820 
determination of, 181, 819,. 

821 
in eggs, 268 
in milk, 178 
Fortified wine, 685, 690 

Fresenius' method for colors in pastes, 3 so- 
Frozen milk, test for, 129 

meat, 239 
Fructose, d-, 574 

1-5-, 574 
Fruit, 274 

candied, 646 

composition of, 274 

essences, artificial, 883, 885 

juices, 923, 924 

methods of proximate analvsis, 276 

products, 887 

references on, 927 
references on, 361 
sugar. See Levulose. 
sugar-coated, 646 
sugar in, 566 
syrups, 926 

tissues under the microscope, 923 
Fuchsin, 796 
Fuel value, 47 
Funnel, jacketted, 474 

separatory, 67, 68 
Furfural, 285 

determination, 746 
in distilled liquors, 746 
in vinegar, 777 
Fusel oil, 731 

detection, 746 
determination, 747 
Fustic, 788 

Game, composition of, 216 
Gases, in spoiled cans, 891 
Geerlig's table for dry substances in sugar 

products, 615 
Geissler's carbon dioxide apparatus, 337 
Gelatin, 42, 211 

in cream, 195 

in meat, 231 
Gerber's milk centrifuge, 136 
Gill and Hatch's oil calorimeter, 495 



940 



INDEX. 



Gin, 744 
Ginger, 445 

adulteration of, 450 

V)lack, 446 

cold water extract of, 448 

composition of, 446, 447 

exhausted, 447 

extract, standards, 881 

liming of, 446 

microscopical structure of, 449 

oil of, 446, 

standards, 881 

root, 445 

standard, 450 

white, 446 
Gliadin, 42, 298, 299 
Globulins, 42, 297 
Globulose, 44 
Glucin, 847 
Glucose, 575 

arsenic in, 632 
composition of, 576 

d-, 573_ 

determination of, in honey, 637, 641 
in jams and jel- 
lies, 919 
in molasses, 621 
dextrin in, 632 
healthfulness of, 576 
in beer, 710, 712 
in butter, 539 
methods of analysis, 630 
standards for, 576 
test for, 632, 641 
Glucoses, 565 
Glutelins, 42 
Gluten, 298, 299 

Bamihl's lest for, 322 
biscuit, 358 
determination of, 319 
Gluten flour, 357, 358 
Glutenin, 42, 298, 300 
Glycerin in vanilla extract, 860 

in wine, 703 
Glycerin jelly, 86 
Glycogen, 212 

detection, 235 
determination, 236 
Glycoproteins, 43 
Goat's milk, 127 
Gooch's boric acid method, 824 
Graham flour, 312 
Grain, moisture in, 278 
Grape juice, 924 
Grape sugar. See Dextrose 
Grape sugar, standard, 574 



Gray's method for water in butter, 532 
Green colors, 783, 784, 785, 792, 810 
Groats, 312 
Gruyere cheese, 202 
Gums, 89 

Gunning-Arnold nitrogen method, 432 
Gunning nitrogen methods, 69, 71 
Gutzeit arsenic test, 632 

Haemoglobins, 43 

Halphen cottonseed oii test, 518 

Hanus' iodine absorption method, 491 

Hefelmann's Bombay mace test, 467 

Hehner and Richmond's milk formula, 151 

Hehner's method for insoluble fatty acids, 486 

Heidenhain's tartaric acid method, 340 

Hemicellulose, 285, 296 

Hess and Prescott vanillin and coumarin 

method, 858 
Hetero-albumose, 44, 45 
Hiltner's citral method, 868 
Hilyer's benzoic acid method, 831 
Histones, 43 
Hock wine, 689 
Hoffmeister's schalchen, 64 
Holstein cows, milk from, 162 
Honey, 633 

adulteration of, 636 

American, 634 

analysis of, 639 

Canadian, 634 

composition of, 633, 635, 636 

dextro-rotatory, 635, 636 

European, 633 

gelatin in, 639 

glucose in, 637, 641, 642 

Hawaiian, 634 

invert sugar in, 638, 642 

methods of analysis, 639 
Honeydew, 636, 642 
Hoods, 16 
Hops, 708 

substitutes, 710 
Hordein, 42 

Horseflesh, characteristics of, 234 
composition of, 222 
detection of, 235, 237 
glycogen in, 235 . 
Horseradish, 910 
Hortvet method for acids in wine, 701 

number, of maple products, 628 
of vinegar, 768 

and West's benzaldehyde method, 

875 
rose oil method, 883 
spice oil method, 882 



INDEX. 



941 



Hort\-et and Wests wintergreen oil method, 

87S 
Howard's test for gums in ice cream, 201 

volatile oil method, 865 
Hiibl's iodine absorption method, 4S7 
Human milk, 127 

Hungarian red pepper, 459, 441, 442 
Hunt's iodine reagent. 492 | 

Hydrocyanic acid, S74, 877 
Hydrometer. 55 
H\-poxanthin, 211 

Ice cream, 19S 

anaKtical methods, 199 
detection of thickeners, 200 
fat in, 199 
gelatine in, 201 
preservatives in, 201 
standards, 199 
starch in, 201 
Imitation coffee, 3S4 
Immersion refractometer, ico, in 
adjustment of scale, 113 
distilled water readings on, 113 
in\-estigation of small quantities of 
solutions by, 115 
of solutions excluded from air 
by, 115 
milk examination by, 166 1 

scale readings compared with n^^ 

116 I 

solutions standardized by, 120 1 

references on, 122 

temperature corrections for, 121 I 

Incinerator, 173 
Indicators, 38 

Indices of refraction, 105. 116 
Indigo, 790, 811 
Indol, 92 
Infants' foods, 354 

classification of, 355 
cold water extract of, 360 
composition of, 356 
methods of analysis, 359 
microscopical examination of, 

360 
preparation of. 355 
Inosite, 276 

Inspection of foods, 3, 5. 6. 9 
flour, 316 
Uquors, 655 
milk, 159 
Inulin. 276 
In\-ands' foods, 354. See 

Foods. 
Inversion, 588 



also Infants' 



Invert sugar, 589 

detection of, 589, 625, 642 
determination of, 589, 59S 
in honey, 63S, 642 

Iodine absorption of oils, 487. 491, 492 

Iodine in potassium iodide, 91 

Irish whiskey, 732, 734, 735 

Jams, 910 

adulteration of, 911, 915 

agar agar in. 922 

apple stock in, 914 

coagulator in, 914 

coloring matter in, 921 

composition of, 911. 913, 916 

dextrin in, 920 

gelatin in, 922 

glucose in. 919 

methods of analysis, 916 

polarization of, 917 

preser\atives in, 922 

starch in, 922 

sugars in, 917-919 
Jellies, see Jams 
Johnson extractor, 65 

Juckenack's lecithin phosphoric acid method, 
349 

Kenrick's tartaric acid method, 340 

Kephir. 159 

Keratins, 42 

Ketchups, 905 

colors in, 907 
preservatives in, 90S 

Kjeldahl nitrogen method, 72 

Knorr's carbon dioxide apparatus, 338 

Koelner's baking test. 317 

Koettstorfers saponification method, 486 

Konig and Karach's method for distinguish- 
ing honeydew and glucose, 642 

Koumis, 158 

Krober's table for pentosans and pentoses, 
288 

Laboratory benches, 15 

stain for, 16 

drains, 17 

equipment, 14. 15 

references on, t^S 

floor, 15 

hoods, 16 

Ughting, 15 

location, 14 

sinks, 17 

ventilation, 15 
Lactalbumin, 125 



942 



INDEX. 



Lactaled infants' foods, 356 
Lactoglobulin, 125 
Lactometer, 131 
Lactoscope, 163 
Lactose, 125, 577 

Defren's table for, 595 

detection of, 625 

determination of, 593, 594, 998, 626 
in milk, 126, 127, 147 

Munson and Walker's table for, 

599 
Soxhlet's table for, 152 
Lager beer, 708 
Lamb, compoition of, 215 

cuts of, 215 
Landwehr's glycogen method, 236 
Lard, 554 

adulteration of, 556 
back, 554 

composition of, 554 
composition of as effected by feed- 
ing, 560 
"compound," 556 
constants of, 555 
iodine number, 559 
kettle rendered, 554 
leaf, 554 

microscopical examination of, 557 
neutral, 554 

oil, 555 

references on, 563 
standards, 556 
stearin, 555 
substitutes, 559 
Laurent's saccharimeter, 583 
La Wall and Bradshaw benzoic acid method, 

830 
Leach and Lythgoe method for malic value 
in maple products, 627 
methyl alcohol method, 749 
Lead chromate, 647, 782 

number, maple products, 628 

vinegar, 768 
salts of, 892, 896 

determination of, 899, 900, 902 
Leavening materials, 327,332 

references on, 364 
Lecitalbumin, ;3 
Lecithin, 46 

determination of, 265 
nucleovitellin, 43 
Lecithoproteins, 43 

Leffmann and Beam's method for volatile 
fatty acids, 482 
fat method, 49 
Legumelin, 41 



Legumes, 272 

ash of, 302 

Legumin, 42, 300 

Lemon extract, 861 

adulteration of, 862 
alcohol in, 866 
citral in, 866 
citric acid in, 870 
colors in, 869 
composition of, 863 
lemon oil in, 863, 864 
methods of analysis, 863 
methyl alcohol in, 869 
standard for, 86 r 
tartaric acid in, 870 
terpeneless, 862 
oil, terpeneless, 862 

Lemongrass oil, 863, 872 

Lemon juice, 925 

Lemon oil 861, 871 

determination of, S63, 864 
examination of, 870 

Lentils, 272 

Leucosin, 41, 299, 300 

Levallois' bromine absorption niethod, 

49.5 
Levulose, 574 

determination <if, 626, 640 
Liebig's meat extract, 242 
Lighting, 15 
Lignin, 94 
Lime, determination of, 303 

in baking powder, 345 
in spices, 410 
juice, 924 
sucrate of, 196 
water, in vinegar analysis, 765 
Liming of ginger, 446 
Limonene, 871 
Liqueurs, 754 

analysis of, 755 
Liquor inspection, 655 
Liquors, alcohol in, 658, 715 
ash of, 677 
distilled, 730 

methods of analysis, 745 
extract of, 677 
fermented, 678 
malt, 707 

methods of analysis, 714 
malted and non-malted, 712 
methods of analysis, 657 
preservatives in, 677 
specific gravity of, 657 
Lobster, composition of, 256 
Logwood, 789 



t 



INDEX. 



943 



Long fermentation haking lest, 318 

pepper, 438 
Lovibond tintometer, 77 
Lovventhal's tannin method, 370 
Low wines, 732 
Lythgoe's sucrose test for milk, 197 

Macaroni, 347 
Macassar mace, 46S 
Mace, 462, 465 

adulteration of, 466 
Bombay, 467 
composition of, 465 
Macassar, 468 

microscopical slriuiurc of, 466 
standard, 466 
Madeira wine, 687 
Maize. See Corn. 
Malaga wine, artificial, 692 
Malic acid in cider, 702 

in vinegar, 767 
in wine, 702 

value in maple products, 627 
Malt, 707 

extracts, 284, 729 
liquors, 707. See also Beer. 
substitutes, 710 
vinegar, 762 
Malting, 707 
Maltose, 574 

detection of, 625 
determination of, 594, 598 626 
Maple sap, 570 

sugar, 570. See also Maple syrup, 
syrup, 570 

adulteration of, 572 
ash of, 571, 572 
composition of, 571, 572 
Hortvet number of, 628 
lead number of, 628 
malic acid value, 627 
methods of analysis, 627 
moisture in, 627 
standards, 572 
Maraschino, 754 
Mare's milk, 127 
Marigold, 789 

Marpmann's color method, 239 
Marsh arsenic test, 75, 728 
test for caramel, 753 
Martin's color scheme, 535 
"Malerna" milk modifier, 157 
Maumene thermal test, 494 
Mayrhofer's glycogen method, 237 
McGiil's drying oven, 586 
Meat, 211 



Meat, antiseptics in, 220 

ash in, 225 

fjases, 211, 222, 22S, 231 

boric acid in, 232 

canned, 221 

canning of, 221 

colors in, 238 

composition of, 221 

cooking, effect of, 220 

corning of, 219 

curing of, 21 q 

extracts, 240 

acidity of, 253 
albumoses in, 250 
ash in, 249 
composition of, 242, 243, 

247 
creatin in, 244, 252 
creatinin in, 244, 252 
fat in, 249 
fluid, 241, 243, 244 
gelatin in, 253 
glycerol in, 254 
meat bases in, 252 
methods of analysis, 246 
nitrogen compounds of, 249, 

250 
peptones in, 251 
preservative''- in, 254 
proteoses in, 250 
solid, 241, 242, 244 
standards, 241 
xanthin bases in, 253 

fat, composition of, 226 
determination, 226 

gelatin determination, 231 

glycogen in, 236 

inspection, 217 

juices, 241, 245, 247, 24S 

manufactured, 218 

methods of analysis, 225 

nitrates in, 232 

nitrogen determination, 226 

nitrogenous bodies, separation of, 228 

peptones in, 251 

pickled, 218 

powders, 247, 248 

preservation of, 218 

preservatives in, 232 

proteins, coagulable, -.^31 

proteoses in, 231 

ptomaines in, 218 

refrigeration of, 219 

salicylic acid in, 233 

salted, 219 

smoked, 219 



944 



INDEX. 



Meat, standards of, 21S 

sulphurous acid in, 231 
unwholesome, 218 
water in, 225 
Melting point, 480 
Mercury compounds in colors, 783 
Metallic salts in canned goods, toxic effects 

of, 899 
Metaproteins, 44 

Methyl alcohol, detection of, 749, 869 
Micro-chemical reactions, 94 
Micro-polariscope, 84 
Microscope in food analysis, 81 

references on, 98 
reagents for, 90 
stand, 82 
Microscopical accessories, 84 
analysis, 81 
apparatus, 82 
diagnosis, 86 
reagents, 90 

analytical, 91 
clarifying, 92 
Microscopy of auar agar, 922 
allspice, 422 
arrowroot, 282 
barley, 309 

starch, 281 
bean, 388 

starch, 282 
buckwheat, 311, 437 

starch, 281 
butter, 552 
cassia 426 
cayenne, 441 
cereal products, 305 
chicory, 386 
cinnamon, 426 
cloves 416 
cocoa, 403 
cocoanut shells, 419 
coffee. 386 
corn, 309 
starch, 281 
date stones, 390 
fats, 510 
flour, 306, 322 
ginger, 449 
honey, 633 
jamsj 923 
jellies, 923 
lard, 557 
mace, 466 
milk, 124 
mustard, 458 
nutmeg, 464 



ISIicroscopy of oats, 309 

oat starch, 28 2 
oils, 510 

oleomargarine, 552 
olive stones, 436 
paprika, 441 
pea, 388 

starch, 282 
pepper, black, 433 
long, 439 
red, 441 
white, 433 
potato starch, 282 
rice, 310 

starch, 282 
rye, 308 

starch, 281 
sago, 283 
sawdust, 444 
starches, 280 
tapioca starch, 282 
tea, 378 
turmeric, 451 
wheat, 306 

starch, 281 
Micro-technique, 82 
Milk, 124 

acidity of, 124, 153 

adulteration of, 159 

alkalinity of ash, 198 

anilin orange in, 175, 177 

annatto m, 175, 176 

ash of, 127, 134 

ashing of, 134 

ass's, 127 

boiled milk, detection, 155 

boric acid in, 182 

calcium oxide in, 198 

calculation of proteins, 153 

caramel in, 176, 177 

carbonate in, 180, 182 

chocolate, 397 

citric acid in, 127 

coloring matter in, 174-177 

composition of, 124-126 

constants, 169 

ewe's, 127 

fat of, 127, 134 

fermentations of, i2y 

foods, prepared, 157 

fore milk, 128 

formaldehyde in, 178, i8i 

goat's, 127 

human. 127 

inspection, 159 

known purity, 169 



INDEX. 



945 



Milk, mare's, 127 

methods of analysis, 130, 163, 16;; 

microscopical appearance, 124 

modified, 155 

nitrogen compounds in, 125, 14:5 

powder, 157 

preservatives in, 177 

proteins of, 125, 145, 153 

records of analvsis of, 172 

references on, 20S 

ropy, 130 

sampler, 131 

serum, refraction of, 166, 167 

specific gravity of, 166, 167 

skimmed, 161 

sour, analysis of, 186 

souring of, 129 

standards, 160 

strippings, 128 

sucrate of lime in, iq6 

detection, 197, 198 

sugar, 125, 577 

determination of, 593, 594, 598 
determination of, in milk, 147, 

149^ 151 
systematic examination of, 130, 168 
total solids in, 133, 134 

calculation of, 151, 153, 154 
w'atering of, 161 
Milliau's cottonseed oil test, 518 
Millon's reaction, 41, 92 

reagent, 92 
Mill's bromine absorption method, 493 
Mineral colors, 790 
Mineral content of food, 47 
Mirbane, oil of, 875 
Mitchell's fusel oil method, 74S 
Modified milk, 155 
Mohler's test for benzoic acid, 829 
Moisture, determination of, 61 
Molasses, 567 

adulteration of, 621 

ashing of, 614, 624 

clarifying, 614 

composition of, 568 

glucose in, 621 

invert polarization at 87° C, 623 

methods of analysis, 613 

standard for, 621 

sucrose in, 614 

tin in, 625 

total solids in, 613 

vinegar, 763 
Mollusks, 256 
Mucoid protein, 127 
Munson and Walker sugar method, 151, 598 



Munson and Walker sugar table, 599 
Muscle albumin, 211 

fibers in meat, 211 
sugar, 212, 238 
Muscovado, 567, 568 
Mustard, 453 

adulteration of, 459 

ash of, 457 

black, 45j 

cake, 455 

coloring matter in, 460 

composition of, 455, 456 

Dakota, 460 

flour, 454 

methods of analysis, 457 

microscopical structure of, 458 

oil, fixed, 454, 525 

volatile, 453, 457 
pickles, 909 
prepared, 460 

adulteration of, 460 
composition of, 460, 461 
methods of analysis, 461 
sinalbin in, 454 

mustard oil, 453 
sinapin sulphocyanate, 457 
standard, 459 
starch in, 459 
turmeric in, 460 
volatile oil of, 453 
wheat in, 459 
white, 453 
Mutton, composition of, 215 
cuts of, 215 
tallow, 529 
Myosin, 42 

insoluble, 44 

Natural wine, 685 
Neufchatel cheese, 202 
Nickel salts, 899 

determination of, 903 
Niebel's glycogen method, 236 
Nitrates in food, 40, 46 

in watered milk, 168 
Nitrobenzol, 875, 876 
Nitrogen apparatus, 72, 73 

compounds in milk, 145 
determination of, 69, 73 
free extract, 54 
Nitrogenous bodies 

classification of, 40 
separation of, in cheese, 205 
in meat, 228 
in milk, 125, 126, 145 
Noodles, 347 



946 



INDEX. 



Notification, lo 
Noyau, 754 
Nuclein, 43 
Nucleoj)roteins, 43 
Nutmeg, 462, 463 

adulteration of, 464 

composition of, 462, 463 

extract, standards, 881 

Macassar, 465 

microscopical structure of, 464 

oil of, 463 

standard, 881 

standard, 464 
Nutrose, 158 
Nuts, composition of, 275 

Oats, 271 

analysis of, 271, 272 
ash of, 302 

microscopic structure, 300 
starch in, 282 
Oil cakes, effects on butter of feeding, 531 
lard of feeding, 560 
calorimeter, 495 
Oil, bitter almond, 873 
cassia, 425 
cloves, 881 
cocoanut, 528 
corn, 521 
cottonseed, 516 
ginger, 446 
lard, 555 
lemon, 861, 871 

terpeneless, 862 
lemongrass, 872 
mustard, fixed, 454, 525 

volatile, 453, 457 
nutmeg, 881 
oleo, 541 
olive, 511 — — (• /• 
orange, 873 
peanut, 522 
peppermint, 879 
poppy seed, 526 
rape, 520 
rosin, 527 
sesame, 519 
spearmint, 880 
sunflower, 526 
wintergreen, 878 
Oils, edible, 471. See also Fats 
acetyl value, 497 
bromine absorption of, 492 
bromination test, 494 
cholesterol in, 502, 503, 507 
composition of, 471, 472 



Oils, edible, constants of, 508, 509 
elaidin test, 499 
fatty acids in, 484, 499 
iodine absorption of, 487, 492 
judgment as to purity of, 473 
Maumene test, 494 
melting point, 480 
methods of analysis, 473 
microscopical examination, 510 
phytosterol in, 502, 503, 507 
Poienske number of, 483 
rancidity of, 473, 530 
references on, 561 
refractive index of, 477 
Reichert-Meissl number, 481 
saponification of, 472, 484, 486 
sitosterol in, 522 
specific gravity of, 474 

factors, 475 
thermal tests, 493 
titer test, 500 

unsaponifiable matter in, 501 
Valenta test, 499 
viscosity, of 477 
Oils, essential, 880 
Oleomargarine, 541 

adulteration of, 543 
coloring of, 542 
constants of, 544 
distinction from butter, 544, 546 
healthfulness of, 543 
manufacture of, 541 
microscopical examination, 552 
odor and taste, 545 
palm oil in, 542 
Zega's test for, 353 
Oleo oil, 541 
Olive, composition, 511 
Olive oil, 512 

adulteration of, 512, 515 
examination of, 515 
refraction of, 514 
standard, 513 
Olives, pickled, 909 
Olive stones, 436 
Orange colors, 785, 786, 806 
extract, 873 
oil, 873 

standards, 873 
terpeneless, 873 
Orchil, 789 

O'Sullivan-Defren sugar method, 150 
Ovalbumin, 262 
Oven, drying, 22 

McGill's 586 
Ovomucin, 262 



INDEX. 



947 



Ovomucoid, 263 
Oxygen absorbed, 415 

equivalent, 415 
Oxyhaemoglobin, 43 
Oysters, 257 

Palas rapcseed oil test, 521 
Paprika, 439 

added oil in, 445 
adulteration of, 444, 445 
composition of, 442 
methods of analysis, 445 
microscopical structure of, 441 
Paraffin in confectionery, 647 
in beeswax, 643 
in fats, 510 
in oleomargarine, 543 
Paranuclein, 206 
Parenchyma, 87 
Pastes, adulteration of, 349 

artificial colors in, 349 
edible, 347 
Italian, 347 

lecithin phosphoric acid in, 349 
methods of analysis, 349 
noodles, 347 
Patrick's method for water in butter, 531 

test for thickeners in ice cream, 
200 
Pea, composition, 272 
proteins of, 300 
starch of, 282 
Peanut oil, 522 

adulteration of, 523 
standards for, 522 
tests for, 523, 525 
Pear cider, 683 

essence, imitation, 884, 885 
Pectose, 93, 276 
Pekar's color test of flour, 317 
Pentosans, 285, 296 

determination of, 285, 296 
in cocoa products, 396 
table for, 288 
Pentose, 285, 296 
Pepper, 428 

adulteration of, 435 

black, 429 

buckwheat in, 437 

composition of, 430, 432 

dust, 436 

ether extract in, 410 

long, 438 

microscopical structure of, 433 

nitrogen in, 432 

in ether extract, 433 



Pepper, olive stones in, 436 
piperin in, 429 

determination of, 433 
red. See Cayenne and Paprika 
shells, 435 
standard, 435 
varieties of, 429 
white, 429 
Peppermint extract, 879 

composition of, 880 
standards, 879 
oil, 879 
Peptides, 45 
Peptones, 44 

in cheese, 202 
in meat, 211, 231 
in milk, 146 
Peter's test for benzoic acid, 829 
Perry, 683 
Persian berries, 788 
Petroleum ether, 66 
Phloroglucide, 286 
Phloroglucinol, 287 
Phosphate baking powders, t^t,^ 
Phosphoproteins, 43 
Phosphoric acid in baking chemicals, 346 

in beer, 725 
Phosphotungstic acid reaction, 45 
Photomicrography, 93 

camera for, 96 
Phytolacca 788 
Phytosterol, 502 

acetate test, 507 
crystallization of, 503 
determination of, 503 
distinction from cholesterol, 503 
separation of, 503 
Piccalilli, 909 
Pickled meats, 218 
Pickles, 909 

adulteration of, 909 
Pickling pump, 219 
Pimiento, 439, 442 

Pineapple essence, imitation, 884, 885 
Pioscope, 164 
Piperin, 429 

determination of, 433 
Piutti and Bentivoglio's method for colors 

in pastes, 351 
Plant crystals, 90 
Plasmon, 1 58 
Plastering, of wine, 692 
Platinum dishes, 61, 133, 134, 170 

counterweights for, 170 
Poisoned foods, 74 
Poivrette, 436 



948 



INDEX. 



Polariscope, 578. See also Saccharimeter 

micro, 84 
Polariscope tube jacketted, 639 

short, for oils, 870 
Polarization at high temperature, 639 
of essentional oils, 871 
honey, 639 
lemon extract, 864 
molasses, 614 
orange extract, 873 
sugar, 578 
vinegar, 769 
Polarization of wine, 694, 703 
Polenske number, 483 
Poppy seed, 526 

oil, 526 
Pork, j[:omposition of, 216 

cuts of, 216 
Porter, 709, 712. See also Beer. 
Port wine, 689 

Potash determination, 304, 345 
Potassium myronate, 453, 457 
Potatoes, composition of, 273 
proteins of, 301 
starch of, 282 
Poultry, composition of, 216 
Preparation of sample. 55 
Preservatives, 815 

commercial food, 817 
in butter, 538 
in canned goods, 903 
in fish, 257 
in meats, 220, 232 
in milk, 177, 183 
in table sauces, 908 
of eggs, 266, 268 
references on, 838 
regulation of, 816 
Pressure pump, 20 
Process butter, 540 
Prolamins, 42 
Proof spirit, 677 
Prosecution, 10 
Protamins, 43 
Proteans, 44 
Proteins, 40 

coagulated, 44 

coniugated, 43 

derived, 44 

factor for, 40 

of barley, 277, 300 

of beer, 725 

of cereals, 296 

of condensed milk, 190 

of eggs, 262 

of milk, 125 



Proteins, of milk, calculation of, 153 

determination of, 145 

of peas, 300 

of potatoes, 30 r 

of rye, 277, 300 

of wheat, 277, 298 

secondary derivatives, 44 

simple, 41 

tests for, 41 
Protein grains, 90 
Proteolytic fermentation, 158, 202 
Proteoses, 44, 297 
Proto-albumose, 44, 45 
Proximate analysis, extent of, 53 

expression of results of, 

Prussian blue, 790, 811 

Ptomaines, 218 

Publication of adulterated foods, 10 

Pulfrich refractometer, 100 

Pycnometer, 57 

Pyroligneous acid, 764 

Quassiin, 727 
Quercitannic acid, 415 
Quevenne's lactometer, 132 
Quince essence, imitation, 884, 885 
Quotient of purity of sugar, 586 

Raffinose, 279, 577 

determination of, 620 
Rancidity, 473, 530 
Rape oil, 520 

test for, 52T 
seed, 520 
Raphides, 90 
Reagents, 35, 90 

references on, 38 
table of, 26-34 
Red colors, 783, 784, 788, 792, 804 
Red ochre in sausages, 238 
Red pepper. See Cayenne and Paprika 
Red wines, 684, 689 
Red wood, 444 
References on beer 756 

butter, 562 

canned goods, 927 

cereals, 361 

cocoa, 406 

coffee, 406 

colors, 813 

dietetics, 49 

distilled liquors, 758 

eggs, 270 

flavoring extracts, 886 

flesh foods, 258 



INDEX. 



949 



Referenc es on fiood economy. 49 
inspection, ir 

fruit products, 927 

fruits, 361 

general analytical methods, 79 

laboraton.- equipment, 38 

leavening materials, 364 

liquors, 756 

microscope, 98 

milk, 208 

oils, 561 

preservatives, 838 

reagents, 38 

refractometer, 122 

spices, 468 

sugars, 650 

tea. 406 

vinegar, 7 78 

wine, 757 
Refractometer, 100 

Abbe, 100 

.\magat and Jean, 100 

butyro, 100, loi 

heater for, 102 

immersion, 11 1 

in oil analysis, 477 

Pulfrich, 100 

sliding scale for, 107 

tables for, 104, 105, lit,, 
116, 120, 121 

Wollny, 100, 139 
Reichert-Meissl method, 481 
Reichert number of butter, 549 
Reinsch's test for arsenic, 728 
Relishes, 906 
Renard's test for p)eanut oil, 523 

for rosin oil, 527 
Renovated butter, 540 

distinction from butter 
and oleomargarine, 546 
Resins, 89 

Respiration calorimeter, 2 
Rice, composition of, 272 

microscopical structure of, 310 
starch, 282 
Riche and Bardy methyl alcohol method, 

751 
Richmond's cane sugar method, 185 
sliding milk scale, 153 
Ritsert's tests for acetanilide, 859 
Ritthausen's method for milk proteins, 145 
Rneser's mustard oil method, 457 
Ropy milk, 130 
Roquefort cheese, 202 
Rose, attar of, 882 
extract, 2,?)2 



Rose, extract, standards, 882 
rose oil in, 883 
Rosin oil, 527 
Rota's color scheme, 797 
Rubner's fuel value factors, 48 
Rum, 742 

composition of, 742 
essence, 743 

methods of analysis, 745 
new, 743 
standards, 742 
Rye, composition of, 271 

microscopical structure of, 308 
proteins of, 300 
starch, 281 
Saccharimeter, 578 

double wedge, 581 
forms of, 583 
normal weights for, 583 
scales compared, 583 
single wedge, 579 
Soleil-Ventzke, 578 
triple shadow, 581 
Saccharimetry, 578 
Saccharin, 842 

detection of, 843 
determination of, 844 
Saccharine products, 565 
Saccharoses, 565 
Safflower, 789 
Saffron, 789 
Sago, 283 
Saleratus, 332 
Salicylic acid, 825 

detection of, 825 
determination of, 826 
in meat, 233 
in milk, iSo 
Salmin, 43 
Salted meats, 218 
Sample, preparation, 55 
Sanatogen, 15S 
Sanose, 158 

Saf)onification, 472, 484, 4S6 
Sarcolemma, 211 
Sausages, 223 

ash of, 225 
color of, 224 
composition of, 223 
fat in, 226 
glycogen in. 234 
horseflesh in, 234 
methods of analysis, 225 
starch in, 223 
water in. 225 
Sauteme wine, 68^. 688 



950 



INDEX. 



Savory extract, standards, SSi 

oil, standards, 8Si 
Sawdust, 450 
Schied m schnapps, 744 
Schenk beer, 708 

Schlegel's method for colors in pastes, 350 
Schreiner's colorimeter, 77 
Schultze's reagent, g^ 
Sclerenchyma, 87 
Scovell sampling tube, 131 
Sealed samples, 6, 159 
Semolina, 347 

Separatory funnel support, 68 
Sericin, 42 
Sesame oil, 518 

adulteration of, 519 
tests for, 519 
seeds, 518 
Sherry wine, 687 

Short's method for fat in cheese, 205 
Shredded wheat, 352 
Sieve tubes, 89 
Silent spirit, 731 
Sinabaldi's asaprol method, 83S 
Sinalbin, 454 

mustard oil, 454 
Sinigrin, 453 
Sinks, 1 7 
Sitosterol, 522 
Smoked meats, 218 
"Soaked," goods, 905 
Soda, determination of, 304, 345 
Sodium benzoate, 827 

bicarbonate, 332 

bisulphite, 833 

carbonate, in milk, 180, 182 

hydroxide, tenth-normal solution, 35 

salicylate, 825 
Soja bean meal, 357 
Soleil-Ventzke saccharimeter, 578 
Sorghum, 573 

Sostegni and Carpentieri's test, 794 
Souring of milk, 129 
Sour milk, 139 
Soxhlet ex-tractor, 63 
Soxhlet's milk sugar method, 150, 152 
Spaghetti, 347 
Sparkling wine, 685, 691 
Spearmint, extract, 880 

standards, 880 
oil, 880. 
Specific gravity bottle, 57 

of beeswax, 643 
of liquids, 55 
of liquors, 657 
of milk, 131 



Specific gravity of milk serum, t66 

temperature cor- 
rection for 133 
of oils, 474 
of vinegar, 764 
Specific rotary power, 584 
Spent tea leaves, 375 
Spices, 408 

adulterants of, 413 
alcohol extract of, 410 
ash of, 409 
crude fiber of, 411 
ether extract of, 410 
lime in, 410 

methods of analysis, 408 
microscopical examination of, 412 
nitrogen in, 410 
references on, 468 
starch in, 411 
volatile oil of, 411 
Spiial ducts, 89 
Spirits, cologne, 731 
distilled, 730 
neutral 731 
silent J 731 
standards, 730 
velvet, 731 
Spirit vinegar. 760, 763 
Spoon test for butter, 549 
Sprengel tube, 60 

Stahlschmidt's caffeine method, 374 
Standards for allspice, 424 

anise extract, 880 

oil, 880 
beer, 711 
brandy, 740 
butter, 535 
cassia, 428 

extract, 880 
oil, 880 
cayenne, 443 
celery seed extract, 880 

oil, 880 
cheese, 203 
cinnamon, 428 

extract, 881 
oil, 881 
clove extract, SSi 

oil, 881 
cloves, 418 
cocoa, 402 
cream, 195 
foods, 4 
ginger, 450 

extract, 881 
oil, 881 



INDEX. 



951 



Standards for ice cream, 199 
lard, 556 
lemon extract, 861 

oil, 861 
mace, 460 

maple products, 572 
meats, 218 
meat extracts, 241 
milk, 160, 162 
molasses, 621 
mustard, 459 
nutmeg, 464 

extract, 881 
oil, 881 
olive oil, 513 
pepper, 435 
renovated butter, 541 
rum, 742 
savory extract, 881 

oil, 881 
staranise extract, 881 

oil, 881 
starch sugar, 574 
sugars, 566, 574, 772 
sweet basil extract, 881 
oil, 881 
majoram extract, 881 
oil, 881 
thyme extract, 881 

oil, 88 E 
vanilla extract, 853 
vinegar, 770 
wine, 689 
whiskey, 733 
Standard solutions, equivalents of, 36 

refractometric readings 
of, 120 
Staranise extract, standards, 881 

oil standards, 881 
Starch, 47, 89, 279 

arrowroot, 282 
barley, 281 
bean, 282 
buckwheat, 281 
classification of, 280 
corn, 281 
detection cjf, 279 
determination of, 283 

by acid conversion, 283 
by diastase method, 283 
in baking powder, 343 
in cereals, 283, 296 
in milk, 185 
in sausages, 233 
in spices, 411 
oat, 282 



Starch, pea, 282 

potato, 282 
rice, 282 
rye, 281 
sago, 283 
syrup, 575 
tapioca, 282 

under polarized light, 283 
wheat, 281 
Stearin, beef, 541 

cottonseed, 517 
lard, 555 
Sterilized butter, 540 
Still, alcohol, 659 

fractionating, 67 
nitrogen, 73 
water, 22 
wine, 685 
Stilton cheese, 202 
Stokes' milk centrifuge, 136 
Stone's method of carbohydrate separation 

295 
Storch's method for boiled milk, 155 

mucoid protein, 127 
Stout, 709, 712. See also Beer 
Strippings, 128 
Stutzer's gelatin method, 231 
Suberin, 89 
Sucrate of lime, 196 
Sucrose. See Cane sugar 
Suction pump, 19 
Suet, 529 
Sugar, 561 

beet, 569 

brown, composition of ash, 567 

cane, 566, 567 

classification of, 565 

composition of, 568 

grape. See Dextro.se 

in fruits, 566 

maple. See Maple syrup 

methods of analysis, 585 

muscovado, 567 

organic non-sugars in, 586 

quotient of purity, 586 

raw, 568, 569 

references on, 650 

refining, 570 

standards, 566, 572, 574 

ultramarine in, 570, 590 
Sulphur, determination of, 305 
Sulphuric acid in baking chemicals, 346 

in vinegar, 767 
Sulphuring, 833 
Sulphurous acid, 833 

detection of, 834 



952 



INDEX. 



Sulphurous acid, determination of, 834 

in meat, 220, 232 
Sunflower oil, 526 

seeds, 527 
Sweet basil extract, standards, 881 

oil, standards, 881 
Sweeteners, artificial, 842 
Sweet majoram extract, standards, 881 

oil, standards, 881 
Sweet wine, 685, 690 
Syrup, analysis of, 613 
ashing of, 614 
maple. See Maple syrup 
mixing, 576 
starch, 576 
total solids in, 613 
Sy's lead method, 630 



Table sauces. 905 

preservatives in, 90S 
Tallow, 529 
Tannin in cloves, 415 
in tea, 370 
in wine, 704 
Tapioca, 282 
Tartaric acid in baking powder, 339, 340 

in fruit products, 920 
Tartrate baking powders, 332 
Tea, 365 

adulteration of, 374 
ash of, 368, 369 
astringents in, 377 
caffeine in, 372, 373 
composition of, 366, 367 
exhausted leaves in, 375 
extract of, 370 
facing of, 374 
foreign leaves in, 376 
leaf, characteristics of, 376 
methods of analysis, 368 
microscopical examination of, 378 
references on, 406 
spent leaves in, 375 
stems in, 376 
tablets, 377 
tannin in, 370 
theine in, 372, 373 
Tecnique, 82 

Teller's method of separating wheat pro- 
teins, 298 
Theine, 372 
Theobromine, 396, 400 
Thompson's boric acid method, 823 
Thyme extract, standards, 881 
oil, standards, 881 



Tin, action of fruits and vegctaljles on, 892^ 
893, 895 
determination of, 900, 902 
salts in molasses, 625 
Tintometer, Lovibond, 78 
Titer test, 500 

Tocher's sesame oil test, 519 
Tomato ketchup, 906 

coloring in, 907, 908 
preservatives in, 908 
Tonka bean, 852 

tincture, 853 
Trillat methyl alcohol test, 750 
Turmeric, 450 

as an adulterant, 452 
microscopical structure of, 451 
tests for, 453, 789 

Ultramarine blue, 791, 810 

in sugar, 570, 590 
Uno beer, 714 
Unsaponifiable matter^ 501 

Vacuoles in yeast cells, 330 
Vanilla bean, 849, 850 

exhausted, 851 
Vanilla extract, 849 

adulteration of, S53 
alcohol in, 860 
alkali in, 852 
artificial, 854 
caramel in, 860 
color quotient of, 86i 
composition of, 851 
coumarin in, 854 

determination of, 858 
glucose in, 860 
glycerin in, 860 
methods of analysis, 855 
prune juice in, 854 
resins in, 855 
standards, 853 
tannin in, 856 
tonka in, 854 
vanillin in, 85O, 858 
Vanillin, 851 

determination, 856, 858 
microscopical structure, 860 
Van Slyke's protein formula, 153 

method of nitrogen separation 
in cheese, 205, 206 
in milk 146 
Vaporimeter, 675 
Veal, composition of, 214 

cuts of, 214 
Vegetable colors, 787 



1 



INDEX. 



953 



"\'egetable colors, in sausages, 239 
\'egetables, 273 

ash, of 302 

composition of, 273 

methods of proximate aaaly- 

sis of, 276 
references on, 361 
\'entilation, 15 
Vermicelli, 347 
Vessels, 8q 

Villivecchia and Fabris' sesame oil test, 520 
Vinegar, 759 

acidity of, 765 

acids of, 766 

adulterated, 776 

adulteration of, 770 

alcohol in, 766 

apple, 771 

arsenic in, 778 

artificial, 772 

ash of, 761, 764, 773 

solubility and alkalinity of, 
764 

beer, 762 

caramel in, 777 

cider, 760, 771 

artificial, 772 

composition of, 760 

copper in, 778 

distilled, 763, 771 

extract of, 764 

furfural in, 777 

glucose, 763, 771 

grain, 771 

Hortvet number of, 76S 

hydrochloric acid in, 767 

lead in, 777 

acetate, test for, 768, 777 
number of, 768 

levulose in, 770 

malic acid in, 767 

malt, 762, 771 

manufacture of, 760 

metallic impurities in, 777 

methods of analysis, 764 

mineral acids in, 766, 767 

molasses, 763 

nitrogen in, 765 

phosphoric acid in, 764 

polarization of, 769, 774 

reducing sugars in, 770 

references on, 778 

residue of, 772 

specific gravity of, 764 

spices in, 777 

spirit, 771 



Vient^ar, standards, 770 

sugar, 771 

sugars in, 769, 774 

sulphuric arid in, 767 

tartrate in, 7(k) 

tests on, 775 

varieties of, 759 

volatile acids of, 76 

wine, 761, 771 

wood, 764, 777 

zinc in, 777 
Vinous fermentation, 654 
\'iscogen, 196 
Viscosity of cream, 196 

of oils, 477 
Vitellin, 43 

Waage's Bombay mace test, 468 
Walnut ketchup, 907 
Water-bath, 21 
Water glass, 266 
Waterhouse butter test, 550 
Weiss beer, 709 

Werner-Schmidt method for fat in cheese, 205 

in milk, 139 

Westphal balance, 56 

West's benzoic acid method, 832 

Wheat, 271, 272 

ash of, 302 

composition of, 271, 272 
microscopic structure of, 306 
proteins of, 277, 298 
shredded, 352 
starch, 281 
Whiskey, 731. See also Distilled liquors 

adulteration of, 73S 

aging of, 732 

American, 735 

Bourbon, 732, 734, 736, 737 

British, 735 

composition of, 734 

imitation, 738 

Irish, 732. 734, 735 

manufacture of, 731 

methods of analysis, 745 

rye, 732, 734, 737 
Scotch, 732, 734, 735 
standards, 733, 734 
Wijs's iodine absorption method, 492 
Wild's saccharimeter, 583 
Wiley's bromine pipette, 495 
Wiley and Ewell's double dilution sugar 

method, 149 
Wine, 684 

acidity of, 696 
added alcohol in, 695 



954 



INDEX. 



Wine, adullcration of, 691 
ameliorated, 691 
Burgundy, artificial, 692 
California, 688 
cane sugar in, 693 
Cazeneuve's color method, 705 
chaptalizing, 693 
claret, 687 

artificial, 692 
classification of, 685 
coloring matter in, 704, 705 
composition of, 686 
corrected, 691 
cream of tartar in, 702 
"dry," 690 

Dupre's color metlnul, 705 
extract in, 696, 697 
fortified, 685, 690 
fruit other than grape, 695 
glycerin in, 703 
hocks, 689 
Madeira, 685, 686 
Malaga, artificial, 692 
malic acid in, 702 
manufacture of, 684 
methods of analysis, 696 
modified, 691 
natural, 685 

non-volatile acids in, 701 
plastering, 692 
polarization of, 703 
port, 689 

potassium sulphate iii, 704 
raisin, 691 
red, 684, 689 
reducing sugar in, 703 
references on, 757 
sherry, 687 

artificial, 692 
sparkling, 685, 691 
standards, 689 
still, 685 
sweet, 690 
tannin in, 704 
tartaric acid in, 701 
varieties of, 687 



Wine, vinegar, 761 

volatile acids in, 696 
watering of, 694 
white, 684, 689 
yeast of, 684 
Wintergreen extract, 878 

adulteration of, 878 
wintergreen oil in, 878 
oil of, 878 
Winton lead number, 628, 768 
Wollny milk fat refractometer, 100, 139 
tables for using, 141 
table for converting Wollny de- 
grees into «D, M,5 
Woodman and Newhall's color quotient, S61 
and Taylor's caffetannii: acid 
method, 383 
Wood vinegar, 764, 777 
Wool, double dyeing method with, 793 
dyeing of, 793 
for color tests, 793 
vegetable colors on, 795 

Xanthin, 46, 211 
Xantho-proteic reaction, 41 
Xylan, 285, 288, 296 
Xylose, 285, 288, 296 

Yeast, 327 

adulteration of, 331 

composition of, 329 

compressed, 328 

dry, 328 

in cider, 678 

in wine, 684 

microscopical examination of, 329 

starch in, 331 

testing, 330 

vacuoles in, 330 
Yeast extracts, 246 
Yellow colors, 783, 785, 788, 792, S06 

Zega's test for oleomargarine, 553 
Zein, 42, 300 
Zinc salts, 897 

determination of, 900 



PLATE I. 



CEREALS. 




Fig. 121. — Barley, Xiio. 

Transverse section, showing in order, pericarp, 

seed coats, aleurone layer, and starch cells. 



Fig. 122. — Barley, X55. 
Surface \'iew of epidermis -with hairs. 




r 



Fig. 123. — ^Barley, Xi2^. 
Surface view of upper chaff layer. 



Fig. 124. — Barley Starch, X220. 



PLATE II. 



CEREALS. 



-^ 







^ 



Fig. 125. — Buckwheat, Xiio. 

Transverse section through part of pericarp, seed 

coat, and part of endosperm. 




Fig. 126. — Buckwheat, Xiio. 
Surface view of scutellum. 




Fig. 127. — Buckwheat, ^-^iio. 
Surface section. .>\leurone or proteid layer. 










« 



o\ 








Fig. 128. — Buckwheat Starch, X 220 
Starch granules separated 



PLATE III. 



CEREALS. 



% 
^ 



^ 




Fig. 129. — Buckwheat Starch, Xiio. 
Starch grains in masses. 



Fig. 130. — Corn, Xiio. 
Transverse section through pericarp, seed coat, 
proteid layer, and part of endosperm, showing 
starch cells. 




Fig. 131. — Com, Xno. 
Svirface view showing two layers of the mesocarp^ 



Fig. 132. — Corn, Xiio. 
Surface section. Proteid !av»r. 



PLATE IV. 



CEREALS. 



{<: 



.'^ 















f'iG. 133.— Com Starch, X220. 






• .;?V^«' -*? 






• •«,-.-; J.. 



Fig. 134. — Corn Starch, X22C. 
With polarized light. 




Fig. 135. — Oat, Xiio. 
Transverse section through chaff. 



Fig. 136. — Oat, Xiio. 
Surface section. Proteid layer with fragments of 
epidermis and hairs. 



PLATE V. 



CEREALS. 




Fig. 137. — Oat, Xiio. 
Surface view of upper chaff layer. 



Fig. 138.— Oat XSS- 
Surface view of epidermis and hairs. 





Fig. 139. — Uat Slarcli, X220. 



Fro. 140. — Rice, Xiio 

Transverse section throus^h seed coat and part of 

endosDftrm 



PLATE VI. 



CEREALS. 




Fig. 141. — Rice, Xiio. 
Surface section through starch cells. 



Fig. 142. — Rice, ^Ciio. 
Surface view of upper chaff laver 















■5vs 



^f^c'^^ 



:*? 












'^<',.-s<vV;' 












^it^'-^|k 










Fig. 143. — Rice Starch, X220 



Fig. 144. — Rye, X 18 
Transverse section through the entire grain. 



PLATE VII. 



CEREALS. 





j Fig. 145. — Rye, Xiio. Fig. 14(1. |<y,, .:iio. 

( Transverse section through pericarp, seed coat, Surface view of epidermis and underlying layers, 
aleurone layer, and starch cells of endosperm. 





Fig. 147. — Rye, Xiio. 
Surface view of epidermis and of seed coai. 



Fig. 148. — ^Rye Starch, X 22c 



PLATE van. 



CEREALS. 



..i^nnrim vi 



^ 




Fig. 149. — \Mieat, Xiio. Fig. 150. — Wheat, Xiio. 

Transverse section through pericarp, seed coat, Surface view of outer and inner epidermis Also 
proteid layer, and starch cells of endosperm. showing proteid layer. 




^•> 



•Vv^ 



Fig. 151. — Wheal, .^110. 
Surface view of epidermis, with hairs. 



Fig. IS2. — \\ heat Mari-h, ,x220. 



PLATE IX. 



LEGUMES. 






?c;^ 



9 'V 



1:. 




Fig. 153. — Bean, ,\iio. 
Transverse section through starch cells. 



Fig. 154. — Bt-an Starch, X220 



.-■. \.^' ]j»tgs:zL.',\ 





Fig. 155.— Beau, Xno. Fig. 156.— Leniil, X no. 

Transverse section through hull, showing palisade Transverse section through hull and part of endo- 

cells of epidermis, and underlying hypoderma. sperm, showing some of the starch cells. 



PLATE X. 



LEGUMES. 




Fig. 157 — Lentil, Xiio. 
Surfare view of epidermis. 



Fig. 158. — Pea, Xiio. 
Transverse section through hiill and seed coat, 
showing outer paHsade cells and underhing 
hA-poderma. 





Fig. 159 — Pea. Xiio. 
Surface section through base of palisade laver. 



Fig. 160. — Pea. ^:iio. 
Powdered pea hulls. 



PLATE XI. 



LEGUMES. 




Fig. i6i. — Pea, Xiio. 
Surface view of palisade cells. 



Fig. 162. — Pea, Xiio. 
Transverse section through starch cells. 




V- 



n >r 






Fig. i6_5. — Pea, X30. 
Transverse section through starch cells. 



Fig. 164. — Pea Starch X220 



MISCELLANEOUS STARCHES. 



PLATE XII. 




Fig. 165. — Potato Starch, X220. 



Fig. 166. — Potato Starch, X220. 
With polarized light. 




• ■ ' 



Fig. 167. — Arrowroot Starch, X220, 




Fig. 168. — ^Tapioca Starch, X220. 
(Cassava.) 



TURMERIC. SAGO. 



PLATE XIII. 




Fig. 169. — Turmeric, X 70- 
Transverse section through rhizome. 




Fig. 170. — Turmeric, X no. 

Longitudinal section. Note spiral ducts through 

the center. 




.'4' 



'V 



Fig. 171. — Powdered Turmeric, X 110. 

[hewing starch grains, fragments of cell tissue, 

coloring matter, etc. 



n^^ 



'■^. 



JTA 



Fig. 172. — Sago -Starch, X220. 



/ 




PLATE XIV. 



COFFEE. 





Fig. 173. — Raw Coffee, X no. Fig. 174.— Roasted Coffee, X130. 

Transverse section of outer portion of endosperm. Transverse section through parenchyma of endo- 
sperm. 




#, 




^iW.t% 







Fig. 17;. — Coffee, Xno. 
Surface view of seed coat. 



Fig. 176. — Coffee, Xnc 

Roasted, ground coffee, showing fragments of 

endosperm parenchvma and of 5eed coat. 



PLATE XV. 



COFFEE. CHICORY. 



m' 






Fig. 177. — Adulterated Coffee, X130. 
Dark masses of roasted pea starch are shown, 
with transparent fragments of- the paHsade 
cells of the pea-hull. 



Fig. 178. — Adulterated Coffee, ^130. 
The vascular dugts of chicorj^- show most con- 
spicuously in this field. 




Fig. 179. — Chicory, X25. 
Transverse section through the root. 



Fig. 180. — Chicory, Xno. 
Transverse section. 



PLATE XM. 



CHICORY. COCOA. 




Fig. iSi. — Chicory, Xiio. 
Tangential section, shovdng reticulated ducts and 
wood parenchyma. 



Fig. 1S2. — Chicory, Xiic 

Radial section, showing bark parenchyma and 

milk ducts. 





Fig. iSj — Chicory-, Xiio. 

Roasted and ground, showing fragments of 

ducts and other tissues. 



Fig. 1S4. — '":::!. ■ ::; 

Transverse section through periphery of seed, 

seed coats, and cotvledon. 



PLATE XVH. 



COCOA. 




Fig. 185. — ruwdered Cocoa, X no. 




.,..^' 



Fig. 186. — Adulterated Cocoa, X no 

Showing admixture of arrowroot with the cocoa 

powder. 





1 Fig 187. — Cocoa Shell, Xiio. 

Iransverse section through epidermis, pulp, and 
(mucilaginous layers of the pericarp and seed 
coat. 



Fig. 188.— Cocoa Shell, Xno. 
Longitudinal section through shell 



PLATE XVIII. 



TEA. SPICES. 



\ 




Fig. 189.— Tea, X55. 
Transverse section through midrib of leaf. Note 
the palisade layer below the upper epidermis, 
the inner wood vessels above the center, and 
the parenchyma of the pulp. 



Fig. igo. — IV. i, x no. 
Surface \aew of lower epidermis, wth stomatn and 
one of the haiis. 




Fig. iqi. — Allspice, X9- 
(Transverse section through the entire berry, show- 
ing the two cells, with kidney shaped seed in 
each. 



Fig. ..,.. ..-.,.- -^ , ,7c. 

Transverse section through pericarp, showing oil 

spaces and stone cells. 



PLATE XIX 



SPICES. 




V^l 



V 



Fig. 193.— AlL-picc ScL-d Xiio. Fig. in:. \' lii. . ><( <i, :<iio. 

Transverse section through seed shell and part of Transverse section through the resinous portion of 

the seed coat, showing port wine colored lumps 
of gum or resin. 



embryo, showing starch cells. 



"'*.;#'^> 




,;^ if} 




# 





•^' 



% 



Fig. 195. — Powdered Allspice, Xno. 
Showing stone cells, resinous lumps, and starch. 



Fig. 196. — Adulterated Allspice, Xno. 
Showing a large fragment of the seed skin of 
cayenne at the left. 



SPICES. 



PLATE XX. 




Fig. 197. — Cassia Bark, X45. 
Transverse section through the bark. 



Fig. 198. — Cassia Bark, X45. 
Longitudinal section. 




Fig. 199.— Cassia Bark, Xiic. Fig. 200.— Cassia Bark, Xiio. 

Trinsverse section, sho^-ing cork cells, parenchy- Longitudinal section, showing bunches of bast 
ma. and stone cells. fibers at the left, starch cells in the center, and 

stone cells at the right. 



PLATE XXL 



SPICES. 





Fig. 20I. — Ceylon (iiinamon Bark, Xiio. FiG. 202. — Ceylon Cinnamon Bark, X 1 10 

Transverse section, showing many bast fibers and Longitudinal section, showing bast fibers, stone 
starch cells. cells, and parenchyma. 




Fig. 203. — Powdered Cassia, Xiio. 
Showing stone cells, starch, and corky tissue. 



Fig. 204. — Powdered Cassia, Xiio. 
Showing bast fibers and starch. 



PLATE XXII. 



SPICES. 




0^- 



A 



'^ 



^ 




Fig. 203. — Powdered Cassia, X no. 
^howinsf lars;e bast fiber and starch grains. 



Fig. 206. — Adulterated Cassia, Xno. 
A mass of foreisrn bark. 




Fig. 207. — Cayenne, Xno. 
Transverse section through pericarp. 



Fig. 2cS. — Cayenne, Xno. 
Transverse section through seed coat and part of 
endosperm. Collapsed parench)-ma cells sepa- 
rate endosperm from long epidermal cells. 



SPICES. 



PLATE XXIII. 




Fig. 209. — Cayenne, Xiio. 
Surface view of fruit epidermis. 



t>,^^ 



w 



Fig. 210. — Cayenne, Xiio. 
Surface view of two layers of seed coat. 




Fig. 2 1 1 . — Powdej-ed Cayenne, X 1 10. 
.\ large mass of fruit epidermis. 



Fig. 212. — Powdered Cayenne, Xno. 
Showing chiefly two of the seed coat layers. 



PLATE XXIV. 



SPICES. 



4^^-^."-^^ 








•o. 



Fig. 213. — Adulterated Cayenne, X130. 

Corn and wheat starch and cocoanut shells appear 

chiefly. A bit of cayenne is shown at the right. 



Fig. 214. — Adulterated Cayenne, X214. 

The central mass is ground red wood, surrounded 

by corn starch grains. 




Fig. 215. — Clove, X65. 
TTransverse section from the center out^vard to 
i epidermis, sho\\-ing parenchyma. 



Fig. 216. — CiuNc, \iio. 
Transverse section near epidermis, showing large 
oil cavities. 



SPICES. 



PLATE XXV. 





Pig. 217.— Clove, X2S. 
LonffinirHnal section through entire clove. 



Fig. 218— Clove, X70. 
Central longitudinal section, showing duct bundles. 




Fig 2ig. — Clove, Xiio. 
Surface view of epidermis 



Fig. 220.— Powdered Cloves, Xi30- 
Dense, spong\' tissue, \\-ith small oil drops. 



SPICES. 



Pilate xxvi. 







Fig. 221. Ll.y.L Stem, X70. FiG. 222. — Clove Stem, X25. 

Transverse section through outer part of stem. Central longitudinal section through entire stem, 



showing bast fibers at the left, parenchyma in 
the center, and stone cells near the epidermis. 



showing bast fibers in the center, and stone cells 
at the right. 




Fig. 223. — Clove Stem, X 70. 
Longitudinal section, showing the stone cells. 



Fig. 224. — Powdered Clove Stems, Xiio 

Showing fragments of tissues, .stone cells, and bast 

fibers. 



SPICES. 



PLATE XXVII. 



t 




Fig. 225. — Powdered Clove Stems, Xiio. 
Showing bundle of bast fibers. 



-;iy;«i^(^fc-^ 



^'■'m 



% 




Fig. 226. — Adulterated Cloves, X130. 
Showing chiefly stone cells of cocoanut shells. 











/ 



Fig. 227. — Adulterated Cloves, X130. 
With large admi.xture of cocoanut shells. 






Fig. 228. — Ginger, X no. 

Transverse section, showing starch cells with 

contents. 



PLATE XXVIII. 



SPICES. 





\ 



Fig. 229. — Ginger, Xno. Fig. 230. >. - , ■;iio. 

Transverse section, showing parenchyma, starch Longitudinal section, showing spiral ducts and 
grains, and duct vessels. pigment cells. 



L.' 




4 



\ 









Fig. 231. — Ginger Starch, X220. 




Fig. 232. — Adulterated Ginger, X 130. 
A mass of wheat bran tissue is most conspicuous. 



PLATE XXIX. 



SPICES. 







Fig. 233. — Adulterated Ginger, X130. 



Fig. 234. — Adulterated Ginger, X130. 



The central dark mass is a yellow fragment of Containing a large admixture of corn and wheat 
turmeric. starches 




Fig. 235.— Penang Mace, Xito. Fig. 236.— Bombay or Wild Mace, Xno. 

Transverse section through epidermis and oil cells, Transverse section through outer layers, showing 
showing also parenchyma with contents of yellow and red resinous lumps, 

amylodextrin. 



PLATE XXX. 



SPICES. 




Fig. 237. ^Nutmeg, Xiio. 
Transverse section through the exterior and in- 
terior teguments of the seed and part of the 
endosperm, showing starch cells. 



Fig. 238. — Nutmeg, X25. 
Transverse section near exterior of seed. 





Fig 239. — Nutmeg, Xiio. 

Surface view of seed coat, shomng also portions of 

underlying tissues. 



Fig. 240. — Powdered Nutmeg, Xiio. 



PLATE XXXI. 



SPICES. 




Fig. 241.— WTiite Muit.ird, Xiio 
Transverse section through mucilaginous epider- 
mis, sub-epidermal parencli\Tna layer (square 
cells), palisade cells, and broken parenchjTiia 
laver of the hull. 



Fig. 242. — WTiite Mustard, Xno. 

Transverse section through the tissue of the 

radicle. 




Fig. 243. — WTiite Mustard Xiio 
Surface v^ew of two layers of the hull or seed coat- 



Fig. 244. — \Miite Mustard. Xiic. 

Surface section through paUsade cells and under- 

Ijing layer of the seed coat. 



SPICES. 



PLATE XXXII. 




Fig. 245. — Blark Mu.-tard, Xiio. 
Transverse section, showing fragments of the epi- 
dermis and dark colored palisade cells of the 
seed coat. 



Fig. 246. — Black Mustard, Xno. 
Surface view of two of the seed coat lavers. 




^SBl 




^ 



Fig. 247. — Ground Mustard, X 130. 
Ground without removal of the oil. 



Fig. 24S. — Ground Mustard Hulls, Xno 



SPICES. 



PLATE XXXIII. 





liG. 249. — Dakota Mustard Flour, X no. 
Dark spots show starch grains of foreign weed 
seed, stained with iodine. 




Fig. 250. — Aduherated Mustard Flour, X 130. 
Showing masses of wheat starch. 





Fig. 251. — Pepper, X no. 
ransverse section through inner part of pericarp 
(including parenchyma and seed coat layers) and 
portion of ptrisperm, showing starch and oil 
cells. 



Fig. 252. — Pepper, Xno. 
Surface view of hypodermal layer. 



PLATE XXXIV. 



SPICES. 




Fig. 253. — Pepper, Xiio. 
Fransverse section through outer part of pericarp, 
showing epidermis, underlying stone cell layers, 
])arenchyma, and seed coat. 



Fig. 254. — Pepper, Xno. 
Surface section through stone cell layer. 



^^•'*"^.,, 



, ■, ffv.«. •,'0 , ,, - rV • _>{vi?C. -. . 










■-^? 



# 

^Jl 

m 



•■* d- 



Fig. 255. — Pepper Starch, X220. 
Starch granules .separated. 



Fig. 256. — Pepper Starch, Xno 
Starch grains in masses. 



SPICES. 



PLATE XXXV. 




t 



►% 



*> 



.A 



!?^' 




/ 



Fig. 257. — Ground Pepper Shells, X no. 
Jilainlv showing; stone cells. 



:5T 



Fig. 258. — Adulterated Pepper, X 130. 
Showdng wheat and buckwheat starches. 







i^^f^iS?- ^ 



oS- 



"-:,. c 



■:9 



CO 



- 8 



Fig. 259. — Adulterated Pepjjer, X 130. 
Showing wheat, corn, and rice starches. 




t' 



" ^^J 



Fig. 260. — Adulterated Pepper, X 130. 
The large, lower mass shows buckwheat starch, 
while the finer-grained mass near the top is of 
pepper. 



PLATE XXXVI. 



SPICES. SPICE ADULTERANTS. 




*^ \ 







t^^ 
-,•*.»-». 

\ 




Fig. 261. — Adulterated Pepper, Xiio. Fig. 262. — Adulterated Pepper, X130. 

The central mass shows the sclerenchyma cells of Cayenne and wheat starch are the adulterants, 
olive stones. 






^. 



tK 



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Fig. 263. — Powdered Olive Stones, Xno. Fig. 264. — Powdered Cocoanut Shells, Xiio 



SPICE ADULTERANTS. 



PLATE XXXVn. 




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VA ;, 



Fig. 265. — Powdered Elm Bark, Xiio. 



Fig. 266. — Pine Sawdust, Xiio. 
Finely ground. 



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Fig. 267. — Pine Wood, Xiio. 
Transverse section. 




Fig. 268. — Pine Wood, Xnc 
Radial and tangential sections. 



PLATE XXXVIII. 



EDIBLE FATS. 




Fig. 269. — Pure Butter, X25. 
With polarized light and selenite plate. 





Fig. 270. — Process or Renovated Butter, X25. 
With polarized light and selenite plate. 



Fig. 271. — Oleomargarine, X25. 
With polarized Hght and selenite plate. 



PLATE XXXIX. 



EDIBLE FATS. 




Fig. 272. — Lard Stearin, Xiio. 
Leaf lard, crystallized from ether. 



Fig. 273. — Lard Stearin, X220. 
Leaf lard, crystallized from ether. 





Fig. 274. — Lard Stearin, X220. 
Back" lard, crystallized from ether. 



Fig. 275. — Lard Stearin, X480. 
"Back" lard, crystallized from ether. 



PLATE XL. 



EDIBLE FATS. 




Fig. 276. — Beef Stearin, X35. 
Crystallized from ether. 





Fig. 277. — Beef Stearin, Xno- 
Crvstallized from ether. 




Fig. 278. — Beef Stearin. • 
Crvstallized from ether. 



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